Gravimetric Solution Research Articles

Global satellite triangulation and trilateration results

The paper summarizes the results of the Ohio State University geometric adjustment for the coordinates at 158 satellite tracking stations. In the solution the origin of the coordinate system is defined through the ‘inner’ adjustment procedure, whereas the orientation is through the Conventional International Origin and the Greenwich Mean Astronomical Meridian, both as defined by the Bureau International de l'Heure. The scale is implemented through Secor observations and weighted height constraints. Chord distances derived from C band radar observations and from electronic distance measurements are also included, but they seem to have very little effect. The scale selected corresponds to a best fitting ellipsoid of a = 6,378,142 m and 1/ƒ = 298.25. The average standard deviation of a single coordinate is 3.9 m. Comparisons with external standards generally show good agreements: scale agreement with dynamic satellite solutions is 1:1,600,000 and with terrestrial surveys is 1:575,000; the root mean square residual of comparisons with geoid undulations from satellite surface gravimetric solutions is 6.1 m, with an average discrepancy of only −0.3 m. The paper also presents satisfactory transformation parameters for the NAD 1927, the Australian and the South American 1969 geodetic datums.