The accuracy of satellite precise orbit determination underpins fundamentally many applications of geodesy to earth and other planetary science. Our current principal challenge is to determine orbits at the centimetre, or even sub-centimetre, level. New constellations of GNSS are being launched offering new technical hurdles and opportunities; improved gravity field models are available through the extended analysis of GRACE data and new LEO position-critical missions (e.g. Jason-2, GOCE, CRYOSAT-2) are currently on orbit. Reprocessing campaigns and improved observable modelling offer outstanding experimental data to test approaches to orbit determination. However, time series analysis of estimated tracking station coordinates indicates significant energy in observable residuals at draconitic and beta-prime (solar) related periods. Modelling of satellite surface forces is still problematic. Many issues need to be explored by the community but at the same time we have strong indication of emerging techniques and models that stand to improve orbit determination against a range of metrics.

In particular we encourage contributions to the session that make accessible the technical challenges of orbit determination and modelling to the wider community, quantifying the nature of the impact of dynamics errors on geodetic parameters and the terrestrial reference frame.

This session solicits contributions in the following areas: (1) precise orbit determination and validation; (2) impacts of new gravity field models on orbit determination; (3) satellite surface force modelling; (4) advances in modelling atmospheric density and in atmospheric gravity; (5) advances in modelling earth radiation fluxes and their interaction with space vehicles; (6) analysis of changes in geodetic parameters/earth models resulting from improved force modelling/orbit determination methods; (7) relevant improvements in observable modelling for all tracking systems, e.g. SLR, DORIS, GNSS and their impact upon orbit determination; (8) the impact of improved clock modelling methods/space clocks on precise orbit determination; (9) advances in understanding and modelling satellite attitude behaviour; (10) orbit determination for other solar system missions; (11) insights into GPS long term orbit behaviour through the IGS re-processing campaigns; (12) insights into LEO long term orbit behaviour through the Jason/TOPEX reprocessing campaigns