Photographic and photoelectric sensors to achieve satellite surveillance of ground targets. Satellite selection of 150 ~ 280 km of near-earth orbit, to obtain a clear image. According to information sent back to the ground and divided into two categories: (1) return type. Photographic film after the ground will be stored in the satellite recycling containers, recycling containers returned to Earth from orbit; (2) the transmission type. Detection using optical imaging principle photography, then the image information recorded on tape, fly to the ground station in the controlled area, then the image information to send the ground.