Subject: [IGSMAIL-4228]: To: igsmail@igscb.jpl.nasa.gov, igsleo@igscb.jpl.nasa.gov Date: Thu, 9 Jan 2003 17:46:17 +0000 (GMT) Message-Id: <20030109174618.0A91E11B20@ishtar.gsfc.nasa.gov> From: flemoine@ishtar.gsfc.nasa.gov Sender: owner-igsmail Precedence: bulk ****************************************************************************** IGS Electronic Mail 09 Jan 11:47:06 PST 2003 Message Number 4228 ****************************************************************************** Author: Remko Scharroo, Frank Lemoine, Doug Currie. Subject: Session G16, Satellite Surface Forces and Satellite Rotational Dynamics at EGS-EUG-AGU Assembly. Dear Colleagues, We draw your attention to the following special session at the EGS-EUG-AGU Joint Assembly. April 6-11, 2003, in Nice, France. We especially encourage submittals that will discuss non-conservative force modelling, and the potential improvements that might be realized from the application of acclerometer data from current and future gravity missions, as well as papers that discuss aspects of surface modelling for geodetic satellites. Please note the abstract deadling of Wednesday, January 15, 2003 at 24:00 GMT. Further information may obtained at the EGS website: http://www.copernicus.org/egsagueug/index.html We look forward to seeing you in Nice. Regards, Convenor: Remko Scharroo (remko.scharroo@noaa.gov) Co-Convenors: Doug Currie (currie@physics.umd.edu) Frank Lemoine (flemoine@geodesy2.gsfc.nasa.gov) G16 Satellite Surface Forces and Satellite Rotational Dynamics (co-sponsored by GI) ------------------------------------------------------------------------------- While gravity models are rapidly improving, surface forces are becoming the largest source of satellite orbit errors for a large range of orbital altitudes. For low-flying satellites atmospheric drag is not only a significant force, it is also difficult to model. Deficiencies in drag modelling are the result of uncertainties in the density and composition of the atmosphere, the interaction between the atmospheric particles and the satellite surface, and motion of the atmosphere. Particularly during periods of high solar activity, the density and composition of the atmosphere at the satellite altitude can vary rapidly, to as much as an order of magnitude within a few hours. For satellites in higher orbits, drag becomes less important, while solar radiation pressure becomes increasingly important compared to gravity. The major source of uncertainty in radiation pressure modelling are the reflective properties of the satellite surface, and, for satellites without attitude control and monitoring, the attitude. In the case of LAGEOS I and II, significant advances have been made recently to model the attitude, with important implications for the surface force modelling. Because of their close interaction, both satellite surface forces and rotational dynamics are the topic of this session. We particularly welcome papers dealing jointly with both subjects. Encouraged are also submissions dealing with new methods for modelling of atmospheric drag, the interaction between particles or photons and the satellite surface, the dependence on solar activity, modelling of Earth albedo, and despin and spin axis orientation of geodetic satellites.