The global positioning system (global positioning system). Simply put, this is a worldwide 24-satellite satellite system. This system ensures that at any time, any point on Earth can be simultaneously observed four satellites, the satellite can be collected to ensure the observation points to the latitude and longitude and height to achieve the navigation, positioning, timing and other functions. This technology can be used to guide aircraft, ships, vehicles and personal, safe and accurate along the _select_ed route, arrive at the destination. Global Positioning System (gps) in the 20th century by the U.S. armed forces 70 years the joint development of a new generation of space satellite navigation and positioning system. Its main purpose is to land, sea and air three major areas of real-time, weather and global navigation services, and for intelligence gathering, surveillance and emergency communications, and other nuclear explosion, some military purpose, the United States an important component to dominate the global strategy. After 20 years of research laboratory at a cost of $ 30,000,000,000, to March 1994, the global coverage of up to 98% of the gps satellite constellation of 24 satellites has been laid to complete. gps global positioning system consists of three parts: the space segment --- gps constellation; ground control segment --- ground monitoring system; user segment --- gps signal receiver. ◆ gps predecessor To this end, U.S. Naval Research Laboratory (nrl) proposed the use of named tinmation 12-18 satellites global positioning height 10000km net programs, and in 67 years, 69 years and 74 years of the launch of a test satellite, In these preliminary test of the atomic clock on the satellite timing system, which is the basis of precise positioning gps system. The Air Force has put forward a 621-b of each constellation 4-5 3-4 satellites constellation program, in addition to one of these satellites orbit outside with the rest of the use of inclined orbit period of the 24h plans to pseudo-random code (prn)-based communication satellite ranging signals, and its powerful features, when the signal density of less than 1% of ambient noise, also can it be detected. Pseudo-random code is a gps system can be successfully used as an important basis for success. Navy's plan is mainly used to ship with low dynamic 2-D positioning, for the Air Force's plan to provide high dynamic service, but the system is too complicated. Since both systems simultaneously will cause a huge development costs and here are two programs designed to provide global positioning, so will be 2 U.S. Department of Defense in 1973 were combined, led by the Department of Defense Joint satellite navigation and positioning Projects Agency (jpo) leadership, will also _set_ up offices in the Los Angeles Air Force Space Division. Many members of the agency, including the U.S. Army, Navy, Marine Corps, Ministry of Communications, Defense Mapping Agency, NATO and Australian representatives.
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gps constitute
1. Space segment 2. Ground control segment 3. User segment Part of the user equipment gps signal receiver. Its main function is to capture a certain cut-off angle of the _select_ed satellite satellite under test and track the satellite operation. When the receiver to capture satellite signals to track, you can measure the pseudo-receiver antenna to satellite distance and the distance rate of change, demodulate the satellite orbital parameters and other data. Based on these data, the receiver of the micro-processing computer solution method can be carried out by targeting position calculation to calculate the latitude and longitude of the user geographic location, altitude, speed, time and other information. Inside the receiver hardware and software, and gps data, a complete post-processing software package gps user equipment. gps antenna receiver structure is divided into two parts unit and receiver unit. Receivers generally use both inside and outside the aircraft DC power supply. The purpose of _set_ting the machine is to replace the external power supply when the power is not interrupted continuous observation. Time with the outside power in the battery automatically charges. Turned off, the machine ram memory, battery power, to prevent data loss. At present various types of receivers become smaller, more light weight, easy to use field observations.
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gps principle
gps原理
gps原理
gps原理
gps navigation system, the basic principle is to measure the known location of the satellite to the user the distance between the receiver and then integrated multi-satellite data can know the exact location of the receiver. To achieve this, the satellite's position can be recorded under the satellite clock time, check out the satellite ephemeris. The distance between the satellite and the user to record the satellite signal propagation through the elapsed time to the user, and then multiplied by the speed of light received (due to the interference of the atmosphere ionosphere, the distance between the satellite and the user is not the real distance, but pseudo-range (pr): When the gps satellites work, it will continue to use 1 and 0 symbol composed of binary pseudo-random code (referred to as pseudo-code) launch the navigation message. gps systems use pseudo-code, a total of two, namely civilian c / a code and military p (y) code. c / a code frequency 1.023mhz, repeat the cycle of a millisecond, the code distance between 1 microsecond, the equivalent of 300m; p code frequency 10.23mhz, repeat the cycle of 266.4 days, code distance of 0.1 microseconds, equivalent to 30m. The code is in the p y formed on the basis code, confidential performance better. navigation data including satellite ephemeris, work status, clock corrections, ionospheric delay correction, atmospheric refraction correction and other information. It is the demodulation signal from the satellite out to 50b / s modulation in the carrier frequency emitted. navigation message included in each of the main frame 5 sub-frames per frame size 6s. the first three frames of the 10 code; repeated every thirty seconds, updated hourly. After the two were 15000b. navigation message in the main content of telemetry codes, code conversion, the first data blocks 1,2,3, including the most important was ephemeris data. When the user receives the navigation message, the extraction time and the satellite clock to do their comparison with their satellite and the user will be aware of the distance, and then use the satellite navigation message ephemeris data message when the projected location of the satellite launch , users wgs-84 geodetic coordinate system position, velocity and other information will be known. Gps satellite navigation system can be seen part of the role is to continue to launch the navigation message. However, the user receiver clock with the satellite using the satellite clock can not always synchronized, so in addition to the user's three-dimensional coordinates x, y, z, but also the introduction of a satellite and receiver Δt is the time difference between the as unknown, Then four equations out of these four unknown solutions. So if you want to know the location of the receiver, at least 4 months to be able to receive satellite signals. gps receiver can receive the exact timing can be used to nanosecond time information; used to forecast the next few months which the approximate location of the satellite ephemeris; used to calculate the required positioning satellite coordinates of the broadcast ephemeris a precision of several meters to tens of meters (different each satellite, are subject to change); and gps system information, such as satellite status. gps receiver measurements of code can be obtained from the satellite to the receiver, because it contains the receiver clock error of satellite and atmospheric propagation errors, it is called pseudorange. 0a code measured on the pseudo-range as ua code pseudorange, the accuracy is about 20 meters, measured on the p code p code pseudo-range is called pseudo-distance, accuracy is about 2 meters. By positioning, gps positioning into a single point positioning and relative positioning (differential positioning). Single point positioning is based on observations of a receiver to determine the way the receiver position, it can only view with pseudo-range measurements can be used to approximate the travel and other navigation and positioning. Relative positioning (differential position) is based on observations more than two receivers to determine the relative position between the observation point method can be used both pseudo-range observation phase observations can be applied, geodetic or engineering survey shall be phase observations using the relative positioning. Gps observations contained in the satellite and receiver clock error, atmospheric propagation delay, multipath errors, etc., when they are in the position calculation of satellite broadcast ephemeris error, and during most of the public when the relative positioning error is off_set_ or reduced, so will greatly enhance the accuracy, dual frequency receivers can be based on two observations in the atmosphere to off_set_ the major part of the ionospheric error in high precision when the distance between the receiver (the atmosphere is significantly different ) should be used in dual-frequency receiver.
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Theory of relativity to provide the necessary amendments gps
Gps satellite global positioning system timing signals to provide latitude, longitude and altitude information, accurate distance measurement requires precise clock. Therefore, we must use the exact relativistic effects gps receiver. Accuracy within 30 meters, gps receiver means it has used the relativistic effects. University of Washington physicist clifford m. will explain in detail, said: "If you do not take into account relativistic effects, the clock on the satellite and the Earth's clock is not synchronized." Relativistic fast-moving object that passes with time slower than static. will be calculated, each of gps satellite approximately 1.4 million kilometers per hour across the distance, which means it spaceborne atomic clocks on Earth every minute slower than 7 microseconds. The gravitational force exerted on time more relativistic effect. About 2 million meters of altitude, gps satellite by the gravitational pull by approximately one quarter on the ground. The result is faster satellite clock every 45 microseconds, gps to be included in the deviation of 38 microseconds. ashby explained: "If the satellite is no frequency compensation, 11 km a day will increase the error." (The practical effect is more complex because the satellite along an eccentric orbit, sometimes closer from Earth, sometimes too far away from another.)
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gps prospects
Gps technology with the all-weather, high precision and automatic measurement features, as an advanced measurement tools and new productivity, has been integrated into the national economic construction, national defense and social development in various applications. With the Cold War and the global economy booming, the U.S. government announced that from 2000 to 2006 period, to ensure against threats to U.S. national security under the premise sa cancellation policy, gps accuracy of civil signals improvement in the global context, the use of c / a code for a single point positioning accuracy is 100 meters to 20 meters, which will further promote the application of gps technology, increasing productivity, operational efficiency, scientific level and quality of life and stimulate market growth gps. According to the experts predict, in the United States alone, car gps navigation system, after 2000 the market will reach 30 billion U.S. dollars, while in China, the car navigation market will reach 50 billion yuan. Visible, gps technology market prospect is very impressive.
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gps features
The main features of the global positioning system: (1) weather; (2) global coverage; (3) three-dimensional high-precision constant speed time; (4) rapid time-saving efficiency: (5) widely used function.
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gps function
Global positioning system's main purposes: (1) terrestrial applications, including vehicle navigation, emergency response, physical observations of atmospheric, geophysical exploration, engineering surveying, deformation monitoring, crustal movement monitoring, urban planning control; (2) marine application , including the best range of ocean-going vessels route determination, real-time scheduling and navigation of vessels, marine rescue, marine hunting, and hydro-geological measurement and positioning of offshore platforms, sea-level monitoring; (3), aerospace applications, including aircraft navigation and aerial remote sensing attitude control, low earth orbit satellites, missile guidance, air rescue and protection of manned spacecraft exploration.
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gps applications
Mainly for ships, automobiles, aircraft navigation and other sports objects. For example: 1. The ship into port navigation and ocean water 2. Aircraft landing approach route guidance and 3. Vehicle autonomous navigation 4. Ground vehicle tracking and Urban Intelligent Traffic Management 5. Emergency rescue 6. Personal travel and outdoor adventure 7. Personal communication terminals (with the phone, pda, electronic maps integrated into) 1. Electricity, telecommunications, communications and other network time synchronization 2. Exact time of the grant into 3. Accurate feedback into the frequency 1. Various grades of land measurement, control measurements 2. Lofting road and various line 3. Underwater topographic survey 4. Crustal deformation measurement, deformation monitoring of dams and large buildings 5.gis Application 6. Construction Machinery (tire cranes, bulldozers, etc.) control 7. Precision Agriculture ◆ gps application in road engineering ◆ gps in car navigation and traffic management of Three-dimensional navigation is the primary function of gps, aircraft, ships, ground vehicles and pedestrians can use gps navigator for navigation. Car navigation system gps global positioning systems developed on the basis of a new technology. Gps car navigation system consists of navigation, self-navigation, microprocessor, speed sensors, gyro sensors, cd-rom drive, lcd monitor composition. gps navigation system with electronic map, radio communication networks, computer vehicle management information systems, can achieve vehicle tracking and traffic management, and many other features. (1) Vehicle Tracking Using gps and digital maps can display the actual location of the vehicle, and any enlargement, reduction, reduction, exchange diagram; can move with the target, the target always remains on the screen; also multi-window, multi-vehicle, multi-screen and tracking. Using this feature can be important to track vehicles and cargo transport. (2) to provide travel route planning and navigation Travel route planning provides a car navigation system, an important auxiliary functions, which include automatic route planning and design of artificial lines. Automatic route planning is determined by the driver starting point and destination, as required by the computer software automatically design the best driving route, including the fastest route, the easiest route, through the least number of freeway sections of the route calculation. Artificial line designed by the design of the driver according to their destination, start, end, and through point and so on, automatically create a route library. Route planning is completed, the display can be displayed on the electronic map design routes, and also shows the path and run the way cars run. (3) information search Provide users with the main object landmarks, such as tourist attractions, hotels, hospitals and other databases, the user can display the location on the electronic map. Meanwhile, the monitoring center console can be used to monitor any target within the region where the location information, vehicle information will be in digital form in the control center of the electronic map display. (4) Call Command Command Center can monitor the status of vehicle operation within the region, on a reasonable schedule of vehicles to be monitored. Command center can also be tracked at any time with the goal of the call, the implementation of management. (5) Emergency assistance Gps positioning and monitoring and management through the system in case of danger or accident of the vehicle for emergency assistance. Taiwan's electronic map display monitoring information and alerts help objectives, planning the best assistance programs, and sound and light alarm to remind the staff on duty for emergency treatment. ◆ gps for other applications Except for gps navigation, positioning, measuring, but because of space satellite gps system contained accurate clock time and frequency information can be released, therefore, to space satellites on the basis of accurate clock, under the supervision of the ground stations, transmission gps precision time and frequency is another important application, the application of the function of time or frequency can be precisely controlled laboratory services for many projects. In addition, meteorological data can be obtained using gps for certain experiments and engineering applications. Gps global positioning system was developed this year, the most high-tech to create a sense of one of its global, all-round nature of all-day navigation and positioning, timing, speed advantage is bound to get more and more in many fields wide range of applications. In developed countries, gps technology has been applied to transportation and traffic engineering. Currently, gps technology in China, road works and traffic management applications has just started, with China's economic development, highway construction and the rapid application of gps technology, the gradual deepening of its application in road engineering will broader and deeper, and play a greater role.
