Heights in the Bavarian Alps: mutual validation of GPS, levelling, gravimetric and astrogeodetic quasigeoids

Abstract

For many modern regional geoid and quasigeoid models accuracies of one or a few centimeters are given. Validation of these models, however, is often difficult due to the lack of independent data. In a test area of the Bavarian Alps, Germany, with dense data coverage, we carry out validation experiments using GPS, levelling and astrogeodetic observations as well as state-of-the-art regional quasigeoid models. The data cover very rough terrain and mountain peaks. We find a good mutual agreement with a typical scatter of height residuals of 1 ? 2 cm. In some areas, however, systematic residual mean values of several centimeters are obtained which are possibly due to residual quasigeoid errors or due to a weak tie to the GPS reference frame.