Subject: [SLR-Mail] No. 163: From: Frank G. Lemoine, NASA GSFC <[Mailed Frank Lemoine ]> ******************************************************************************** SLR Electronic Mail 1998-10-08 21:00:00 UTC Message No. 163 ******************************************************************************** Author: Frank G. Lemoine, NASA GSFC Subject: Subject: GFO-1 Update and SLR Tracking Dear Colleagues, We have just been informed by Ball Aerospace (Boulder, Colorado) that the radar altimeter on GEOSAT Follow-On (GFO) will be turned on again for a period of at least three weeks beginning this weekend, October 11, 1998. The spacecraft has been experiencing CPU resets, but changes should now alleviate this problem. As you are all aware, the GPS payload still does not provide useful data and aside from some Doppler/TRANET-type tracking, Satellite laser ranging (SLR) provides the only hope for determining precise orbits for this satellite. We hope all stations (US and international) will track GFO when possible, in accordance with ILRS guidelines, although we understand that a number of campaigns are now underway (GEOS-3, GLONASS, etc.) that are also making demands on station time. The issue of SLR tracking for GFO has been fully discussed with the NASA SLR program and the ILRS central bureau. The National Oceanic and Atmospheric Administration (NOAA) will release Geophysical Data Records (GDR´s) for GFO altimeter data, once the Calibration/Validation phase of the mission is complete. However, Cal/Val needs at least several months of altimeter data, together with precise orbits, -so the participation of the world SLR stations is important. Interested parties may check on GFO mission status by viewing the URL http://gfo.bmpcoe.org/Gfo/Exec_col/exec_col.htm Thank you for your interest and support of this mission. Sincerely, Frank G. Lemoine GFO-1 NASA/ Gravity Field & Precise Orbit Determination Investigator Space Geodesy Branch, Code 926 Laboratory for Terrestrial Physics NASA Goddard Space Flight Center Greenbelt, Maryland 20771 USA email: flemoine@olympus.gsfc.nasa.gov -- [Mailed From: Frank Lemoine ] ********************************************************************************