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gps Category
gps satellite receiver, many different types, depending on the model is divided into geodesic type, total station, regular type, hand-held, integrated; according to use into truck, ship type, on-board type, board type, spring-loading . Use classification by the receiver 1. Navigation type receiver This type of receiver is mainly used for moving vehicle navigation, it can give real-time vehicle location and speed. Such receivers generally use the c / a code pseudorange measurement, real-time positioning accuracy of single point lower, typically ± 25mm, when there sa of ± 100mm. Such receivers are cheap, widely used. According to different application areas, such receivers can be further divided into: Vehicle type - for vehicle navigation and positioning; Marine type - for ship navigation and positioning; Air-type - used in aircraft navigation and positioning. As the aircraft is fast, so in aviation requirements by the receiver can adapt to high-speed movement. Board type - for satellite navigation and positioning. As the speed of the satellite up 7km / s or more, and therefore require higher receiver. 2. Geodetic-type receivers Geodetic-type receivers is mainly used for precise measurement of geodetic and precision engineering. Such instrument is mainly carried out by carrier phase observations relative positioning, high positioning accuracy. Apparatus complex, more expensive. 3. Timing-type receiver The main advantage of this type of gps satellite receiver, high-precision time standards for timing, commonly used in the Observatory and radio communications in the time synchronization. 4.2.2 Classification of the carrier frequency by the receiver Single-frequency receiver L1 single-frequency receiver can only receive the carrier signal, measured values of carrier phase positioning. Can not effectively eliminate the impact of ionospheric delay, single-frequency receiver is only applicable to short baseline (<15km) of precise positioning. Dual-frequency receiver Dual-frequency receiver can receive both l1, l2 carrier signal. Frequency of using different ionospheric delay can eliminate the ionospheric delay on the impact of electromagnetic signals, it can be used for dual-band receiver for precise positioning of thousands of kilometers long. 4.2.3 Classification according to the number of receiver channels gps receiver gps satellites simultaneously receiving multiple satellite signals, in order to separate the received signals from different satellites to achieve the tracking of satellite signals, processing and measurement devices have such functions as the antenna signal path. According to the receiver by a channel can be divided into categories: Multi-channel receiver Sequential-channel receiver Multi-channel multi-channel receiver 4.2.4 Classification of works by the receiver Code dependent receiver Type of receiver is the use of code-related code-related technology has been pseudo-range observations. Square-type receiver Square-type receiver is the use of technology to remove the square of the carrier signal modulated signal to recover the complete determination of the carrier signal through the phase meter carrier signal generated by the receiver to the carrier signal and receiving the phase difference between the measured pseudo-range observations . Hybrid Receiver This instrument is a comprehensive advantages of the two receivers, both can get the code phase pseudorange, carrier phase can be observed values. Interferometric receiver The receiver is the gps satellites as radio sources, the use of interferometry to measure the distance between two stations. After 20 years of proven, gps system is a high precision, all-weather and global radio navigation, positioning and timing of the multi-functional system. gps technology has developed into a multi-area, multi-mode, multi-purpose, multi-model international high-tech industries. ◆ Type gps geodetic Geodetic-type receivers is mainly used for precise measurement of geodetic and precision engineering. Such instrument is mainly carried out by carrier phase observations relative positioning, high positioning accuracy. Apparatus complex, more expensive. Depending on use and accuracy, is divided into static (single frequency) receiver and dynamic (frequency) receiver that rtk. At present, gps technology development and practical application, the more well-known international manufacturer of the United States trimble (Tempo) navigation, Switzerland leica geosystems (Leica Geosystems), Japan topcon (TOPCON), the United States magellan (Magellan ) Company (formerly Thales Navigation), Shanghai Hua measured domestic navigation, the Haida and so on. trimble (Tempo) the geodesic-based gps receiver products are r8, r7, r6, and 5800,5700 and so on. Among them, the 5800 24 channel gps / waas / egnos receiver, it is the dual-band gps receiver, gps antenna, uhf radio and power supply are combined in a compact unit, with built-in trimble maxwell 4 Ultra chip tracking technology. Even in the harsh electromagnetic environment, is still less than 2.5 watts of power can be used to provide effective tracking of the satellite. Meanwhile, to expand the coverage and overall reduced operating errors, more than 5800 base stations to the same frequency manner. In addition, it trimble vrs network technology is fully compatible with its built-waas and egnos feature provides a non-real-time differential positioning base station. leica geosystems (Leica Geosystems) is the world's leading professional survey company, is a fast static and dynamic rtk pioneer. The gps1200 system receiver includes 4 models: gx1230 gg/atx1230 gg, gx1230/atx1230, gx1220 and gx1210. Which, gx1230 gg/atx1230 gg 72-channel, dual-rtk measuring receiver, receiver integrated radio, gsm, gprs and cdma module, with continuous checking (smartcheck +) function, waterproof (water 1m), dust, sand. Dynamic accuracy: Horizontal 10mm +1 ppm, vertical 20mm +1 ppm; static accuracy: Horizontal 5mm +0.5 ppm, vertical 10mm +0.5 ppm. Rtk when it 20hz to reach 30km or more away and can ensure the centimeter-level accuracy, the baseline the reliability of the 30 km is 99.99%. Japan topcon (Topcon) produced mainly gps receiver gr-3, gb-1000, hiper, net-g3 and so on. Which, gr-3 geodetic type receivers can be 100% compatible with the three major satellite systems (gps + glonass + galieo) of all available signals, there are 72 tracking channels, the use of anti-2 m drop rugged design, Bluetooth communications, the Home gsm / gprs module (optional). Static, rapid static accuracy: Horizontal 3mm +0.5 ppm, vertical 5mm +0.5 ppm; rtk accuracy: Horizontal 10mm +1 ppm, vertical 15mm +1 ppm; dgps accuracy: better than 25cm. It is worth mentioning is that which the receiver in February 2007 in Germany if the 2007 Industrial Design Award. Southern mapping gps receiver products are rtk s82, s86, Bluetooth static gps, and so on. Which s82 use of integrated design, integration gps antenna, uhf data link, oem motherboards, Bluetooth communication modules, lithium battery, the rtk positioning accuracy: Flat ± (2cm +1 ppm), Vertical ± (3cm +1 ppm); the static post-processing accuracy : Flat ± (5mm +0.5 ppm), vertical ± (10mm +1 ppm); single positioning accuracy: 1.5m (cep); code differential positioning accuracy: 0.45m (cep). ◆ Car gps ◆ similar car gps Also similar to car gps positioning mobile terminals, personal positioning device. gps satellite positioning due to location-based services through a third party, so to pay, ranging from months / years of service fee. All current gps positioning terminal, are not navigation. Because then the need to increase hardware and software, the cost increase. We saw on TV advertising vehicle gps, gps and the car is completely different. It is a gps navigation products, when the need to navigate, the first position, that is, the starting point of navigation, which is a real gps position is different, it can not transmit the location information to a third party and the holder of there, because the navigation instrument the lack of phone features. For example, you put navigation in the car, your friend borrowed the car drove off, the navigator can not send a message to you, that you can not find the vehicle location. So navigation is not targeted. You say I bought a navigation phone that okay, you think, you put in the car navigation phone, and now a stolen car, the phone call himself to you or third parties send messages? It is the need of people to operate. So now the navigation terminals are not targeting. Navigation terminal can navigate routes, so you do not get lost in a strange place, draw the line so that you reach your destination, tell you your current location, and the surrounding facilities. China has made in the gps be a great market. Which many companies are navigating. But there are in the industry to do gps positioning management. Follow a series of gps applications associated to the mathematics and algorithm design, and the gis system, map projection, coordinate system! As the satellite orbits, satellite clock errors exist, troposphere, ionosphere on the signals, as well as man-made sa protection policy, making the civilian gps positioning accuracy of only 100 meters. To improve accuracy, the general differential gps (dgps) technology, a base station (differential station) for gps observations using the known exact coordinates of base station, compared with the observations, to arrive at a revised number, and external release . After receipt of the revised number of receivers, and compare their own observations, eliminating most of the error, get a more accurate position. Experiments show that using differential gps (dgps), positioning accuracy can be increased to 5 meters. gps warning device early warning device by gps gps satellite gps coordinate early warning device to complete the _set_, such as during an electronic eye, and then related equipment under the electronic eye is the establishment of a coordinate, so that makes the data fitted with the warning device coordinates reach this point, the coordinate point is reached before the 300 meters will begin early warning, telling the electronic eye in front of gun owners, not speeding, so that an early warning role to play. With such accuracy the number of data points are related, mainly using satellite positioning to achieve. The veracity of the test machine Reporter beauty shop through the car to help a friend, pick the 4 so-called "gps early warning aircraft," through research and comparison test machine to confirm which is a counterfeit gps "electronic dog." And reached the following conclusions: a. gps warning devices: an early warning alarm one point, one-way warning; point alarm, undisturbed; warning more than 98% accuracy. Choose many kinds of music and voice, sound quality is better. b. false gps warning device: two with an early warning alarm point (towards the point and leave early warning early warning alarm points); will be affected by certain public facilities such as the tower interference false alarm; more than a false negative, inadequate low accuracy 70%; alarm music and voice a single, poor sound quality gpstar smart gps system Mainly consists of two parts, namely: the local monitoring center software management platform and remote gps smart vehicle terminal. Intelligent vehicle terminal remote gps vehicle location information, speed, trajectory and other data back to the monitoring center, monitoring center receives the data, analyzed immediately, compared to the other treatment, and the results are to two types of normal forms of information or warning messages displayed to the administrator, the administrator to decide whether to take the necessary measures for the target vehicle.
