The objective of this study was to determine the feasibility of using PSPP coordinates to accurately rectify SPOT 2 Panchromatic imagery by first, second and third order polynomial transformations. The study presented the rectifying results of the attainable accuracy of ground points versus number and distribution of ground control points (GCPs), versus the image measurement errors of GCPs and checkpoints and versus the order of the polynomial transformation. Various experimental schemes involving geometric strength with various configurations of polynomial transformation, the influence of the number and distribution of GCPs, and the influence of the image measurement errors of GCPs and checkpoints and the influence of GCPs to and inaccessible region were performed. Some recommendation for potential of SPOT Panchromatic imagery in mapping was finally drawn up from this research. Two SPOT Panchromatic images covering Chantaburi province were used in this study as the two images had different topographic characteristics where one was a flat terrain adjacent to the sea and the other was flat and hilly. The results of polynomial transformation using coordinates derived from PSPP yielded 0.5-0.7 pixel size accuracy. The optimum number of GCPs was 15 and 21 points when using second and third order polynomial transformation. The study revealed that first order polynomial transformation was not suitable to rectify SPOT Panchromatic. A well spread distribution of GCPs was highly recommended. The study of planimetric error without GCPs in the inaccessible region was analysed using 2 patterns of GCPs distribution namely a curvilinear and polygon. The results revealed that 25 m planimetric accuracy can be obtained at 20 km from the curvilinear and 25 km from the polygon’s centroid, respectively.
