Laser altimetry data processing and combined surveying application of ZY3-03 satellite

ZY3-03 is a land remote sensing satellite for 1: 50 000 stereo mapping built by the Ministry of Natural Resources. It is equipped with operational laser altimeter, which is mainly used to obtain high-precision elevation control points. In this paper, aiming at the laser altimetry data of ZY3-03 satellite, the standardized surveying processing flow and the method of extracting elevation control points is studied. Moreover, the accuracy verification in Sunid Right Banner of Inner Mongolia and Suzhou of Jiangsu Province is implemented, and the combined surveying and mapping application in Heilongjiang and Hebei areas is experimented and validated. The accuracy verification results show that the elevation accuracy of ZY3-03 laser points in the flat area of Sunid Right Banner in Inner Mongolia is (0.051±0.232) m, and the overall accuracy of the laser points in the urban area of Suzhou, Jiangsu is (0.414±6.213) m, and the elevation accuracy after elevation control points extraction is (−0.526±0.624) m, which can meet the elevation control requirement of 1:50 000 mapping; The application of combined surveying and mapping shows that the elevation accuracy of stereo images can be improved from 5.27 m to 2.58 m in flat area of Heilongjiang and from 11.25 m to 4.45 m in Taihang mountain area of Hebei by using laser elevation control points derived from the ZY3-03 satellite. It is concluded that the elevation accuracy of stereo images can be effectively improved by using laser elevation control points of ZY3-03 satellite in both flat and mountainous areas, and the requirement of 1:50 000 mapping can be met.