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gps Category
gps satellite receiver, many different types, depending on the model is divided into geodesic type, total station, regular type, hand-held, integrated; according to use into truck, ship type, on-board type, board type, spring-loading . Use classification by the receiver 1. Navigation type receiver This type of receiver is mainly used for moving vehicle navigation, it can give real-time vehicle location and speed. Such receivers generally use the c / a code pseudorange measurement, real-time positioning accuracy of single point lower, typically ± 25mm, when there sa of ± 100mm. Such receivers are cheap, widely used. According to different application areas, such receivers can be further divided into: Vehicle type - for vehicle navigation and positioning; Marine type - for ship navigation and positioning; Air-type - used in aircraft navigation and positioning. As the aircraft is fast, so in aviation requirements by the receiver can adapt to high-speed movement. Board type - for satellite navigation and positioning. As the speed of the satellite up 7km / s or more, and therefore require higher receiver. 2. Geodetic-type receivers Geodetic-type receivers is mainly used for precise measurement of geodetic and precision engineering. Such instrument is mainly carried out by carrier phase observations relative positioning, high positioning accuracy. Apparatus complex, more expensive. 3. Timing-type receiver The main advantage of this type of gps satellite receiver, high-precision time standards for timing, commonly used in the Observatory and radio communications in the time synchronization. 4.2.2 Classification of the carrier frequency by the receiver Single-frequency receiver L1 single-frequency receiver can only receive the carrier signal, measured values of carrier phase positioning. Can not effectively eliminate the impact of ionospheric delay, single-frequency receiver is only applicable to short baseline (<15km) of precise positioning. Dual-frequency receiver Dual-frequency receiver can receive both l1, l2 carrier signal. Frequency of using different ionospheric delay can eliminate the ionospheric delay on the impact of electromagnetic signals, it can be used for dual-band receiver for precise positioning of thousands of kilometers long. 4.2.3 Classification according to the number of receiver channels gps receiver gps satellites simultaneously receiving multiple satellite signals, in order to separate the received signals from different satellites to achieve the tracking of satellite signals, processing and measurement devices have such functions as the antenna signal path. According to the receiver by a channel can be divided into categories: Multi-channel receiver Sequential-channel receiver Multi-channel multi-channel receiver 4.2.4 Classification of works by the receiver Code dependent receiver Type of receiver is the use of code-related code-related technology has been pseudo-range observations. Square-type receiver Square-type receiver is the use of technology to remove the square of the carrier signal modulated signal to recover the complete determination of the carrier signal through the phase meter carrier signal generated by the receiver to the carrier signal and receiving the phase difference between the measured pseudo-range observations . Hybrid Receiver This instrument is a comprehensive advantages of the two receivers, both can get the code phase pseudorange, carrier phase can be observed values. Interferometric receiver The receiver is the gps satellites as radio sources, the use of interferometry to measure the distance between two stations. After 20 years of proven, gps system is a high precision, all-weather and global radio navigation, positioning and timing of the multi-functional system. gps technology has developed into a multi-area, multi-mode, multi-purpose, multi-model international high-tech industries. ◆ Type gps geodetic Geodetic-type receivers is mainly used for precise measurement of geodetic and precision engineering. Such instrument is mainly carried out by carrier phase observations relative positioning, high positioning accuracy. Apparatus complex, more expensive. Depending on use and accuracy, is divided into static (single frequency) receiver and dynamic (frequency) receiver that rtk. At present, gps technology development and practical application, the more well-known international manufacturer of the United States trimble (Tempo) navigation, Switzerland leica geosystems (Leica Geosystems), Japan topcon (TOPCON), the United States magellan (Magellan ) Company (formerly Thales Navigation), Shanghai Hua measured domestic navigation, the Haida and so on. trimble (Tempo) the geodesic-based gps receiver products are r8, r7, r6, and 5800,5700 and so on. Among them, the 5800 24 channel gps / waas / egnos receiver, it is the dual-band gps receiver, gps antenna, uhf radio and power supply are combined in a compact unit, with built-in trimble maxwell 4 Ultra chip tracking technology. Even in the harsh electromagnetic environment, is still less than 2.5 watts of power can be used to provide effective tracking of the satellite. Meanwhile, to expand the coverage and overall reduced operating errors, more than 5800 base stations to the same frequency manner. In addition, it trimble vrs network technology is fully compatible with its built-waas and egnos feature provides a non-real-time differential positioning base station. leica geosystems (Leica Geosystems) is the world's leading professional survey company, is a fast static and dynamic rtk pioneer. The gps1200 system receiver includes 4 models: gx1230 gg/atx1230 gg, gx1230/atx1230, gx1220 and gx1210. Which, gx1230 gg/atx1230 gg 72-channel, dual-rtk measuring receiver, receiver integrated radio, gsm, gprs and cdma module, with continuous checking (smartcheck +) function, waterproof (water 1m), dust, sand. Dynamic accuracy: Horizontal 10mm +1 ppm, vertical 20mm +1 ppm; static accuracy: Horizontal 5mm +0.5 ppm, vertical 10mm +0.5 ppm. Rtk when it 20hz to reach 30km or more away and can ensure the centimeter-level accuracy, the baseline the reliability of the 30 km is 99.99%. Japan topcon (Topcon) produced mainly gps receiver gr-3, gb-1000, hiper, net-g3 and so on. Which, gr-3 geodetic type receivers can be 100% compatible with the three major satellite systems (gps + glonass + galieo) of all available signals, there are 72 tracking channels, the use of anti-2 m drop rugged design, Bluetooth communications, the Home gsm / gprs module (optional). Static, rapid static accuracy: Horizontal 3mm +0.5 ppm, vertical 5mm +0.5 ppm; rtk accuracy: Horizontal 10mm +1 ppm, vertical 15mm +1 ppm; dgps accuracy: better than 25cm. It is worth mentioning is that which the receiver in February 2007 in Germany if the 2007 Industrial Design Award. Southern mapping gps receiver products are rtk s82, s86, Bluetooth static gps, and so on. Which s82 use of integrated design, integration gps antenna, uhf data link, oem motherboards, Bluetooth communication modules, lithium battery, the rtk positioning accuracy: Flat ± (2cm +1 ppm), Vertical ± (3cm +1 ppm); the static post-processing accuracy : Flat ± (5mm +0.5 ppm), vertical ± (10mm +1 ppm); single positioning accuracy: 1.5m (cep); code differential positioning accuracy: 0.45m (cep). Static (single frequency) receiver specifications Technical parameters Parallel 12-channel single frequency gps receiver l1 c / a code Fully integrated design - the host, antenna, power supply integrated Memory: 16m Accuracy Mode: static, rapid static Level: (5 +1 × 10-6d) mm Vertical: (10 +2 × 10-6d) mm Mode: After the treatment: stop and go, after dealing with dynamic, continuous Level: (10 +1 × 10-6d) mm Vertical: (20 +1 × 10-6d) mm Sample rate: 1hz Data update rate: 1hz Physical parameters Size: 6cm × 15cm (h * d) Weight: 0.8kg Environment Operating temperature: -30 ℃ ----+ 75 ℃ Storage temperature: -40 ℃ ----+ 85 ℃ Waterproof: 100% dustproof and waterproof, non-condensing Shock and vibration: 2m high resistance to fall Electrical Specifications Battery: Rechargeable lithium batteries Power: 0.8w Working Hours: 18 hours Data Interface: nmea0183, rtcm104 Digital Transmission Interface: standard rs-232 interfaces, usb interface, Bluetooth interface (optional) Dynamic (frequency) receiver / rtk Specifications Real-time dynamic (rtk) Level of accuracy of ± (10 + 1 × 10-6 × d) mm Vertical accuracy of ± (20 + 1 × 10-6 × d) mm Initialization time 10s Initialization reliability typically> 99.99% Code differential position (rtd) Level of accuracy of ± (0.25 + 1 × 10-6 × d) m Vertical accuracy of ± (0.25 + 1 × 10-6 × d) m Static and fast static Level of accuracy of ± (5 + 1 × 10-6 × d) mm Vertical accuracy of ± (10 + 2 × 10-6 × d) mm Data Format Export format hcn, dat, rinex Physical parameters Size (w × h) 200 × 85mm Weight 1.4kg Electrical parameters Host power 2.8w Battery 2200mah 10 hours battery life Battery life of 1000 charge-discharge process External power supply 10-18vdc Environment Operating temperature -40 ℃ - +75 ℃ Storage Temperature -50 ℃ - +85 ℃ 100% non-condensing humidity Water to meet the ipx7 provides 1 meter can be immersed in water, can float Resistance to shock and vibration can be dropped up to 3 meters Performance parameters Tracking l1, l2, l2c, l5 and galilo 28 channel parallel channel (upgradeable to 72 channels) Key / Display 2 key / 4led Show i / o rs232, usb, bluetooth Data link Power (vhf) 1w-20w can be adjusted as needed Distance of (vhf) 10-20km Bandwidth 220-240mhz/410-430mhz/450-470mhz Optional Distance ≥ 70km network rtk ◆ Car gps Car gps navigation 1) System Features mp3 player: Mp3 player can use music player, allowing users to get in the monotony of the journey adjust and relax. The network will be like the first music download to your computer, and then spread to the unit through a card reader mmc / sd card named "mp3" directory. Touch-screen handwriting input: Chinese characters in English letters and numbers to provide the handwriting input, making the query more convenient. Writing pen needle in the center of the screen, you can write in the input box displays the user's words, the choice of the system gives the input box lists options you can choose to enter the word. 2) System Configuration Operating System: microsoft windows ce. Net 4.2 E-map: voice navigation system, continent-wide navigation Microprocessor: intel pxa255 ╟ 300mhz Built-in memory: 32mb flash rom + 32mb sdram Display Screen: 3.5 "semi-transmissive tft display panel, led backlight, resolution 240x320 16 位, 65k color display, support qvga mode Satellite Navigation: Built-in GPS module with high sensitivity gps Antenna: Built-in satellite receiver antenna 25 x25 mm Button / Switch: power on / off; volume control wheel; 5 shortcut key (_set_ to return, destination, zoom in, zoom); 4 arrow keys + 1 implementation keys (up, down, left, right, implementation); hardware re_set_ switch; system re_set_ switch Audio Output: support for mp3 playback Input Output: touch pad (touch control panel); input mode (pen / handwriting recognition input); internal expansion slots (sd / mmc); speakers (a _set_ of built-in speakers); headphones (3.5mm mini external jack); data transmission lines (usb1.1 synchronous transmission) Rechargeable lithium battery: 1100mah rechargeable lithium battery; startup screen, no backlight sustainable gps feature 5 hours of work; start gps feature screen brightness of a display of sustainable operation 3 hours; standby time of up to 19 days Power adapter: input 100-240vac output 5vdc, 1a Operating temperature: 0 ~ 55 ℃ Annex: 256m mmc card, car antenna, car bracket, car suction cup, car charger ◆ similar car gps Also similar to car gps positioning mobile terminals, personal positioning device. gps satellite positioning due to location-based services through a third party, so to pay, ranging from months / years of service fee. All current gps positioning terminal, are not navigation. Because then the need to increase hardware and software, the cost increase. We saw on TV advertising vehicle gps, gps and the car is completely different. It is a gps navigation products, when the need to navigate, the first position, that is, the starting point of navigation, which is a real gps position is different, it can not transmit the location information to a third party and the holder of there, because the navigation instrument the lack of phone features. For example, you put navigation in the car, your friend borrowed the car drove off, the navigator can not send a message to you, that you can not find the vehicle location. So navigation is not targeted. You say I bought a navigation phone that okay, you think, you put in the car navigation phone, and now a stolen car, the phone call himself to you or third parties send messages? It is the need of people to operate. So now the navigation terminals are not targeting. Navigation terminal can navigate routes, so you do not get lost in a strange place, draw the line so that you reach your destination, tell you your current location, and the surrounding facilities. China has made in the gps be a great market. Which many companies are navigating. But there are in the industry to do gps positioning management. Follow a series of gps applications associated to the mathematics and algorithm design, and the gis system, map projection, coordinate system! As the satellite orbits, satellite clock errors exist, troposphere, ionosphere on the signals, as well as man-made sa protection policy, making the civilian gps positioning accuracy of only 100 meters. To improve accuracy, the general differential gps (dgps) technology, a base station (differential station) for gps observations using the known exact coordinates of base station, compared with the observations, to arrive at a revised number, and external release . After receipt of the revised number of receivers, and compare their own observations, eliminating most of the error, get a more accurate position. Experiments show that using differential gps (dgps), positioning accuracy can be increased to 5 meters. gps warning device early warning device by gps gps satellite gps coordinate early warning device to complete the _set_, such as during an electronic eye, and then related equipment under the electronic eye is the establishment of a coordinate, so that makes the data fitted with the warning device coordinates reach this point, the coordinate point is reached before the 300 meters will begin early warning, telling the electronic eye in front of gun owners, not speeding, so that an early warning role to play. With such accuracy the number of data points are related, mainly using satellite positioning to achieve. The veracity of the test machine Reporter beauty shop through the car to help a friend, pick the 4 so-called "gps early warning aircraft," through research and comparison test machine to confirm which is a counterfeit gps "electronic dog." And reached the following conclusions: a. gps warning devices: an early warning alarm one point, one-way warning; point alarm, undisturbed; warning more than 98% accuracy. Choose many kinds of music and voice, sound quality is better. b. false gps warning device: two with an early warning alarm point (towards the point and leave early warning early warning alarm points); will be affected by certain public facilities such as the tower interference false alarm; more than a false negative, inadequate low accuracy 70%; alarm music and voice a single, poor sound quality gpstar smart gps system Mainly consists of two parts, namely: the local monitoring center software management platform and remote gps smart vehicle terminal. Intelligent vehicle terminal remote gps vehicle location information, speed, trajectory and other data back to the monitoring center, monitoring center receives the data, analyzed immediately, compared to the other treatment, and the results are to two types of normal forms of information or warning messages displayed to the administrator, the administrator to decide whether to take the necessary measures for the target vehicle.
