****************************************************************************** dorismail 15-Dec-2025 07:11:24 Message No 1458 ****************************************************************************** Author: Heike Peter Subject: EGU - Call for Abstracts for G2.5 "Precise Orbit Determination for Dear colleagues, We would like to draw your attention to session G2.5 "Precise Orbit Determination for Geodesy and Earth Science" to be held at the next EGU General Assembly in Vienna, Austria & online, 3-8 May 2026. See the session description below or at: https://www.egu26.eu/session/58100 Please consider submitting an abstract to this session, and note the abstract submission deadline: Thursday, 15 January 2026, 13:00 CET. Best regards, The convener team: Heike Peter, Daniel Arnold, Alexandre Couhert, Jose van den IJssel, Frank G. Lemoine 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 the centimeter or even sub-centimeter level, and at the millimeter or even sub-millimeter level in a relative sense. Four constellations of GNSS satellites are available and numerous position-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 determination to the limit and to explore new applications. This session aims to make accessible the technical challenges of orbit determination and modelling to the wider community and to quantify the nature of the impact of dynamics errors on the various applications. Contributions are solicited from, but not limited to, the following areas: (1) precise orbit determination and validation; (2) satellite surface force modelling; (3) advances in modelling atmospheric density and in atmospheric gravity; (4) advances in modelling earth radiation fluxes and their interaction with space vehicles; (5) analysis of changes in geodetic parameters/earth models resulting from improved force modelling/orbit determination methods; (6) improvements in observable modelling for all tracking systems, e.g. SLR, DORIS, GNSS and their impact on orbit determination; (7) advances in combining the different tracking systems for orbit determination; (8) the impact of improved clock modelling methods/space clocks on precise orbit determination; (9) advances in modelling satellite attitude; (10) simulation studies for the planned co-location of geodetic techniques in space mission GENESIS. -- ---------------------------------------------- Dr. Heike Peter Senior Consultant PosiTim UG Germany Tel.: +49 2255 9239616 Fax: +49 2255 9239615 Please do not reply directly to this message, but send comments and suggestions to IDS.central.bureau@cls.fr