Terrestrial—Doppler adjustment and analysis of the primary triangulation of Great Britain: preliminary report

Abstract
The 1977 readjustment of the primary triangulation of Great Britain resulted in an internally consistent geodetic framework. The remaining suspected sources of systematic error could only be detected through comparisons with satellite Doppler derived observations carried out at selected stations of the network. These comparisons are followed by a simultaneous adjustment and strength analysis involving both terrestrial observations and Doppler positional data. The results of this combined adjustment are compared with the 1977 coordinates to assess the contribution of the satellite Doppler-derived data. Details are given of the choice of the reference system, the treatment of the Doppler data and the assignment of a priori standard errors of the various types of observations. The variance-covariance analysis is carried out with real data as well as with simulated observations in order to quantify the contribution of additional satellite Doppler observations to the geometrical strength of the combined network.