block　ortho－rectification 　for 　satellite 　images

this　paper 　proposes 　a　strate gy　that 　uses 　a　planar 　block 　ad justment　method　to 　solve 　theproblem　of 　ortho－rectification 　for 　the　orientation　parameters 　of 　all 　satellite 　images 　and　block　ortho－rectification 　for 　each　satellite 　image．this　strate gy　can　ensure 　the　uniformity　of 　absolute　positioning　accurac y　and　relative 　position　of 　satellite 　images　which　are 　ortho－rectified．using　tests 　of 　panchromatic　nadir 　13９images 　from　zy－3surveying　satellitesshow　that 　by　using　onl y　a　small　number　of 　ground 　control 　points gcps whose　planar 　accurac y　is 　5mthe　planar 　accurac y　of 　inde pendent 　check　pointsicpswas　better 　than　7 mafter　planar 　block 　ad justment．this 　accurac y　meets　chinese　1∶50　000topogra phic　map　accurac y　re quirements．in 　additionthe 　accurac y　of 　the 　tie 　points tpsin 　ad jacentimages　was　better 　than　0．5pixelsachieving　a　seamless　mosaic　level 　in　geometr y．