Macrometer Satellite Surveying

Abstract

The Global Positioning System provides relative positions to 1–2 ppm with anrobservation time of 2–3 hr. The quality does not depend on weather; there is no intervisibility between stations required. The inner and minimal constraint solutions are introduced for the quality control of GPS vector observation. The problems of network maintenance assume new significance in view of the high quality of GPS observations. The 3‐ and 2‐dimensional transformations are introduced for implementing GPS vector observations into existing networks. The 3‐dimensional transformation is parameterized by scale, 3 translations, and 3 rotations. This transformation is unique, i.e., the same a posteriori variance of unit weight and residuals are obtained, even though there are different choices for the rotations. The 2‐dimensional transformation is carried out on the ellipsoid. A combined adjustment of all terrestrial and GPS observations of a local area avoids dealing with network distortions. The primary quantities are the observations and not the coordinates.