{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T02:09:23Z","timestamp":1760148563793,"version":"build-2065373602"},"reference-count":27,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2023,5,10]],"date-time":"2023-05-10T00:00:00Z","timestamp":1683676800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Key Research and Development Program of the National","award":["2020YFA0713503","22B0168"],"award-info":[{"award-number":["2020YFA0713503","22B0168"]}]},{"name":"Excellent Youth Project of the Hunan Provincial Education Department","award":["2020YFA0713503","22B0168"],"award-info":[{"award-number":["2020YFA0713503","22B0168"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>The spotlight image acquired by the Gaofen-3 satellite has a resolution of 1 m, which has great potential for 3-D localization. However, there have been no public reports on the 3-D localization accuracy evaluation of Gaofen-3 spotlight synthetic aperture radar (SAR) images. Here, three study areas were selected from this perspective, and the SAR spotlight stereo images of the study area were acquired using Gaofen-3. In the case of no ground control points (GCPs), based on the Rational Polynomial Coefficient (RPC) model, these images were used for initial 3-D localization; the plane accuracy was better than 10 m in general, and the elevation accuracy was worse than 37 m in general. Subsequently, the RPC model was optimized using geometric calibration technology, and the 3-D localization accuracy was assessed again. The elevation accuracy was significantly improved, which was generally better than 5 m. The plan accuracy was also improved, and it was generally better than 6 m. It can be seen that Gaofen-3 spotlight stereo images are of good quality, and high plane accuracy can be obtained even without GCPs. Geometric calibration technology improves the 3-D localization accuracy, and the elevation accuracy optimization effect is remarkable. Moreover, the optimization effect of plane accuracy is affected by the properties of stereo-image pairs. The optimization effect of plane accuracy is obvious for asymmetric stereo-image pairs, and the optimization effect of plane accuracy is general for symmetric stereo-image pairs.<\/jats:p>","DOI":"10.3390\/rs15102512","type":"journal-article","created":{"date-parts":[[2023,5,11]],"date-time":"2023-05-11T01:37:24Z","timestamp":1683769044000},"page":"2512","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Improvement and Assessment of Gaofen-3 Spotlight Mode 3-D Localization Accuracy"],"prefix":"10.3390","volume":"15","author":[{"given":"Nuo","family":"Chen","sequence":"first","affiliation":[{"name":"School of Automation and Electronic Information, Xiangtan University, Xiangtan 411105, China"}]},{"given":"Mingjun","family":"Deng","sequence":"additional","affiliation":[{"name":"School of Automation and Electronic Information, Xiangtan University, Xiangtan 411105, China"},{"name":"National Centre for Applied Mathematics in Hunan, Xiangtan 411105, China"}]},{"given":"Di","family":"Wang","sequence":"additional","affiliation":[{"name":"School of Automation and Electronic Information, Xiangtan University, Xiangtan 411105, China"}]},{"given":"Zhengpeng","family":"Zhang","sequence":"additional","affiliation":[{"name":"School of Automation and Electronic Information, Xiangtan University, Xiangtan 411105, China"}]},{"given":"Yin","family":"Yang","sequence":"additional","affiliation":[{"name":"National Centre for Applied Mathematics in Hunan, Xiangtan 411105, China"},{"name":"School of Mathematics and Computational Science, Xiangtan University, Xiangtan 411105, China"}]}],"member":"1968","published-online":{"date-parts":[[2023,5,10]]},"reference":[{"key":"ref_1","first-page":"1594","article-title":"Accurate extraction and analysis of mountain glacier surface motion with GF-3 imagery","volume":"43","author":"Zhang","year":"2021","journal-title":"J. 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