2023年3月30日，由国内商业航天企业航天宏图信息技术股份有限公司（以下简称航天宏图）运营的航天宏图一号卫星（PIESAT-1）成功发射，为国产SAR卫星的发展注入了新的动力，作为“女娲星座”首发星，其具备高精度地形测绘、高分宽幅成像、高精度形变监测等能力。但目前关于该卫星的相关研究较少，亟须探索其真实的测图能力。本文利用星载合成孔径雷达干涉测量（InSAR）生产数字高程模型（Digital Elevation Model，DEM）技术流程，针对PIESAT-1独特的“1主+3辅”车轮编队构型进行相应技术调整。首先，选取了山地、丘陵、平原三种特殊的地形为研究对象，结合PIESAT-1卫星在轨测试期间获取的单视斜距复影像干涉对（L1B）数据，利用InSAR技术提取DEM， 并以ICESat-2控制点和Copernicus DEM作为参考，验证PIESAT-1的地形测绘精度。结果表明，在山地、丘陵和平原三种地形条件下，PIESAT-1 DEM产品的垂直精度均高于Copernicus DEM，RMSE值分别为4.8727m、7.8329m、0.9857m；同时，PIESAT-1 DEM产品在空间分辨率上优于Copernicus DEM产品，能够更清晰地描绘地形的细节特征；本文还考虑了植被对DEM产品精度的影响，在高植被区域，植被所产生的误差不可无视。通过本文实验表明PIESAT-1用于全球地形测绘任务时，独特的编队方式使其在空间分辨率、测绘效率、测量精度上均占据巨大优势，这为“女娲星座”的业务化应用提供了重要参考。

On March 30, 2023, the PIESAT-1 satellite, operated by the domestic commercial space enterprise Piesat Information Technology Co., Ltd. (hereinafter referred to as Piesat), was successfully launched, injecting new impetus into the development of domestic SAR satellites. As the first star of “Nüwa Constellation”, it has the ability of high-precision topographic mapping, high-resolution wide-range imaging and high-precision deformation monitoring. However, there are fewer studies on this satellite, and it is urgent to explore its real mapping capability. In this paper, we utilize the on-board InSAR to produce DEMs technology process, and make corresponding technical adjustments for the unique “1 main + 3 auxiliary” wheel formation configuration of PIESAT-1. Firstly, three special terrains, namely, mountain, hill and plain, are selected as the research objects, combined with the L1B data acquired during the in-orbit test of PIESAT-1 satellite; Then the DEM is extracted using InSAR technology. In the extraction step, the multi-baseline phase unwrapping brought by the four-star constellation of PIESAT-1 is fully utilized, and the high-precision DEM is extracted by combining with the TSPA multi-baseline phase unwrapping method; Finally, the ICESat-2 control points and the Copernicus DEM are used as the references to validate the accuracy of the terrain mapping of PIESAT-1. Results: (1) The vertical accuracy of PIESAT-1 DEM product is higher than that of Copernicus DEM under the three terrain conditions of mountains, hills and plains, with the RMSE values of 4.8727m, 7.8329m and 0.9857m, respectively.(2) The unique formation configuration of PIESAT-1 can effectively reduce the elevation error caused by vegetation, which also makes the spatial resolution of PIESAT-1 DEM products better than that of Copernicus DEM products, and is able to depict the detailed features of the terrain more clearly. The experiments in this paper show that when PIESAT-1 is used in the global topographic mapping mission, the unique formation method gives it a great advantage in spatial resolution, mapping efficiency, and measurement accuracy, which provides an important reference for the operational application of “Nuwa Constellation”.