Ae. Cook et Je. Pinder, RELATIVE ACCURACY OF RECTIFICATIONS USING COORDINATES DETERMINED FROMMAPS AND THE GLOBAL POSITIONING SYSTEM, Photogrammetric engineering and remote sensing, 62(1), 1996, pp. 73-77
Global positioning systems (GPS) that use code phase receivers have th
e potential for providing more accurate coordinates for ground control
points (GCPs), than do 7.5-minute quadrangle maps. To evaluate the ef
fect of the greater accuracy of GPS in determining coordinates for sat
ellite images, GCP coordinates were measured on maps and by GPS techni
ques and were then used to rectify Landsat Thematic Mapper, SPOT multi
spectral, and SPOT panchromatic images from the same area. There were
major differences between rectifications using map and CPS coordinates
. For Thematic !Mapper data, 24 percent of the values assigned to pixe
ls 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 panchromati
c images, the percentage of pixels with different assignments were gre
ater than 40 percent. The improvements in accuracy when using the GPS
data were substantial for even the relatively large Thematic Mapper pi
xels and warrant the use of GPS where position accuracy is essential.