On reduced dynamic orbits for altimetric satellites

Precise radial positioning as required for satellite altimetry has improved with enhancements in gravity field modelling to the extent that surface forces are now becoming the major source of error. To overcome deficiencies in the surface force models the adherence to the dynamic approach can be relaxed by estimation of a large number of empirical parameters. This so-called reduced dynamic approach is dependent on availability of either dense global tracking from systems such as DORIS or on the use of dual satellite crossovers to link the less precise altimetric mission with a more precise orbit. In this study we utilise the reduced dynamic approach introduced within the Newcastle orbital software, Faust, and compare and contrast results from the dynamic and reduced dynamic methodologies in terms of tracking residuals, overlaps and crossover residuals for ENVISAT and GFO.