HR: 0800h
AN: G51B-0080    [Abstracts]
TI: SLR Observations of ICESat
AU: * Shelus, P J
EM: pjs@astro.as.utexas.edu
AF: Center for Space Research, University of Texas at Austin 3925 W. Braker Lane, Suite 200, Austin, TX 78759
AU: Schutz, B E
EM: schutz@csr.utexas.edu
AF: Center for Space Research, University of Texas at Austin 3925 W. Braker Lane, Suite 200, Austin, TX 78759
AU: Webb, C E
EM: webb@csr.utexas.edu
AF: Center for Space Research, University of Texas at Austin 3925 W. Braker Lane, Suite 200, Austin, TX 78759
AU: Rim, H
EM: rim@csr.utexas.edu
AF: Center for Space Research, University of Texas at Austin 3925 W. Braker Lane, Suite 200, Austin, TX 78759
AU: Ricklefs, R L
EM: rlr@astro.as.utexas.edu
AF: Center for Space Research, University of Texas at Austin 3925 W. Braker Lane, Suite 200, Austin, TX 78759
AU: Yoon, S
EM: yoonseo@csr.utexas.edu
AF: Center for Space Research, University of Texas at Austin 3925 W. Braker Lane, Suite 200, Austin, TX 78759
AU: Ries, J G
EM: moon@astro.as.utexas.edu
AF: Center for Space Research, University of Texas at Austin 3925 W. Braker Lane, Suite 200, Austin, TX 78759
AB: Precision orbit determination (POD) for ICESat is performed primarily using GPS data from on-board instrumentation. However, SLR observations provide important verification of GPS-based results. Additionally, SLR operations allow the testing of the logistics of target-specific observing restrictions, in cooperation with the International Laser Ranging Service (ILRS). With some missions, target specific restrictions on SLR observations become an important issue for routine laser ranging operations. For SLR observations of ICESat, SLR stations must not shoot "up the barrel", with the possibility of harming on-board instrumentation. Several ILRS stations, notably MLRS, Zimmerwald and the MOBLAS stations, have automatic elevation-initiated laser cut-off software. They have been invited to range to ICESat under the restriction that ranging not be performed when ICESat has an elevation greater than 70 degrees, as seen from a station. Further, ICESat, at times, performs off-nadir pointing. Thus, even though ICESat may be at an elevation less than 70 degrees as seen from a station, it might still be possible for it to shoot "up the barrel". Communications must exist between the ICESat operations center and cooperating stations to assure that ranging is not performed when ICESat may be pointed in the direction of any particular station. Finally, because of the "spottiness" of the potential SLR data set for ICESat, based upon operational outages, and the fact that only a sub-set of the SLR network is used for ICESat ranging, predictions that are based only upon previously obtained SLR data might possibly not satisfy accuracy and precision requirements. To that end, we prepare standard SLR predicts using the data from ICESat's on-board GPS navigation files. In this poster we will expand upon all of these points, present some of the pit-falls encountered, review the SLR data obtained, and assess the successes.
DE: 1241 Satellite orbits
SC: Geodesy [G]
MN: 2004 AGU Fall Meeting