Translated by Google
gps Category
gps satellite receiver, many different types, depending on the model is divided into geodesic type, total station, regular type, hand-held, integrated; according to use into truck, ship type, on-board type, board type, spring-loading . Use classification by the receiver 1. Navigation type receiver This type of receiver is mainly used for moving vehicle navigation, it can give real-time vehicle location and speed. Such receivers generally use the c / a code pseudorange measurement, real-time positioning accuracy of single point lower, typically ± 25mm, when there sa of ± 100mm. Such receivers are cheap, widely used. According to different application areas, such receivers can be further divided into: Vehicle type - for vehicle navigation and positioning; Marine type - for ship navigation and positioning; Air-type - used in aircraft navigation and positioning. As the aircraft is fast, so in aviation requirements by the receiver can adapt to high-speed movement. Board type - for satellite navigation and positioning. As the speed of the satellite up 7km / s or more, and therefore require higher receiver. 2. Geodetic-type receivers Geodetic-type receivers is mainly used for precise measurement of geodetic and precision engineering. Such instrument is mainly carried out by carrier phase observations relative positioning, high positioning accuracy. Apparatus complex, more expensive. 3. Timing-type receiver The main advantage of this type of gps satellite receiver, high-precision time standards for timing, commonly used in the Observatory and radio communications in the time synchronization. 4.2.2 Classification of the carrier frequency by the receiver Single-frequency receiver L1 single-frequency receiver can only receive the carrier signal, measured values of carrier phase positioning. Can not effectively eliminate the impact of ionospheric delay, single-frequency receiver is only applicable to short baseline (<15km) of precise positioning. Dual-frequency receiver Dual-frequency receiver can receive both l1, l2 carrier signal. Frequency of using different ionospheric delay can eliminate the ionospheric delay on the impact of electromagnetic signals, it can be used for dual-band receiver for precise positioning of thousands of kilometers long. 4.2.3 Classification according to the number of receiver channels gps receiver gps satellites simultaneously receiving multiple satellite signals, in order to separate the received signals from different satellites to achieve the tracking of satellite signals, processing and measurement devices have such functions as the antenna signal path. According to the receiver by a channel can be divided into categories: Multi-channel receiver Sequential-channel receiver Multi-channel multi-channel receiver 4.2.4 Classification of works by the receiver Code dependent receiver Type of receiver is the use of code-related code-related technology has been pseudo-range observations. Square-type receiver Square-type receiver is the use of technology to remove the square of the carrier signal modulated signal to recover the complete determination of the carrier signal through the phase meter carrier signal generated by the receiver to the carrier signal and receiving the phase difference between the measured pseudo-range observations . Hybrid Receiver This instrument is a comprehensive advantages of the two receivers, both can get the code phase pseudorange, carrier phase can be observed values. Interferometric receiver The receiver is the gps satellites as radio sources, the use of interferometry to measure the distance between two stations. After 20 years of proven, gps system is a high precision, all-weather and global radio navigation, positioning and timing of the multi-functional system. gps technology has developed into a multi-area, multi-mode, multi-purpose, multi-model international high-tech industries. ◆ Type gps geodetic Geodetic-type receivers is mainly used for precise measurement of geodetic and precision engineering. Such instrument is mainly carried out by carrier phase observations relative positioning, high positioning accuracy. Apparatus complex, more expensive. Depending on use and accuracy, is divided into static (single frequency) receiver and dynamic (frequency) receiver that rtk. At present, gps technology development and practical application, the more well-known international manufacturer of the United States trimble (Tempo) navigation, Switzerland leica geosystems (Leica Geosystems), Japan topcon (TOPCON), the United States magellan (Magellan ) Company (formerly Thales Navigation), Shanghai Hua measured domestic navigation, the Haida and so on. trimble (Tempo) the geodesic-based gps receiver products are r8, r7, r6, and 5800,5700 and so on. Among them, the 5800 24 channel gps / waas / egnos receiver, it is the dual-band gps receiver, gps antenna, uhf radio and power supply are combined in a compact unit, with built-in trimble maxwell 4 Ultra chip tracking technology. Even in the harsh electromagnetic environment, is still less than 2.5 watts of power can be used to provide effective tracking of the satellite. Meanwhile, to expand the coverage and overall reduced operating errors, more than 5800 base stations to the same frequency manner. In addition, it trimble vrs network technology is fully compatible with its built-waas and egnos feature provides a non-real-time differential positioning base station. leica geosystems (Leica Geosystems) is the world's leading professional survey company, is a fast static and dynamic rtk pioneer. The gps1200 system receiver includes 4 models: gx1230 gg/atx1230 gg, gx1230/atx1230, gx1220 and gx1210. Which, gx1230 gg/atx1230 gg 72-channel, dual-rtk measuring receiver, receiver integrated radio, gsm, gprs and cdma module, with continuous checking (smartcheck +) function, waterproof (water 1m), dust, sand. Dynamic accuracy: Horizontal 10mm +1 ppm, vertical 20mm +1 ppm; static accuracy: Horizontal 5mm +0.5 ppm, vertical 10mm +0.5 ppm. Rtk when it 20hz to reach 30km or more away and can ensure the centimeter-level accuracy, the baseline the reliability of the 30 km is 99.99%. Japan topcon (Topcon) produced mainly gps receiver gr-3, gb-1000, hiper, net-g3 and so on. Which, gr-3 geodetic type receivers can be 100% compatible with the three major satellite systems (gps + glonass + galieo) of all available signals, there are 72 tracking channels, the use of anti-2 m drop rugged design, Bluetooth communications, the Home gsm / gprs module (optional). Static, rapid static accuracy: Horizontal 3mm +0.5 ppm, vertical 5mm +0.5 ppm; rtk accuracy: Horizontal 10mm +1 ppm, vertical 15mm +1 ppm; dgps accuracy: better than 25cm. It is worth mentioning is that which the receiver in February 2007 in Germany if the 2007 Industrial Design Award. Southern mapping gps receiver products are rtk s82, s86, Bluetooth static gps, and so on. Which s82 use of integrated design, integration gps antenna, uhf data link, oem motherboards, Bluetooth communication modules, lithium battery, the rtk positioning accuracy: Flat ± (2cm +1 ppm), Vertical ± (3cm +1 ppm); the static post-processing accuracy : Flat ± (5mm +0.5 ppm), vertical ± (10mm +1 ppm); single positioning accuracy: 1.5m (cep); code differential positioning accuracy: 0.45m (cep). Static (single frequency) receiver specifications Technical parameters Parallel 12-channel single frequency gps receiver l1 c / a code Fully integrated design - the host, antenna, power supply integrated Memory: 16m Accuracy Mode: static, rapid static Level: (5 +1 × 10-6d) mm Vertical: (10 +2 × 10-6d) mm Mode: After the treatment: stop and go, after dealing with dynamic, continuous Level: (10 +1 × 10-6d) mm Vertical: (20 +1 × 10-6d) mm Sample rate: 1hz Data update rate: 1hz Physical parameters Size: 6cm × 15cm (h * d) Weight: 0.8kg Environment Operating temperature: -30 ℃ ----+ 75 ℃ Storage temperature: -40 ℃ ----+ 85 ℃ Waterproof: 100% dustproof and waterproof, non-condensing Shock and vibration: 2m high resistance to fall Electrical Specifications Battery: Rechargeable lithium batteries Power: 0.8w Working Hours: 18 hours Data Interface: nmea0183, rtcm104 Digital Transmission Interface: standard rs-232 interfaces, usb interface, Bluetooth interface (optional) Dynamic (frequency) receiver / rtk Specifications Real-time dynamic (rtk) Level of accuracy of ± (10 + 1 × 10-6 × d) mm Vertical accuracy of ± (20 + 1 × 10-6 × d) mm Initialization time 10s Initialization reliability typically> 99.99% Code differential position (rtd) Level of accuracy of ± (0.25 + 1 × 10-6 × d) m Vertical accuracy of ± (0.25 + 1 × 10-6 × d) m Static and fast static Level of accuracy of ± (5 + 1 × 10-6 × d) mm Vertical accuracy of ± (10 + 2 × 10-6 × d) mm Data Format Export format hcn, dat, rinex Physical parameters Size (w × h) 200 × 85mm Weight 1.4kg Electrical parameters Host power 2.8w Battery 2200mah 10 hours battery life Battery life of 1000 charge-discharge process External power supply 10-18vdc Environment Operating temperature -40 ℃ - +75 ℃ Storage Temperature -50 ℃ - +85 ℃ 100% non-condensing humidity Water to meet the ipx7 provides 1 meter can be immersed in water, can float Resistance to shock and vibration can be dropped up to 3 meters Performance parameters Tracking l1, l2, l2c, l5 and galilo 28 channel parallel channel (upgradeable to 72 channels) Key / Display 2 key / 4led Show i / o rs232, usb, bluetooth Data link Power (vhf) 1w-20w can be adjusted as needed Distance of (vhf) 10-20km Bandwidth 220-240mhz/410-430mhz/450-470mhz Optional Distance ≥ 70km network rtk ◆ Car gps Car gps navigation 1) System Features mp3 player: Mp3 player can use music player, allowing users to get in the monotony of the journey adjust and relax. The network will be like the first music download to your computer, and then spread to the unit through a card reader mmc / sd card named "mp3" directory. Touch-screen handwriting input: Chinese characters in English letters and numbers to provide the handwriting input, making the query more convenient. Writing pen needle in the center of the screen, you can write in the input box displays the user's words, the choice of the system gives the input box lists options you can choose to enter the word. 2) System Configuration Operating System: microsoft windows ce. Net 4.2 E-map: voice navigation system, continent-wide navigation Microprocessor: intel pxa255 ╟ 300mhz Built-in memory: 32mb flash rom + 32mb sdram Display Screen: 3.5 "semi-transmissive tft display panel, led backlight, resolution 240x320 16 位, 65k color display, support qvga mode Satellite Navigation: Built-in GPS module with high sensitivity gps Antenna: Built-in satellite receiver antenna 25 x25 mm Button / Switch: power on / off; volume control wheel; 5 shortcut key (_set_ to return, destination, zoom in, zoom); 4 arrow keys + 1 implementation keys (up, down, left, right, implementation); hardware re_set_ switch; system re_set_ switch Audio Output: support for mp3 playback Input Output: touch pad (touch control panel); input mode (pen / handwriting recognition input); internal expansion slots (sd / mmc); speakers (a _set_ of built-in speakers); headphones (3.5mm mini external jack); data transmission lines (usb1.1 synchronous transmission) Rechargeable lithium battery: 1100mah rechargeable lithium battery; startup screen, no backlight sustainable gps feature 5 hours of work; start gps feature screen brightness of a display of sustainable operation 3 hours; standby time of up to 19 days Power adapter: input 100-240vac output 5vdc, 1a Operating temperature: 0 ~ 55 ℃ Annex: 256m mmc card, car antenna, car bracket, car suction cup, car charger ◆ similar car gps Also similar to car gps positioning mobile terminals, personal positioning device. gps satellite positioning due to location-based services through a third party, so to pay, ranging from months / years of service fee. All current gps positioning terminal, are not navigation. Because then the need to increase hardware and software, the cost increase. We saw on TV advertising vehicle gps, gps and the car is completely different. It is a gps navigation products, when the need to navigate, the first position, that is, the starting point of navigation, which is a real gps position is different, it can not transmit the location information to a third party and the holder of there, because the navigation instrument the lack of phone features. For example, you put navigation in the car, your friend borrowed the car drove off, the navigator can not send a message to you, that you can not find the vehicle location. So navigation is not targeted. You say I bought a navigation phone that okay, you think, you put in the car navigation phone, and now a stolen car, the phone call himself to you or third parties send messages? It is the need of people to operate. So now the navigation terminals are not targeting. Navigation terminal can navigate routes, so you do not get lost in a strange place, draw the line so that you reach your destination, tell you your current location, and the surrounding facilities. China has made in the gps be a great market. Which many companies are navigating. But there are in the industry to do gps positioning management. Follow a series of gps applications associated to the mathematics and algorithm design, and the gis system, map projection, coordinate system! As the satellite orbits, satellite clock errors exist, troposphere, ionosphere on the signals, as well as man-made sa protection policy, making the civilian gps positioning accuracy of only 100 meters. To improve accuracy, the general differential gps (dgps) technology, a base station (differential station) for gps observations using the known exact coordinates of base station, compared with the observations, to arrive at a revised number, and external release . After receipt of the revised number of receivers, and compare their own observations, eliminating most of the error, get a more accurate position. Experiments show that using differential gps (dgps), positioning accuracy can be increased to 5 meters. gps warning device early warning device by gps gps satellite gps coordinate early warning device to complete the _set_, such as during an electronic eye, and then related equipment under the electronic eye is the establishment of a coordinate, so that makes the data fitted with the warning device coordinates reach this point, the coordinate point is reached before the 300 meters will begin early warning, telling the electronic eye in front of gun owners, not speeding, so that an early warning role to play. With such accuracy the number of data points are related, mainly using satellite positioning to achieve. gpstar smart gps system Mainly consists of two parts, namely: the local monitoring center software management platform and remote gps smart vehicle terminal. Intelligent vehicle terminal remote gps vehicle location information, speed, trajectory and other data back to the monitoring center, monitoring center receives the data, analyzed immediately, compared to the other treatment, and the results are to two types of normal forms of information or warning messages displayed to the administrator, the administrator to decide whether to take the necessary measures for the target vehicle.
