Dear colleagues,<= /span>

we would like to draw your a= ttention to the session “G2.1 Precise Orbit Determination for Geodesy= and Earth Science” organized at the upcoming General Assembly of the= European Geosciences Union, taking place from April 23-28, 2023. The EGU23 aims to bring together geoscientists from all over = the world to one meeting covering all disciplines of the Earth, planetary, = and space sciences.

G2.1 session description:

Precise orbit determination = is of central importance for many applications of geodesy and earth science= . The challenge is to determine satellite orbits in an absolute sense at th= e centimeter or even sub-centimeter level, and at the millimeter or even sub-millimeter level in a relative se= nse. Four constellations of GNSS satellites are available and numerous posi= tion-critical missions (e.g. altimetry, gravity, SAR and SLR missions) are = currently in orbit. Altogether, outstanding data are available offering new opportunities to push orbit de= termination to the limit and to explore new applications.=

This session aims to make ac= cessible the technical challenges of orbit determination and modelling to t= he wider community and to quantify the nature of the impact of dynamics err= ors on the various applications.

Contributions are solicited = from, but not limited to, the following

areas: (1) precise orbit det= ermination and validation; (2) satellite surface force modelling; (3) advan= ces in modelling atmospheric density and in atmospheric gravity; (4) advanc= es in modelling earth radiation fluxes and their interaction with space vehicles; (5) analysis of changes in geod= etic parameters/earth models resulting from improved force modelling/orbit = determination methods; (6) improvements in observable modelling for all tra= cking systems, e.g. SLR, DORIS, GNSS and their impact on orbit determination; (7) advances in combining th= e different tracking systems for orbit determination; (8) the impact of imp= roved clock modelling methods/space clocks on precise orbit determination; = (9) advances in modelling satellite attitude.

Please consider submitting a= n abstract to this dedicated orbit session.

The deadline for abstract su= bmission is January 10, 2023 at 13:00 CET.

We are looking forward to yo= ur contribution.

On behalf of the convenors o= f session G2.1, Adrian J=E4ggi

Co-conveners: Alexandre Couh= ert, Heike Peter, Oliver Montenbruck, Jose van den IJssel=