SREL Reprint #2006




Relative Accuracy of Rectifications Using Coordinates Determined from Maps and the Global Positioning System

Allen E. Cook and John E. Pinder III


Global positioning systems (GPS) that use code phase receivers have the potential for providing more accurate coordinates for ground control points (GCPS) than do 7.5-minute quadrangle maps. To evaluate the effect of the greater accuracy of GPS in determining coordinates for satellite image,,, GGP coordinates were measured on maps and by Gps techniques and were then used to rectify Landsat Thematic Mapper, SPOT multispectral, and SPOT panchromatic images from the same area. There were major differences between rectifications using map and Gps coordinates. For Thematic Mapper data, 24 percent of the values assigned to pixels in the rectification performed using map coordinates differed from the values assigned to the same pixels in the rectification performed using the GPS coordinates. For SPOT multispectral and SPOT panchromatic images, the percentage of pixels with different assignments were greater than 40 percent. The improvements in accuracy when using the GPS data were substantial for even the relatively large Thematic Mapper pixels and warrant the use of GPS where position accuracy is essential.

SREL Reprint #2006

Cook, A.E. and J.E. Pinder, III. 1996. Relative accuracy of rectifications using coordinates determined from maps and the global positioning system. Photogrammetric Engineering and Remote Sensing 62:73-77.

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