N. Alrousan et al., AUTOMATED DEM EXTRACTION AND ORTHOIMAGE GENERATION FROM SPOT LEVEL 1BIMAGERY, Photogrammetric engineering and remote sensing, 63(8), 1997, pp. 965-974
This paper describes the testing and validation of the photogrammetric
modules of the PCI EASI/PACE system using SPOT stereo-pairs over a hi
gh accuracy test field established in a desert area in Jordan. The mat
hematical modeling and analytical photogrammetric solution used by the
system are first described. This is followed by a description of the
algorithm employed in the automatic image matching procedure used to e
xtract a dense DEM from the SPOT digital image data. The results of ex
tensive tests of the geometric accuracy of the exterior orientation an
d analytical rectification carried out with the SPOT images using EASI
/PACE are given. The DEMs generated from five SPOT Level 1B stereo-pai
rs have been merged and validated through a comparison of the resultin
g contours with the corresponding contours generated by aerial photogr
ammetric methods, the two plots showing an excellent agreement. The fi
nal ortho-images are of a high quality in radiometric terms, while a c
heck of their geometric accuracy reveals sub-pixel accuracy. The resul
ts of this highly automated all-digital photogrammetric procedure are
of considerable relevance to those concerned with the topographic mapp
ing of extensive areas of arid and semi-arid terrain.