一、空间信息源及其应用 1990年以来,中国的地表观测卫星信息源已非常丰富。应用这些信息的卫星地面接收站、图像处理和自动制图系统也越来越完善。80年代,三颗用于国土调查的返回式科学实验卫星相继发射,并得到了高分辨力全景假彩色图像。图像纠正和应用估价业已完成。1989—1990年,两颗极轨气象卫星相继发射,这些卫星的地面接收站网已经建成,并且已经获得覆盖全 I. Spatial Information Sources and Their Applications Since 1990, China has a very rich source of information on surface observation satellites. Satellite receiving stations using this information, image processing and automatic mapping systems are also becoming more sophisticated. In the 1980s, three returning scientific experimental satellites for homeland surveys were launched one after another, and high-resolution panoramic false color images were obtained. Image correction and appraisal have been completed. Two polar orbiting meteorological satellites were launched in 1989-1990, and the ground receiving stations of these satellites were completed and have been covered