STEREOSCOPIC ACCURACY OF SPOT IMAGERIES 
By 
Dr. Maarouf À. M. Diefallah, 
Department of Civil Engineering, 
Qatar University 
ABSTRACT 
The SPOT system is the first space orbiting satellite with 
stereoscopic capability. Stereoscopic pairs with variable 
incidence angles and base to height ratios can be obtained. The 
availability of stereoscopic data from space will enhance the 
process of topographic mapping and maps revision for unmapped or 
poorly mapped areas around the world. 
In this investigation accuracy of stereoscopic information 
extracted from a SPOT stereo pair are tested using two 
photogrammetric methods. In the first method, a stereoscopic 
model is formed ,analytically, by the conventional procedure of 
relative orientation. Model coordinates are fitted into ground 
coordinates using three dimensional affine and polynomials 
transformations. In the second testing method, ground 
coordinates of check points are computed by intersection of 
oriented rays. This followed the determination of the exterior 
orientation elements of each individual imagery using the space 
resection equations. Residuals , in check points, and their root 
mean square values are computed in each case. 
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