Translated by Google
gps principle
gps navigation system, the basic principle is to measure the known location of the satellite to the user the distance between the receiver and then integrated multi-satellite data can know the exact location of the receiver. To achieve this, the satellite's position can be recorded under the satellite clock time, check out the satellite ephemeris. The distance between the satellite and the user to record the satellite signal propagation through the elapsed time to the user, and then multiplied by the speed of light received (due to the interference of the atmosphere ionosphere, the distance between the satellite and the user is not the real distance, but pseudo-range (pr): When the gps satellites work, it will continue to use 1 and 0 symbol composed of binary pseudo-random code (referred to as pseudo-code) launch the navigation message. gps systems use pseudo-code, a total of two, namely civilian c / a code and military p (y) code. c / a code frequency 1.023mhz, repeat the cycle of a millisecond, the code distance between 1 microsecond, the equivalent of 300m; p code frequency 10.23mhz, repeat the cycle of 266.4 days, code distance of 0.1 microseconds, equivalent to 30m. The code is in the p y formed on the basis code, confidential performance better. navigation data including satellite ephemeris, work status, clock corrections, ionospheric delay correction, atmospheric refraction correction and other information. It is the demodulation signal from the satellite out to 50b / s modulation in the carrier frequency emitted. navigation message included in each of the main frame 5 sub-frames per frame size 6s. the first three frames of the 10 code; repeated every thirty seconds, updated hourly. After the two were 15000b. navigation message in the main content of telemetry codes, code conversion, the first data blocks 1,2,3, including the most important was ephemeris data. When the user receives the navigation message, the extraction time and the satellite clock to do their comparison with their satellite and the user will be aware of the distance, and then use the satellite navigation message ephemeris data message when the projected location of the satellite launch , users wgs-84 geodetic coordinate system position, velocity and other information will be known. Gps satellite navigation system can be seen part of the role is to continue to launch the navigation message. However, the user receiver clock with the satellite using the satellite clock can not always synchronized, so in addition to the user's three-dimensional coordinates x, y, z, but also the introduction of a satellite and receiver Δt is the time difference between the as unknown, Then four equations out of these four unknown solutions. So if you want to know the location of the receiver, at least 4 months to be able to receive satellite signals.
Translated by Google
gps Category
gps satellite receiver, many different types, depending on the model is divided into geodesic type, total station, regular type, hand-held, integrated; according to use into truck, ship type, on-board type, board type, spring-loading . After 20 years of proven, gps system is a high precision, all-weather and global radio navigation, positioning and timing of the multi-functional system. gps technology has developed into a multi-area, multi-mode, multi-purpose, multi-model international high-tech industries. ◆ Car gps Car gps navigation 1) System Features mp3 player: Mp3 player can use music player, allowing users to get in the monotony of the journey adjust and relax. The network will be like the first music download to your computer, and then spread to the unit through a card reader mmc / sd card named "mp3" directory. Touch-screen handwriting input: Chinese characters in English letters and numbers to provide the handwriting input, making the query more convenient. Writing pen needle in the center of the screen, you can write in the input box displays the user's words, the choice of the system gives the input box lists options you can choose to enter the word. 2) System Configuration Operating System: microsoft windows ce. Net 4.2 E-map: voice navigation system, continent-wide navigation Microprocessor: intel pxa255 ╟ 300mhz Built-in memory: 32mb flash rom + 32mb sdram Display Screen: 3.5 "semi-transmissive tft display panel, led backlight, resolution 240x320 16 位, 65k color display, support qvga mode Satellite Navigation: Built-in GPS module with high sensitivity gps Antenna: Built-in satellite receiver antenna 25 x25 mm Button / Switch: power on / off; volume control wheel; 5 shortcut key (_set_ to return, destination, zoom in, zoom); 4 arrow keys + 1 implementation keys (up, down, left, right, implementation); hardware re_set_ switch; system re_set_ switch Audio Output: support for mp3 playback Input Output: touch pad (touch control panel); input mode (pen / handwriting recognition input); internal expansion slots (sd / mmc); speakers (a _set_ of built-in speakers); headphones (3.5mm mini external jack); data transmission lines (usb1.1 synchronous transmission) Rechargeable lithium battery: 1100mah rechargeable lithium battery; startup screen, no backlight sustainable gps feature 5 hours of work; start gps feature screen brightness of a display of sustainable operation 3 hours; standby time of up to 19 days Power adapter: input 100-240vac output 5vdc, 1a Operating temperature: 0 ~ 55 ℃ Annex: 256m mmc card, car antenna, car bracket, car suction cup, car charger ◆ similar car gps Also similar to car gps positioning mobile terminals, personal positioning device. gps satellite positioning due to location-based services through a third party, so to pay, ranging from months / years of service fee. All current gps positioning terminal, are not navigation. Because then the need to increase hardware and software, the cost increase. We saw on TV advertising vehicle gps, gps and the car is completely different. It is a gps navigation products, when the need to navigate, the first position, that is, the starting point of navigation, which is a real gps position is different, it can not transmit the location information to a third party and the holder of there, because the navigation instrument the lack of phone features. For example, you put navigation in the car, your friend borrowed the car drove off, the navigator can not send a message to you, that you can not find the vehicle location. So navigation is not targeted. You say I bought a navigation phone that okay, you think, you put in the car navigation phone, and now a stolen car, the phone call himself to you or third parties send messages? It is the need of people to operate. So now the navigation terminals are not targeting. Navigation terminal can navigate routes, so you do not get lost in a strange place, draw the line so that you reach your destination, tell you your current location, and the surrounding facilities. China has made in the gps be a great market. Which many companies are navigating. But there are in the industry to do gps positioning management. Follow a series of gps applications associated to the mathematics and algorithm design, and the gis system, map projection, coordinate system! As the satellite orbits, satellite clock errors exist, troposphere, ionosphere on the signals, as well as man-made sa protection policy, making the civilian gps positioning accuracy of only 100 meters. To improve accuracy, the general differential gps (dgps) technology, a base station (differential station) for gps observations using the known exact coordinates of base station, compared with the observations, to arrive at a revised number, and external release . After receipt of the revised number of receivers, and compare their own observations, eliminating most of the error, get a more accurate position. Experiments show that using differential gps (dgps), positioning accuracy can be increased to 5 meters. gps warning device early warning device by gps gps satellite gps coordinate early warning device to complete the _set_, such as during an electronic eye, and then related equipment under the electronic eye is the establishment of a coordinate, so that makes the data fitted with the warning device coordinates reach this point, the coordinate point is reached before the 300 meters will begin early warning, telling the electronic eye in front of gun owners, not speeding, so that an early warning role to play. With such accuracy the number of data points are related, mainly using satellite positioning to achieve. gpstar smart gps system Mainly consists of two parts, namely: the local monitoring center software management platform and remote gps smart vehicle terminal. Intelligent vehicle terminal remote gps vehicle location information, speed, trajectory and other data back to the monitoring center, monitoring center receives the data, analyzed immediately, compared to the other treatment, and the results are to two types of normal forms of information or warning messages displayed to the administrator, the administrator to decide whether to take the necessary measures for the target vehicle.
Translated by Google
GPS stands for:
When the satellite measurements ranging Navigation / Global Positioning System Navigation Satellite Time and Ranging / Global Positioning System
Translated by Google
GPS form
gps GPS构成
gps GPS构成
gps GPS构成
1. Space segment GPS space segment is composed of 24 operating satellites, which is located above the 20 200km Jude Biao, evenly distributed in six orbital planes (each orbital plane 4), orbital inclination of 55 °. In addition, there are four active spare satellites in orbit. Makes the distribution of satellite anywhere in the world, any time can be observed in more than four satellites, and stored in the satellite navigation information can also be used for some time, but the navigation accuracy will be gradually reduced. 2. Ground Control System Ground control system consists of monitoring stations (Monitor Station), the main controller (Master Monitor Station), ground antennas (Ground Antenna) composed the main control station in Colorado, USA Springfield (Colorado Spring). Ground control station is responsible for collecting the information returned by the satellite and the satellite ephemeris calculation, the relative distance, atmospheric correction data. 3. User segment Part of the GPS user equipment signals receivers. Its main function is to capture a certain cut-off angle of the _select_ed satellite satellite under test and track the satellite operation. When the receiver to capture satellite signals to track, you can measure the pseudo-receiver antenna to satellite distance and the distance rate of change, demodulate the satellite orbital parameters and other data. Based on these data, the receiver of the micro-processing computer solution method can be carried out by targeting position calculation to calculate the latitude and longitude of the user geographic location, altitude, speed, time and other information. Inside the receiver hardware and software, and GPS data post-processing software package to provide a complete GPS user equipment. GPS receiver and receiving antenna elements structural unit is divided into two parts. Receivers generally use both inside and outside the aircraft DC power supply. The purpose of _set_ting the machine is to replace the external power supply when the power is not interrupted continuous observation. Time with the outside power in the battery automatically charges. Turned off, the machine battery powered RAM memory to prevent data loss. At present various types of receivers become smaller, more light weight, easy to use field observations. Followed by the user receiver, the existing single-frequency and dual-band two, but because of price factors, the multi-user purchased a single-frequency receiver.
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GPS Terminology
1.GPS Generalized Processor Sharing General processor sharing 2.GPS Global Positioning System Global Positioning Satellite / System 3. [GPSS] General Purpose Systems Simulator General system simulator 4. [DGPS] Differential GPS Differential GPS, differential global positioning system
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GPS Features
The main features of the Global Positioning System: (1) global, all-weather work. ① high positioning accuracy. Click the positioning accuracy of better than 10m, using differential positioning accuracy up to centimeters and millimeters. ② multi-function, wide application. GPS system features: high precision, all-weather, high efficiency, multi-functional, simple, widely used and so on. 1, high positioning accuracy Application Practice has proved that, GPS relative positioning accuracy of up to 50KM or less up to 10-6,100-500 KM 10-7,1000 KM up to 10-9. In the 300-1500M engineering precision positioning, the 1 hour observation plane, the planar solution of the position error is less than 1mm, with the ME-5000 was measured wave range finder side comparison, the largest of its lower side is 0.5mm, the school difference in error is 0.3mm. 2, the observation time is short With the GPS system of continuous improvement, the software constantly updated, current, 20KM within a relatively static position, only 15-20 minutes; fast static relative positioning measurements, when the distance of each rover and base station within the 15KM, the flow Station observation time just 1-2 minutes, then at any time position, only a few seconds of each station observation.
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GPS Applications
Mainly for ships, automobiles, aircraft navigation and other sports objects. For example: 1. The ship into port navigation and ocean water 2. Aircraft landing approach route guidance and 3. Vehicle autonomous navigation 4. Ground vehicle tracking and Urban Intelligent Traffic Management 5. Emergency rescue 6. Personal travel and outdoor adventure 7. Personal communication terminals (with the cell phone, PDA, electronic maps integrated into) 1. Electricity, telecommunications, communications and other network time synchronization 2. Exact time of the grant into 3. Accurate feedback into the frequency 1. Various grades of land measurement, control measurements 2. Lofting road and various line 3. Underwater topographic survey 4. Crustal deformation measurement, deformation monitoring of dams and large buildings 5.GIS Application 6. Construction Machinery (tire cranes, bulldozers, etc.) control 7. Precision Agriculture ◆ GPS application in road engineering ◆ GPS in car navigation and traffic management of Three-dimensional navigation is the primary function of GPS, aircraft, ships, ground vehicles and pedestrians can navigate using GPS navigator. Car Navigation System GPS Global Positioning System is developed on the basis of a new GPS application technology. Car navigation system consists of GPS, self-navigation, microprocessor, speed sensors, gyro sensors, CD-ROM drive, LCD display component. GPS navigation system with electronic map, radio communication networks, computer vehicle management information systems, can achieve vehicle tracking and traffic management, and many other features. ◆ GPS in the long-distance passenger transport vehicle management application (for example) The first _set_ of professional domestic long-distance passenger vehicle GPS System - GPS Ya fast long-distance passenger intelligent management system, for example, it is a combination of satellite positioning technology, GPRS / CDMA communication services, GIS technology, image acquisition technology, computer network and database technology, the bus company to establish a total control (C / S structure and the B / S structure combined), the other _set_ point control, the public security department and transportation management department and other departments to establish exclusive control of the central system, the system by the control center systems, wireless communication platform (GPRS / CDMA), global positioning system (GPS), vehicle equipment, a four-part all-weather, full range of driver management and vehicle tracking integrated platform; system dynamic tracking of registered vehicles, monitoring , taking pictures, driving records, management, data analysis and other functions, monitor the vehicle can be displayed on the electronic map, and keep the vehicle trajectory data; operating terminal can choose the server internal LAN or Internet access to the center and through IE browser Bus provides integrated management of online data analysis control system (B / S structure); and the system software at any time based on its capacity and operation of a central server hardware configuration of the terminal expansion, a maximum of five hundred thousand, network traffic can be a long-distance passenger vehicles only can also coaches and other social vehicles. At the same time the system can also use group management, different types of vehicles into different groups for easy management of the operation. GPS navigation instrument in the application example GPS navigation systems leading brands: Ahada (AI flight over) - from the Silicon Valley, now go to the China! Product core functions: 1) Map search ◎ You can search for operating the terminal destination location you want to go. ◎ can record where you always go to the location information, and retained, and can also share the location information with others. ◎ accessories or fuzzy queries to a location near you, such as gas stations, hotels, ATM machines and other information, 2) route planning ◎ GPS navigation system will be _set_ according to your starting point and destination, automatic planning of a line. ◎ planning line can _set_ whether to go through in some way point. ◎ planning is to avoid high-speed line can be _set_ to function. 3) automatic navigation ◎ voice navigation: Using voice to give motorists advance intersection turn driving navigation system status information, like a guide to show you understand the way how to drive to the same destination. The most important navigation functions, so that you do not need to watch the operation of the terminal, through the voice prompts to reach their destinations safely. ◎ screen navigation: Operating the terminal will display maps, and vehicle position, speed, destination, distance, route planning tips, turn indicator of the traffic information. ◎ re-planning of routes: When you do not have the line running by the planning, or when the wrong intersection, GPS navigation system will be based on your current location, for your re-planning of a new destination line.
