Basic Products of the ZiYuan-3 Satellite and Accuracy Evaluation

The ZiYuan-3 satellite allows users to obtain triplet along-track stereo and four-band multispectral images within a single pass. Its basic sensor-corrected products are generated by reimaging with a virtual CCD array in which inner and exterior distortions are resolved and the introduced errors are negligible. In this study, three ZY-3 datasets (Dengfeng, Anping, and Taihang) were used to evaluate the accuracy of bundle adjustment using triplet stereo images. For both standard and long-strip scenes, the RMS errors of plane and elevation were 2.6 m and 1.6 m, respectively, when ground control points (GCP(s)) were deployed around the corners. The digital surface model (DSM) of the Dengfeng dataset was compared with a reference DEM (1:2000); the RMS errors produced varied with topography, with values of 3.9 m, 6.4 m, and 6.8 m for plain, hilly, and steep mountainous areas, respectively.