Abstract:

In response to the problem that block adjustment for satellite images cannot be solved with weak convergence geometric conditions, this paper proposed a plane block adjustment method that utilizing DEM as height constraint plane block adjustment method to improve the targeting precision of imagery. First, rational function model (RFM) with affine transformation is selected as the mathematical model of the satellite image plane block adjustment. Second, to update the ground coordinates of Tie Points (TPs), the plane coordinates of TPs were only solved in the adjustment process. Elevation values obtained using DEM interpolation. Finally, the plane coordinates of all TPs and orientation parameters of all satellite images were solved through plane block adjustment with a few Ground Control Points (GCPs). ZY-3 nadir images of two regions were tested for plane block adjustment and ZY-3 forward-nadir-back images of the same two regions were tested for stereo block adjustment. Comparison indicates that almost the same accuracy can be obtained by plane block adjustment support with 1:50000 DEM and stereo block adjustment for ZY-3 images. For ZY-3 nadir images, when global DEM with 1km grid and SRTM with 90m grid replaced 1:50000 DEM as elevation control, accuracy of plane block adjustment almost no loss. Ultimately, the test results proved the effectiveness and feasibility of the plane block adjustment method.

Key words: ZY-3 satellite imagery, stereo block adjustment, plane block adjustment, accuracy