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GPS in the new century
In the 21st century, the global positioning system (GPS) applications in all areas will be strengthened and developed. In this paper, GPS to the latest development in the 21st century, particularly the international GPS service (1GS) product content, applications and services and so on for the highlights. A, GPS stations network and continuous operation of the development of integrated service system Continuous operation in the global GPS ground stations (about 200) formed on the basis of the IGS (International GPS Service), is the continuous operation of GPS stations network and comprehensive service system example. It is free to provide GPS users around the world all kinds of information, such as the GPS precise ephemeris, rapid ephemeris, ephemeris, IGS station coordinates and velocities, IGS stations receive GPS signal phase and pseudorange data, the Earth's rotation rate and so on. The information in geodesy and geodynamics to support the numerous scientific projects, including the ionosphere, meteorology, reference frame, precision time transfer, high-resolution Earth rotation rate and the projected changes, crustal movements and so on. (1) IGS orbit now offers three types: First final (precise) orbit, to get it in 10-12 days later, commonly used in precision positioning; Second, Express Track, after 1 day to get in, it can be used in the atmosphere water vapor content, ionosphere calculation; there is a category is forecast track. With regard to the GPS satellite clock error estimates, there are only two IGS analysis centers. IGS is currently nearly 200 permanent continuous operation of the global tracking station, the use of an external frequency standard 70, of which about 30 minutes to use hydrogen, using the cesium atomic clock about 20, about 20 use the rubidium atomic clock, and the rest use the internal GPS crystal oscillator. (3) IGS provides a very useful and important information is the continuous operation of those IGS station (tracking station) coordinates, the corresponding frame, epoch and station speed. The former is better than the accuracy 1cm, which accuracy is better than 1mm / y. IGS station coordinates the coordinates used and the IERS reference frame is the co-ordination. The end of 1993 to start using ITRF91, 1994 annual use ITRF92, 1995 to 1996 by mid-ITRF93, 1996 to mid-April 1998 has been using ITRF94, 1998 年 3 月 1 日 turned to ITRF96, 1999 年 8 月 1 start IGS using ITRF97. (4) IGS nutation terms in the determination of the new short-term contributions. As we all know, the Earth's rotation axis moves in the Earth's surface is called polar motion, and it is the movement in inertial space is called precession and nutation. GPS technology can not determine the UT, but can only determine the length of day. This principle also applies to the same nutation, that GPS data can not determine the longitude and nutation angle, but it can determine the amount of time rate of change (for the time derivative.) Based on this principle, with a 3-year daily data ψ and ε values, the estimated short-term nutation nutation amplitudes, and results are compared with VLBI. Concluded that short-period nutation on the determination of item, GPS is superior to VLBI, while more than 1 month in terms of long-period, VLBI is better. Because of the IGS GPS technology has made such a great success and contributions, so in September 1999 VLBI stations and national decision also resemble the SLR stations corresponding IVS and IGS IVRS. France and Germany PRARE DORIS is also considering _set_ting up a similar pattern of international organizations. Strive to make this type of space geodetic observing systems to organize themselves, improve efficiency, increase accuracy and reliability. For regional GPS network for continuous operation and integrated service system, the developed countries have done a lot of work in this area, progress has been made. In the United States laid the GPS "Continuously Operating Reference Station" (CORS) system. It consists of the United States Geodetic Survey (NGS) is responsible for the system's current goal is to (1) to all users throughout the United States can be more convenient to use it to achieve centimeter level positioning and navigation; (2) to promote the user to use CORS the development of GIS; (3) monitoring of crustal deformation; ④ seeking distribution of water vapor given; ⑤ monitoring the concentration of free electrons in the ionosphere and distribution. CORS ended September 1999 had 156 points, while the U.S. announced that in order to strengthen NGS CORS system, from now on, the monthly rate of increase of 3 points to improve the spatial coverage of the system. In addition, CORS data and information including the received pseudorange and phase information, station coordinates, station mobile rate vector, GPS Star gas stations around the meteorological data, the user can through information networks such as the Internet is very easy to download and get. Britain established the "continuous operation of GPS reference station" (COGPS) system functions and goals similar to the CORS, but the combination of United Kingdom to monitor the situation more than a relative sea level around the British Isles and the absolute change in the task. UK COGPS by the Survey and Mapping Bureau, the Environmental Protection Agency, Bureau of Meteorology, Ministry of Agriculture, Marine Laboratory jointly responsible. At present nearly 30 months continuous operation of GPS stations, the future plans is the expansion of COGPS system and the establishment of a center, whose main task is to transfer, delivery, archiving, processing and analysis of GPS data in each station. Japan has built nearly 1,200 continuous operation of GPS stations network of integrated services system. It is now in order to monitor crustal deformation, earthquake prediction on the basis of the main features, combined with meteorological and atmospheric sectors GPS atmospheric science services. Second, GPS monitoring applied to the ionosphere GPS in monitoring the application of the ionosphere, but also the beginning of GPS space meteorology. Space filled with plasma, cosmic ray particles, various bands of electromagnetic radiation, the solar constant at 1 million tons of the order of seconds to throw the charged property, thus subject to strong ionospheric disturbances, which is space meteorology an object of study. By measuring the ionospheric delay on GPS signals to determine the total unit volume in the free electron content (TEC), to create a digital model of the global ionosphere. L1 GPS satellite launches and L2. The two carriers. By the two carriers to reduce ionospheric effects on GPS positioning, or you can find given ionospheric refraction. Because of the refraction and the carrier frequency. When people create regional or global digital model of the ionosphere, always make simplifying assumptions, all of the free electron concentrations are expressed in a single plane, the height from the ground surface H. In this case, electronic content is to be used in the receiver and the satellite connection in person with this single point (piercing point) at Es said electronic content, it can be regarded as E and the piercing point zenith distance Z 'the function of Ecos Z '= Es. Can be in the sphere to model the electron density Es, for example, latitude and longitude written in spherical harmonic functions, etc., which have many experts in various models. IGS ionospheric maps of a proposed interchange format (10nosphere Map Exchange Format, IONEX-Format), its role is to make all kinds of theories and technologies based on the ionospheric maps can be obtained in a unified standard based on a comprehensive and comparative . Ionospheric models have different theoretical basis of data obtained from the technology, the data coverage is not complete, it can only be a variety of IGS and global TEC maps and GPS satellite signals of the differential code bias (differential code biases-DCBS) form with IONEX offer to the world, the next step will compare step by step together. Third, GPS monitoring applied to the troposphere GPS used in the study of the troposphere, IGS Rapid orbit and orbital information for weather forecasting will play a significant role. In addition, IGS GFZ by Germany's "IGS troposphere comparison and coordination center" provided every 2 hours in the troposphere zenith delay series is like a control point, for regional or local study the troposphere, the tropospheric delay can play an absolute Calibration of the role of values. Different atmospheric monitoring and ground GPS, satellite-based or space-based GPS radio occultation method for the determination of meteorological technology has wide coverage, vertical resolution is good, the advantages of faster data acquisition. The principle of this technology is the GPS receiver on a LEO satellite (LEO) or aircraft platforms, the GPS receiver on the one hand to play the satellite (or aircraft) Precise Orbit Determination of the role, while applications GPS occultation technique to play the role of atmospheric probe. In 1997 the GPS / MET research project, confirmed the idea is feasible. Scheduled for April 2000 launch of the CHAMP satellite GPS radio occultation method to take advantage of the global tropospheric refraction (including atmospheric precipitation points) were determined. In the coming years, as well as Argentina's SAC-C, China Taiwan, COS-MIC, the LEO satellites to be used for satellite orbit determination and GPS to measure the atmosphere using radio occultation method. Future use of meteorological satellite and the GPS section of electron density values, combined with GPS ground station data, made available layer off the image to use. The next 3 years, GPS / MET project research is to be 6 times, which is expected in weather forecasting, space weather forecasting, weather monitoring has made great contributions. Fourth, GPS as the application of satellite altimeter
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Demand from the electronic map to see the development of GPS navigation products
As China accelerated the pace of urban construction and reconstruction, urban roads constantly new, complex and even spawned a number of road traffic in guiding the industry. New office buildings and hotels, the new asphalt paved road for some familiar place had become strange and stretches of urban roads, different patterns of the overpass, making the city's residents are often forced to go see the map. Data show that annual sales of Beijing Book Building, the top three in the list must have a map. Handheld GPS navigation products will enter a rapid development period On the precise destination and check the surrounding environment of the GPS navigation products, demand-driven market boom. According to statistics, Europe and the United States reached 90% penetration rate of navigation equipment, Japan is more than 95%. One pair of 3G applications and creative vision of the professional survey, 17.79% of the respondents chose the 3G network video dialogue, 15.34% of the respondents chose the GPS / Map search in the 3G era, people on the GPS / Electronic Map concern, enough to show its importance in daily life. In addition, consumer and market demand also contributed to the development and navigation industry to mature. In 2005, car ownership in China's civil reached 31.6 million, but the vehicle carrying the navigation device, less than 2%. Although many high-end models of its car manufacturers to install in the factory navigation system, on the other low-end models will have optional navigation products, services, but expensive car navigation systems (GPS optional Corolla A piece on the value of 1.5 million, and then mount prices are 7,000 yuan) to buy a car who gave up a lot of very practical navigation configuration. According to average annual growth rate of private car ownership of 20% is estimated that the demand for navigation products is a big increment. In Japan, car navigation market penetration of 0.4% from 1992 to 2000 to 33% penetration rate, currently 50%. European car navigation market, the market started later than in Japan, to 2004, the car navigation market penetration has reached 12%. If the Chinese car navigation market development rhythm similar to Japan and the EU market, car navigation systems market penetration to reach 10% in 2009, and the development of handheld navigation device market much faster than car navigation systems market. Therefore, analysts believe that armed Navigator will be as MP3, digital camera and other daily consumer electronics, the market's growth rate will be much faster than car navigation systems market, China will eventually become the world's largest consumer of handheld navigation products. GPS navigation products beneficial to improve the status of e-map market chaos Map search industry in China is still a government regulation, especially in the latest National Mapping Bureau, 2007 "Map of regulations", the mapping of the issued license and operating license to make electronic maps is limited. That is the map search operations to be scrutinized by the government. Currently, the Internet environment, the market order is chaotic map, 99% of illegal Internet map existing problems. GPS navigation systems on the market a large proportion of low-quality products, and costs are very low, the market price'd ridiculously high, the price is very opaque. Navigation systems on the market today several types of
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GPS navigation market development in China
China's huge market potential for GPS navigation. As of the end of 2005, China has a car navigation device for vehicles less than 10 million units, compared to 30 million of the total number of vehicles, the penetration rate of less than 1%. The Japanese car vehicle navigation installation rate as high as 59%, Europe about 25%. Portable navigation market in 2006 should have a size of nearly 5 million, and with the rapid market developments and emerging new brand, expected in 2009 China's auto GPS navigation system terminal will be close to 100 billion in sales. About the past 2008 years, known as China's "3G first year." As we all know, in the domestic communications, the fire is being test run in the TD-SCDMA - 3G standards. As a new generation of communication technology, 3G brought people a lot of expectations. Full payment of 3G licenses, but also have become a focus of common concern. In fact, the GPS navigation field in the country is also undergoing a transformation, the third generation came into being PND class navigation products, has put people into a new era of navigation. Satellite navigation industry in national economy is playing an increasingly important role, will be the Eleventh Five-Year "development of the bright spots. In the" Eleventh Five-Year "period, the satellite navigation in other areas such as air, sea, rail, construction, telecommunications, , electricity and other applications will have great development space. The trend of satellite navigation technology mainly in three aspects: First, the coexistence of multiple systems of satellite navigation, so that system availability is increased, the applications will be more extensive; the second is a multi-navigation technology is used widely, there are GPS and mobile communication base station location, top, dead reckoning, a combination of technology applications; Third, satellite navigation and wireless communications, and other high-tech combination, such as the GPS receiver embedded into cell phones, portable PC, PDA and watches and other communications, safety and consumer electronic products, and fundamentally promote the overall development of IT technology. GPS How to buy First, excellent quality, complete certification, safety first In the choice of GPS navigation products, the software and hardware configuration is very important. In general the hardware configuration of professional brands are more trustworthy. Some of the GPS manufacturers often lie cottage hardware configuration, the LCD screen, GPS chips, processors and so difficult to guarantee product quality. Their entire production process of GPS products is nothing more than some of the simple hardware integration and assembly. The hardware configuration of the regular GPS manufacturers often have to go through checks at each level and quality of production standards through ISO (ISO2000 quality certification mainly, ISO14001 environmental certification) and other certification. For automotive products only through the "ISO / TS TS16949 certification standards" in order to Mercedes-Benz, Volkswagen and other auto manufacturers supply products and services. Second, the software is easy to use, accurate data rich, additional features more Most attention in the software is GPS navigation map of the natural data accuracy and timeliness of updates. Regularly updated maps created electronic maps of high production costs, many GPS manufacturers would fail to reduce piracy map updates and other electronic map. If consumers use a "fake" navigation map of the machine is not only easy to "go astray" and even be fatal. Third, the brand of excellence, sale secure and trustworthy In fact, far more important than the brand the other. As the satellite navigation industry in China is a in the development of the high-tech industry, only those in the market, hard years of professional firms in order to protect the product technology leadership, but also have money and power to provide users with comprehensive, quality service guarantee . Product prices and purchase products after-sales service is the main factor to be considered. Consumers want to buy quality and cheap products, but the results may not be very rewarding. Now many of the navigation products market, "cheap" is not "poor quality." So, here to remind consumers to buy products, do not be deceived by low prices alone are not normal eyes. For drivers with their own travel, adventure travel is closely related to the navigation products, must not mean for their "travel safe" foot the bill. As a GPS navigation products, product technology upgrades and updates the map data is very important, only the professional manufacturers of brand to consumers in a timely manner to be able to provide this service. GPS technology in the future Highway Survey 3S technology industry based on four different areas of application system software For example: R & D based on the mobile 3S Swiss star from the source of forest resources at the own handheld survey system GPS navigation functions, but also has (1) system can be any of a variety of remote sensing image loading, scanning Topographic maps, vector and can automatically take the traditional side, smart thumbnail generation. (2) Resources from the property database Definition, the definition of point, line and plane layer management. (3) area measurement accuracy, two points from precision measurements. (4) Small experimental editing. (5) high-precision field measurement points and the registration. (6) a variety of coordinate transformation, a variety of number According to format conversion. Full realization of paperless and automated resource surveys.
