Subject: [SLR-Mail] No. 1103: 7110 MONL Monument Peak Update From: Van S. Husson, ILRS Central Bureau > ******************************************************************************** SLR Electronic Mail 2003-07-16 08:42:00 UTC Message No. 1103 ******************************************************************************** Author: Van S. Husson, ILRS Central Bureau Subject: 7110 MONL Monument Peak Update Reference: Jim Long report on ”Results of Calibration Survey at Station 7110, Monument Peak, California”, July 10, 2003 Dear Colleagues, As you may recall, Monument Peak (site 7110) went off-line on April 10 due to mount problems. On May 23, they resumed laser tracking activities. In the interim (in time sequence): 1. The eccentricities were measured, 2. the mount was removed, serviced, and put back in approximately the same location, and 3. the eccentricities were measured in its new location. ECCENTRICITIES -------------- Here are the Monument Peak eccentricities pre and post-mount replacement. Analysts please note that the post-mount replacement eccentricities is a RETRO-ACTIVE eccentricity change (i.e. dates back to May 23, 00:00 GMT). pre-mount removal post-mount replacement Oct 1999 May 12, 2003 June 13, 2003 Component Value(m) Value(m) Value(m) --------- -------- ------------ ------------- North (m) -0.0262 -0.0274 -0.0213 East (m) -0.0187 -0.0166 -0.0208 Up (m) +3.1890 +3.1880 +3.1880 The May 12 eccentricities are slightly different than the Oct 1999 eccentricities, but are within the 2 mm standard error of the survey methodology and equipment. The post mount replacement eccentricities was added to the master eccentricity files (UNE, XYZ) on the CDDIS. RANGE CORRECTION ---------------- Monument Peak (7110) normal point data between May 23, 2003 at 0:00 GMT and July 10, 2003 at 13:00 GMT contained a small range bias of -2.9 mm. (The offset between the Oct 1999 and the Jun 2003 calibration distances). The SLR data corrections file was updated to include this correction at: ftp://cddisa.gsfc.nasa.gov/pub/slr/slrql/slr_data_corrections.snx Any questions about the Monument Peak local surveys can be sent to Jim Long at jim.long@honeywell-tsi.com . From: ”Husson, Van” ********************************************************************************