Subject: [DORISMail] No 0214 :  


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DORISMail               09-Jan-2003 17:54:31                   Message No 0214
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Author: flemoine@ishtar.gsfc.nasa.gov 
Subject:   



Author: Remko Scharroo, Frank Lemoine, Doug Currie.
Subject: No 0214 : 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)
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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.


Please do not reply directly to this message, but send 
comments and suggestions to IDS.central.bureau@cls.fr