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GPS tracker in the car of
Use of global navigation system GPS, you can receive satellite signals to determine the ground position in due course. GSM wireless network through modern technology, the GPS position to determine the ground position is passed to a number of professional platform and the platform mark the current location. Users can easily use this method to get the target position. GPS tracker in the car application, has been applied to all aspects of life in the police investigations, GPS vehicle tracking device is an integral part of the decision of the police will put GPS locator tool on the actions of criminals, they can in the police control center is very convenient to see the criminals all the regions and lines of action to achieve the timely detection of crime dens, address security risks. GPS tracking in the car, the platform is essential, now in the country there are many such platforms, which built a variety of the latest electronic maps and satellite images GOOGLE. The label always upload GPS vehicle tracking device location information, allowing users to clear the understanding of the target location.
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GPS and National Security
In a recent international news coverage, people often find that countries are increasingly using sophisticated techniques to obtain confidential information of other countries. Asia, for example, the sky has the United States, Japan and other countries of the spy satellite, sea, many probes, the island country of hundreds of stations, there are very large radar base. In this context, China has recently found a row of illegal aliens within Chinese territory mapping. They do so for different purposes, but one thing is certain is that it jeopardized China's national security. Japan last April Comprehensive Research Institute for the Japanese secretly deployed four Ebinur northwest Xinjiang area for illegal surveying and mapping. They carry GPS (Global Positioning System), geographical data collected in the Ebinur area, the move has aroused the attention of local police. National mapping authorities in the investigation and found that they had collected 25 points in the geographic data, in violation of the Chinese territory mapping of foreigners in China's legal requirements. The four Japanese have been the deadline to leave, pay a fine. Long after the Director of the Institute dedicated to Xinjiang Tian Gaomin apology and remorse. More serious one occurred in 2006, the Japanese Land Information Technology Co., Ltd. Dalin, director of the Institute take place under the leadership of privately away from Hotan Airport less than 100 meters of a dwelling erected on the roof of a GPS positioning equipment as a fixed station, the other as a rover GPS receiver, accurate location of the region access to specific data. Many people now have an understanding of the errors that technology is so advanced, like the Google satellite maps are available free of charge high-resolution image service in the field, mountains landscape, cottage high-rise buildings, roads and railways can clearly see the satellite positioning is gradually used extensively for business services, geographic data, what the secret to speak of! ? But in fact Google provides only image map, the angle of the image is just overlooking it, the real use in military, scientific research must be on the plane coordinates, altitude and other specific data to correctly determine the objectives and position in the the military really has hit the target of practical value. China's excavator industry, installation and use of excavators dedicated GPS intelligent service system more and more enterprises, more and more common. The one hand, in order to meet the needs of financial management, on the other hand the owner for the service sector and the excavator to provide real-time remote device for more information to enable them to keep abreast of the excavator working conditions and fault conditions. However, intelligence services excavator dedicated GPS system with three-dimensional precise positioning, remote transmit data, and remote lock your car and so on. If the construction of our land excavator is being installed by a large number of foreign-controlled GPS system, intelligence services, will have significant national security risks, the excavator of the GPS installed in the intelligent service system is likely to become an important strategic leaking of information I content of the device. As intelligent service system has a GPS car remote locking feature, the controller may make a large number of projects at any time paralyzed. Taking a Japanese-funded enterprises, for example, the company's annual production and sales of excavators thousands of first million, totaling 9.6 million square kilometers distributed in China under construction on the land excavators have many tens of thousands, most of the excavators are installed on the GPS intelligent service system. With support for the system servers are located in foreign countries, all the collected data all sent to Japan, has been treated or filtered the data before returning a small part of China, this is a serious incident in violation of Chinese law, should attract attention of other companies.
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Four GPS systems worldwide
United States GPS: the 20th century by the U.S. Department of Defense since the early 70's design, development, all built in 1993. In 1994, the United States announced to the world in 10 years the right to use GPS free of charge, but the United States from foreign countries only to the low accuracy of the satellite signal. It is believed that the United States _set_ up the system "back door", in the event of war, the United States can turn off certain areas of information services. European "Galileo": In 1999, Europe propose a plan, ready to launch 30 satellites to form the "Galileo" satellite positioning system. This year the program officially started. Russian "GLONASS": not yet deployed. Began in the 70's, need to ensure at least 18 satellites covering the whole territory of Russia; such as to provide global positioning services, you need 24 satellites. China's "Compass": In 2003 the opening of Compass built and run, unlike GPS, "Compass," the command and control aircraft and terminals can be two-way communication. May 12 last year after the earthquake in Sichuan Province, Sichuan, Beijing Armed Police Command Center and the use of armed force, "Compass" had hundreds of exchanges. Compass II series of satellites into the network this year will be the peak period is expected to form in 2015 by the thirty composed of several satellites with global coverage system.
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Mechanical principle of GPS area
gps 机械领域的GPS的原理
gps 机械领域的GPS的原理
GPS is in the machinery there is another meaning: Geometrical product specifications (Geometrical Product Specifications) - referred to as GPS. There are many standards on the GPS, which GB / Z 20308-2006 "Geometrical Product Specifications (GPS) master plan" is the foundation. The principle of GPS 1, GPS system, the composition of the GPS consists of three separate parts: ● space segment: 21 operating satellites, three spare satellites. ● ground support system: a master control station, three into the station, five monitoring stations. ● part of the user equipment: receiving GPS satellites transmit signals to obtain the necessary navigation and positioning information, the data processing, the navigation and positioning work. GPS receiver hardware generally by the host, antenna and power supply. 2, GPS positioning principle The basic principle of GPS positioning is based on instantaneous position of the satellite high-speed movement known as the initial data, the use of space from the rear of the intersection of methods to determine the location of the point under test. As shown, assuming t time point tested placed on the ground GPS receivers, GPS signals reach the receiver can determine the time △ t, coupled with the receiver the received satellite ephemeris and other data to determine the following four an equation: The four equations tested point coordinates x, y, z, and Vto unknown parameters, which di = c △ ti (i = 1,2,3,4). di (i = 1,2,3,4) are the satellite 1, satellite 2 and satellite 3, the satellite 4 to the distance between the receiver. △ ti (i = 1,2,3,4) are the satellite 1, satellite 2 and satellite 3, the signal reaches the receiver 4 satellite experienced time. c for the GPS signal propagation speed (the speed of light). Significance of each parameter of four equations as follows: x, y, z coordinates for the point under test space rectangular coordinates. xi, yi, zi (i = 1,2,3,4) are the satellite 1, satellite 2 and satellite 3, the satellite 4 times the space in Cartesian coordinates t, Satellite navigation data could be obtained. Vt i (i = 1,2,3,4) are the satellite 1, satellite 2 and satellite 3, 4 satellite bell satellite clock errors, provided by the satellite ephemeris. Vto for the receiver clock error. From the above equation can be calculated by the four coordinates of the point under test x, y, z, and the receiver clock error Vto. On what basis do the GPS positioning? GPS receivers on the ground to accept at least four in the sky satellite GPS positioning signal (electromagnetic wave). Reach the GPS positioning signal receiver according to the time difference, GPS receivers can calculate their exact distance from the satellite. GPS satellite positioning and because the location is known in heaven, so the formula can be put in this position and just get the distance, converted the GPS receiver on the ground of the location (latitude and longitude, altitude, etc.). GPS car navigation systems polarized Entered a new period, the consumer demand for the product began to shift in value, of course, occupy the mainstream of consumer prices alone mode, but has gradually polarized distinction. One category is represented by OEM manufacturers such as processing the brand, still use the price advantage of a cheaper route. While the other is based on industry leading brands such as new branches and Anygo companies represented, focusing on product development and process optimization, and have become the direction of the development of new-vehicle GPS.
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GPS stands for:
GPS is in English Global Positioning System (GPS) short, while the Chinese referred to as "ball-bit system."
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Four GPS systems worldwide
United States GPS: the 20th century by the U.S. Department of Defense since the early 70's design, development, all built in 1993. In 1994, the United States announced to the world in 10 years the right to use GPS free of charge, but the United States from foreign countries only to the low accuracy of the satellite signal. It is believed that the United States _set_ up the system "back door", in the event of war, the United States can turn off certain areas of information services. European "Galileo": In 1999, Europe propose a plan, ready to launch 30 satellites to form the "Galileo" satellite positioning system. This year the program officially started. Russian "GLONASS": not yet deployed. Began in the 70's, need to ensure at least 18 satellites covering the whole territory of Russia; such as to provide global positioning services, you need 24 satellites. China's "Compass": In 2003 the opening of Compass built and run, unlike GPS, "Compass," the command and control aircraft and terminals can be two-way communication. May 12 last year after the earthquake in Sichuan Province, Sichuan, Beijing Armed Police Command Center and the use of armed force, "Compass" had hundreds of exchanges. Compass II series of satellites into the network this year will be the peak period is expected to form in 2015 by the thirty composed of several satellites with global coverage system. The principle of GPS 1, GPS system, the composition of the GPS consists of three separate parts: ● space segment: 24 operating satellites, three spare satellites. ● ground support system: a master control station, three into the station, five monitoring stations. ● part of the user equipment: receiving GPS satellites transmit signals to obtain the necessary navigation and positioning information, the data processing, the navigation and positioning work. GPS receiver hardware generally by the host, antenna and power supply. 2, GPS positioning principle The basic principle of GPS positioning is based on instantaneous position of the satellite high-speed movement known as the initial data, the use of space from the rear of the intersection of methods to determine the location of the point under test. As shown, assuming t time point tested placed on the ground GPS receivers, GPS signals reach the receiver can determine the time △ t, coupled with the receiver the received satellite ephemeris and other data to determine the following four an equation: The four equations tested point coordinates x, y, z, and Vto unknown parameters, which di = c △ ti (i = 1,2,3,4). di (i = 1,2,3,4) are the satellite 1, satellite 2 and satellite 3, the satellite 4 to the distance between the receiver. △ ti (i = 1,2,3,4) are the satellite 1, satellite 2 and satellite 3, the signal reaches the receiver 4 satellite experienced time. c for the GPS signal propagation speed (the speed of light). Significance of each parameter of four equations as follows: x, y, z coordinates for the point under test space rectangular coordinates. xi, yi, zi (i = 1,2,3,4) are the satellite 1, satellite 2 and satellite 3, the satellite 4 times the space in Cartesian coordinates t, Satellite navigation data could be obtained. Vt i (i = 1,2,3,4) are the satellite 1, satellite 2 and satellite 3, 4 satellite bell satellite clock errors, provided by the satellite ephemeris. Vto for the receiver clock error. From the above equation can be calculated by the four coordinates of the point under test x, y, z, and the receiver clock error Vto. On what basis do the GPS positioning? GPS receivers on the ground to accept at least four in the sky satellite GPS positioning signal (electromagnetic wave). Reach the GPS positioning signal receiver according to the time difference, GPS receivers can calculate their exact distance from the satellite. GPS satellite positioning and because the location is known in heaven, so the formula can be put in this position and just get the distance, converted the GPS receiver on the ground of the location (latitude and longitude, altitude, etc.). Latest trends in GPS Car navigation systems is the use of the latest trends in Bluetooth (Bluetooth) wireless technology, receive signals transmitted from GPS vehicle. This car system only needs to receive and process satellite signals, the display device is responsible for the storage and location maps overlap. So, If you already have handheld computers, only need to purchase a signal receiver and mapping software on it; Pocket PC to make the use of a machine. In fact, many phones already have GPS functionality, if the overlap with the map feature can be turned into a mobile navigation system.
