Model- and Programm Developments for cm-Positioning with GPS

des Instituts für Geodäsie

Heft 20-2/1985

Model- and Program Developments
for cm-Positioning with GPS

Universität Hannover


In: WELSCH, Walter M. / LAPINE, Lewis A. (Hrsg.) [1985]:
International Federation of Surveyors - FIG -
Proceedings Inertial, Doppler and GPS Measurements for National and Engineering Surveys
Joint Meeting of Study Groups 5B and 5C, July 1-3, 1985

Schriftenreihe Universitärer Studiengang Vermessungswesen, Universität der Bundeswehr München, Heft 20-2, Neubiberg, S. 553-565.


With phase measurements on the carrier signals of GPS satellites a highly accurate relative geodetic positioning is possible. A main problem concerns the determination of the phase ambiguities. A method which helps to solve this problem using simultaneous P-code and carrier measurements is presented. The carrier and code measurements on GPS satellite signals are measurements of the signal transmission times. The carrier phases are obtained with a very high resolution but they are ambiguous. Accumulated code phases are used to determine the carrier phase ambiguities. Pseudoranges with a noise level of a few millimeters are obtained after a sufficient long time of observation. This algorithm is independent on the receiver location and dynamics. Thus, the resulting pseudoranges can be used for static as well as dynamic positioning. The basic model and software developments at the University of Hannover for the simultaneous determination of absolute and relative geodetic positions by use of ranges are described.

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