Acta Geodaetica et Cartographica Sinica ›› 2020, Vol. 49 ›› Issue (1): 79-91.doi: 10.11947/j.AGCS.2020.20190226

• Photogrammetry and Remote Sensing • Previous Articles     Next Articles

Using DEM as full controls in block adjustment of satellite imagery

CAO Hui1, TAO Pengjie1, LI Haihong2, ZHANG Zuxun1   

  1. 1. School of Remote Sensing and Information Engineering, Wuhan University, Wuhan 430079, China;
    2. Hubei Geomatics Technology Group Inc., Wuhan 430074, China
  • Received:2019-06-05 Revised:2019-08-08 Published:2020-01-16
  • Supported by:
    The National Key Research and Development Program of China (No. 2018YFD1100405);The National Natural Science Foundation of China (No. 41971420)

Abstract: An algorithm is proposed in this study which directly uses digital elevation model (DEM) as full controls in block adjustment of satellite images, it is an application and extension of "cloud control" in photogrammetry. Different from the indirect geo-referencing method based on the registration of image-derived DSM or DEM with reference DEM, a DEM is considered as full geometric constraints and directly introduced into the block adjustment of satellite images based on the RFM model, by minimizing the squared sum of distances from tie points to the terrain surface described by DEM. By using DEM as exclusive control, the horizontal and vertical positioning accuracies of stereo satellite images can be upgraded without any ground control points (GCPs). A total of 330 stereo scenes of Chinese Mapping Satellite-1 images covering the whole area of Shandong Province are used for experimental tests, and three different open source DEM data of 1″ grid AW3D30, ASTER GDEM and 3″ grid SRTM GL3 are used as control data, respectively. The adjustment results are validated by using 100 well-distributed ground check points. Experiments show that the positioning accuracy is depended on the accuracy of DEM itself. While using AW3D30 as full controls, which is the most accurate one among the three global DEMs in experiments, the block adjustment accuracy of 4.9 m (about 1 pixel) in horizontal direction and 2.8 m in vertical direction can be achieved, respectively. Which is similar with the results of using 100 GCPs. It is proved that the effectiveness and feasibility of using DEM instead of ground control points as controls for block adjustment.

Key words: DEM, block adjustment, RFM sensor modelling, satellite imagery orientation without GCPs

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