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Mechanical principle of GPS area
GPS is in the machinery there is another meaning: Geometrical product specifications (Geometrical Product Specifications) - referred to as GPS. There are many standards on the GPS, which GB / Z 20308-2006 "Geometrical Product Specifications (GPS) master plan" is the foundation.
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GPS Maps
GPS map is the development of computer technology with a new generation of geographic information carrier, GPS Maps born out of the map, the map stored in digital presentation, and can only be used in the computer. GPS map with the display, transmission, and analysis capabilities, GPS maps can provide a better presentation than the traditional mapping methods, such as enlargement, reduction, roaming, searching and path planning
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Mapping Wikipedia
The Global Positioning System (Global Positioning System). Simply put, this is a worldwide 24-satellite satellite system. This system ensures that at any time, any point on Earth can be simultaneously observed four satellites, the satellite can be collected to ensure the observation points to the latitude and longitude and height to achieve the navigation, positioning, timing and other functions. This technology can be used to guide aircraft, ships, vehicles and personal, safe and accurate along the _select_ed route, arrive at the destination. Global Positioning System (GPS) is the 20th century by the U.S. armed forces 70 years the joint development of a new generation of space satellite navigation and positioning system. Its main purpose is to land, sea and air three major areas of real-time, weather and global navigation services, and for intelligence gathering, surveillance and emergency communications, and other nuclear explosion, some military purpose, the United States an important component to dominate the global strategy. After 20 years of research laboratory at a cost of $ 30,000,000,000, to March 1994, the global coverage of up to 98% of the 24 GPS satellite constellation has been laid to complete. GPS global satellite positioning system consists of three parts: the space segment --- GPS constellation; ground control segment --- ground monitoring system; user segment --- GPS signal receiver. The predecessor of GPS GPS system, the predecessor to the U.S. military developed a transit satellite positioning system (Transit), 1958 was developed, 64 was officially put into use. The system with 5-6 satellites of the satellite network to work around the Earth 13 times per day and can not be given a high degree of information, is not satisfactory in terms of positioning accuracy. However, the meridian instrument system allows R & D department of the satellite positioning achieved initial experience, and verified by the feasibility of the satellite positioning system, developed for the GPS system laid the groundwork. As shown in the GPS navigation and the great superiority of the existence of the meridian instrument systems and ship navigation on the submarine's huge flaws. U.S. armed forces and the civilian sector felt the urgent need for a new satellite navigation system. To this end, U.S. Naval Research Laboratory (NRL) proposed the use of named Tinmation 12-18 satellites global positioning height 10000km net programs, and in 67 years, 69 years and 74 years of the launch of a test satellite, In these preliminary test of the atomic clock on the satellite timing system, which is the basis of GPS precise positioning system. The Air Force has put forward 621-B of each constellation 4-5 3-4 satellites constellation program, in addition to one of these satellites orbit outside with the rest of the use of inclined orbit period of the 24h plans to pseudo-random code (PRN) of satellite-based ranging signal transmission, and its powerful features, when the signal density of less than 1% of ambient noise, also can it be detected. The successful application of pseudo-random code is a GPS system can be an important basis for success. Navy's plan is mainly used to ship with low dynamic 2-D positioning, for the Air Force's plan to provide high dynamic service, but the system is too complicated. Since both systems simultaneously will cause a huge development costs and here are two programs designed to provide global positioning, so the 1973 U.S. Department of Defense who will be 2 combined, led by the Department of Defense Joint Satellite Navigation Projects Agency (JPO) leadership, will also _set_ up offices in the Los Angeles Air Force Space Division. Many members of the agency, including the U.S. Army, Navy, Marine Corps, Ministry of Communications, Defense Mapping Agency, NATO and Australian representatives. 1. Space segment 2. Ground control segment Ground control segment consists of a master control station, five global ground control stations and three components. Stations are equipped with precision cesium clocks and continuous measurement of all visible to the satellite receiver. Stations will obtain satellite data, including the ionosphere and meteorological data, preliminary treatment, transfer to the master station. Master station tracking data collected from various monitoring stations, calculated the orbit of the satellite
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GPS (Global Positioning System) and GIS (geographic information system) one
gps GPS(全球定位系统)和GIS(地理信息系统)之一
GPS (Global Positioning System), GIS (geographic information system) to take us into a figure of the Earth, will help us better understand the planet we live on. As more and more the appearance of civilian GPS receivers, the use of GPS technology for commercial activity or outdoor adventure activities have become a trend. Whether water skiing, cycling tourism, fishing, hunting, rafting, adventure or for scientific research or data collection, GPS receivers are a special position to help you determine an excellent tool. For those who lack sense of direction, it can help you and your family away on holiday in the right way, not because lost and disappointed with the return. Global Positioning System Global Positioning System is composed of a series of satellites, which provide high-precision 24-hour worldwide positioning and navigation information. Rather, it is from 2 4 along the height of 12,000 kilometers from Earth, orbiting NAVSTAR GPS satellites, constantly sent back to the precise time and their location. GPS receivers also listen to 3 to 12 satellite signals to determine the ground or the location of objects near the ground, as well as their speed and direction. GPS receiver uses GPS satellites transmit signals to determine the location of the satellite in space and time of transmission based on radio waves to calculate the distance between them. And so calculate at least 3 to 4 after the relative position of satellites, GPS receivers can use trigonometry to calculate their position. Each GPS satellite has four high-precision atomic clock, along with a real-time updated database records the location and other satellites are now running track. When the GPS receiver determines the position of a satellite, it can download all the other satellite location information, which helps it more quickly obtain the necessary information on other satellites. Accuracy Despite high-precision atomic clocks, positioning is still lurking in the number of errors. _Select_ive Availability (SA) is the U.S. Department of Defense to provide non-military GPS users to program, for security considerations, it slightly reduced the number of positioning accuracy. When the SA work, your positioning accuracy between 50m ~ 100m. Even without the SA, some other error is to be considered. The most obvious error is due to changes in the Earth's ionosphere caused by, their speed of GPS radio waves affect. Another reason for the error is caused by water vapor in the atmosphere. However, these errors are minimal. GPS accuracy can be improved through the DGPS function, it means your receiver can receive the GPS receiver adjacent signals. Use GPS was originally for the military to provide precise positioning and established, so far it is still controlled by the U.S. military. Military GPS is mainly used to identify and track products in the field of a moving soldiers and equipment, coordinates, navigation to the sea in ships, for military aircraft provide location and navigation information. GPS is also commerce flourish, mainly used in consumer GPS mapping survey, aviation, marine navigation, vehicle tracking systems, mobile computer and cellular phone platforms and so on. Drawing from a series of survey positioning system components, typically require special GPS equipment. The application in the investigation are: the structure and engineering surveying, road surveying and geological studies. The data collected can be later estimated in real time can also be used in the field. Mapping process using a large number of GIS data in the database, as well as paper maps of the data. Many businesses and government agencies use GPS devices to track the location of their vehicles, which generally require the help of wireless communications technology. Some GPS receivers with integrated radios, wireless phones and mobile data terminal to meet the needs of fleet management.
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GPS (Global Positioning System) and GIS (Geographic Information System) II
Civilian equipment In recent years, more and more consumers affordable GPS receivers appeared. As technology advances, more and improve the function of these devices, almost every month new features appear, but coming down in price, size is also smaller and smaller. GPS devices also couple of years ago as daunting as the work of art, and now consumers can finally have a long-standing dream of GPS receivers, and also with previously undreamed of many advanced features. Consumer GPS hand_set_ price from several hundred dollars to several thousand dollars, they basically have 12 parallel channels and data capabilities. Some even connected with the portable computer, you can upload / download GPS information, and is accurate to street level mapping software, PC's screen can track your location in real time or automatic navigation. Here are some of the most commonly used GPS receiver. 1. Car navigation systems The development of computer and communications people's lives more quickly, easily, car navigation and mobile office has swept the world, and has gradually become an indispensable part of society. In Japan, the United States and other countries, for the convenience of users, many car manufacturers when the vehicle equipped with factory navigation and mobile office equipment. In China, similar to the product development work has just begun. 2.GPS hand_set_ GPS handhelds is the use of GPS made the basic principles of design, compact size, easy to carry, an independent real-time using an all-weather navigation equipment. Good hand_set_ necessary conditions are: high sensitivity, storage capacity, the external interface to complete. GPS hand_set_-use can be divided into land use type, air-to-use, sea-to-use. Figure 2 is a land-use GPS handhelds. Generally do not have built-in land-use maps, the main point of using route recording, _select_ the waypoint can be automatically generated route. Built-in antenna makes the model compact, it is the most widely used GPS equipment; air-to-use airspace map provides global and regional maps, high sensitivity, suitable for high-speed road to locate the aircraft; sea-to-use built-in global charts , large screen, offers can be fixed to the hull of the supporting bracket and the antenna.
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GPS (Global Positioning System) and GIS (geographic information system) of the three
Most GPS receivers are easy to install and use, and user manual can help you quickly learn how to install the battery, determine the initial position, or enter a location. When you open a new site for the first GPS receiver, if you enter an estimate of the approximate location (for example, the coordinates of the neighboring cities) will help you quickly come to the satellite location device to quickly locate. If the device is a cold start, or you are not the last time you near the storage location, the general orientation may take 15 minutes; but if you give it a tip, or your position in the vicinity of a store, it normally takes 3 to Location 5 minutes. GPS receiver to the way the input data vary due to equipment, and some are combined with the menu, down arrow to _select_, and some equipment is as simple as using the telephone keypad. Common features Most GPS devices have some buttons on the panel to guide you to a different operating options. Perhaps their names are not the same, but the features are similar. They may allow you to view a navigation screen, view the available satellite signals, check the location of the directory, list, or to the _select_ed target direction. The main function is to display your position, including the current coordinates, altitude and time, if the _select_ed destination or route, it also indicates the direction to the destination. Other common features with navigation, menus, satellite status, list of street signs or waypoint / route list, _set_ options, distance, yaw, last positioning location, sunrise / sun_set_ time. Maps with maps using different coordinate systems use different, the two most commonly used U.S. Geological map is: 1. LAT / LONG vector map: longitude, latitude, minutes and seconds; 2. UTM grid map, in meters . LAT / LONG is our most familiar form, the extreme position from the equator the Earth is divided equally into 90 degrees north latitude and 0 or latitude (parallel lines on the globe), while the other from east to west into the Earth from 0 to longitude 360 degrees (the arc on the globe), the line through Greenwich, England, called the prime meridian. Coordinates calculated by this artificial distance between two points is difficult, because our survival is the ellipse of the Earth. UTM coordinates are those who need accurate information from the user's choice for the map. The choice of a radial coordinate system, indicating the east or west you how many meters it, and your south or north of the equator, the number of meters. Most GPS devices in _set_tings allows you to _select_ LAT / LONG or UTM or other coordinate system as your coordinate system, when you have the coordinates of your location, you can find on the map, in order to find your exact location address. When you find a destination on the map, you can enter the coordinates into their GPS receiver you to form a line. Clear plastic ruler can be used in the TOPO map or UTM map measurement, it is easier to estimate the coordinates of a location, a number of GPS devices have this feature: you can measure a position to map the distance from the lower right corner, then the map name and scale as The location name.
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Wikipedia Daquan
GPS-1200-Ⅲ type of high frequency vibration sieve GPS III, a 1200 high frequency vibration of a thin screen
