Analysis and outlook of the operational topographic surveying and mapping capability of the SAR satellites

In this paper, we reviewed the operational topographic surveying and mapping capability, i. e., plane and height accuracy, that synthetic aperture radar (SAR) satellites achieve. The plane accuracy of TerraSAR-X, COSMO-SkyMed and Tianhui-2 meets the need of 1:50 000 digital orthophoto map standard. The state-of-the-art plane accuracy is 2 m which is achieved by TerraSAR-X. Meanwhile, the accuracy of operational ground control point production provided by TerraSAR-X is 3 cm. We reviewed the error sources and the calibration methods for centimetric SAR image location. The height accuracy of TanDEM-X and Tianhui-2 meets the needs of 1:50 000 digital elevation model standard. The state-of-the-art height accuracy is 0.88 m which is achieved by TanDEM-X if the dense vegetation areas and the snow-and-ice covered areas are exclusively included in the statistical results. We reviewed the error sources and the calibration methods for height measurement without ground control information. The paper is expected to provide references for the geolocation and height measurement of the domestic SAR satellites.