Journal of Geodesy and Geoinformation Science (Dec 2018)
Comparison between Plane and Stereo Block Adjustment for ZY-3 Satellite Images
Abstract
Block adjustment for satellite images cannot be solved with weak convergence geometric conditions,therefore a plane block adjustment method to improve the targeting precision of images is proposed utilizing DEM as height constraint plane block adjustment method. First,a rational function model 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 are only solved in the adjustment process. Elevation values are obtained by using DEM interpolation. Finally,the plane coordinates of all TPs and orientation parameters of all satellite images are solved through plane block adjustment with a few ground control points ZY-3 nadir images for two regions are tested for plane block adjustment while ZY-3 forward-nadir-back images of the same two regions are tested for stereo block adjustment. A comparison indicates that almost the same accuracy can be obtained with plane block adjustment support using a 1∶50000 DEM and stereo block adjustment for ZY-3 images. For ZY-3 nadir images,almost no loss of plane block adjustment accuracy occurred when global DEM with 1km grid and SRTM with 90 m grid replaced the 1∶50000 DEM as elevation control,. Test results demonstrate the effectiveness and feasibility of the plane block adjustment method.
