| Date: | 1998-02-02 21:00:00 | |
| Sender: | Van S. Husson <[Mailed Van S. Husson <dsgvsh@slral2.atsc.allied.com>]> | |
| Subject: | [SLR-Mail] No. 100: Second Global Performance Report Card | |
| Author: | Van S. Husson | |
| Content: | ******************************************************************************** SLR Electronic Mail 1998-02-02 21:00:00 UTC Message No. 100 ******************************************************************************** Author: Van S. Husson Subject: Second Global Performance Report Card This is the second SLR global performance report card for the period (January 1, 1997 through December 31, 1997). During the November 1996 Shanghai SLR Workshop, Mike Pearlman presented some guidelines for high performance SLR systems. The intent was to establish metrics so that system performance could be measured and regularly reported. The metrics will provide the systems with a goal, however, these numbers are intended as a measure of minimum performance. These performance guidelines were divided into two categories, data quantity and data quality. The high performance guidelines are 1000 Low Earth Orbit (LEO) satellites passes per year, 400 LAGEOS passes per year, and a bias stability at the 20 millimeter level (mm). In this report, in order to give a more complete picture, we have extended these performance specifications to include high satellite tracking, measures of system precision, data delivery, status of configuration files, and version number of the CSTG normal point format. Data quality is measured in terms of data precision and data stability. Data precision is divided into 2 categories (LAGEOS single shot RMS, and LAGEOS normal point RMS). LAGEOS single shot RMS is the average LAGEOS RMS provided in the normal point data over this reporting period (i.e. bytes 48-51). This computation is not standardized because different stations may apply different editing levels(i.e. 2.5 vs. 3 sigma). The LAGEOS normal point RMS is based on The Center for Space Research (CSR) weekly LAGEOS report and is the average precision estimate of the normal point data set. Neither of these two precision statistics are influenced by system biases or errors in station position. The bias stability information is based on CSR weekly LAGEOS analysis. Bias stability is measured in both the short term (3 months) and long term (one year). The short term bias stability is the standard deviation about the station´s mean pass-by-pass range bias in the CSR weekly LAGEOS report for the past 3 months. The long term bias stability is the standard deviation about the CSR 15-day LAGEOS-1 mean bias for the past 12 months. It should be noted that stations that have very low LAGEOS data yield or poor quality LAGEOS data make it difficult to determine accurate station positions, which will further degrade bias stability determination. During the November 1996 Shanghai CSTG meeting, Andrew Sinclair and Van Husson proposed that all stations provide up-to-date station configuration information. The details of the format and management of this configuration information are provided in SLRMail message #48. This report contains the configuration file status report. In addition, modifications to the normal point format were also approved earlier this year and are contained in SLRMail message #47. Below is the matrix of performance statistics and status information. Column 1 is the station location name. Column 2 is the monument marker number. Column 3 is the LEO pass total. Column 4 is the LAGEOS pass total. Column 5 is the high satellite pass total. Column 6 is the single-shot LAGEOS RMS, in mm. Column 7 is the LAGEOS normal point RMS, in mm. Column 8 is the measure of short term bias stability, in mm. Column 9 is the measure of long term bias stability, in mm. Column 10 is the average data delivery time, in days, to the data centers. Column 11 is the CSTG normal point format revision number. Column 12 is a yes/no answer to the question of whether or not configuration files have been provided to the data centers. The first entry in the table is for the performance baseline/goal. Blanks in the columns mean either that there was no data or that there was insufficient data. A blank in the last column means that the system has been deactivated with no plans for operations in the foreseeable future. Stations with no reported data within the last year will be deleted from the table. Global Performance Report Card (January 1, 1997 through December 31, 1997) Columns 1 2 3 4 5 6 7 8 9 10 11 12 SS NP shor long form LEO LAG High RMS RMS stab stab del rev conf Station Name Pad# Tot Tot Tot (mm) (mm) (mm) (mm) days # files? ------------ ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ------ Baseline 1000 400 100 20 20 2 1 yes Maidanak 2 1864 238 206 233 150 26 31 47 2 0 no Komsomolsk 1868 244 73 91 150 28 2 0 no Mendeleevo 1870 212 3 0 no Simeiz 1873 154 25 61 25 1 0 no Riga 1884 673 141 46 39 10 37 44 1 1 no Katsively 1893 64 17 31 62 8 4 1 no Cuba 1953 123 2 1 no McDonald 7080 1498 403 315 16 3 10 8 1 1 yes Yarragadee 7090 2140 755 649 9 2 10 6 1 0 yes Greenbelt (M7) 7105 3581 878 457 9 2 13 8 1 0 yes Quincy 7109 187 57 12 11 2 1 0 yes Monument Peak 7110 5551 1410 1222 11 2 12 5 1 0 yes Tahiti 7124 37 4 4 8 0 yes Haleakala 7210 1852 561 580 13 2 14 9 1 0 yes Wuhan 7236 165 43 13 42 18 2 0 no Changchun 7237 2025 353 202 17 7 28 20 2 1 yes Beijing 7249 1245 154 28 48 21 101 32 2 0 no Tokyo 7308 275 76 46 30 11 56 1 1 yes Arequipa 7403 1754 357 8 3 14 6 1 0 yes Cagliari 7548 195 54 52 22 1 0 no Metsahovi 7805 719 1 1 1 no Metsahovi2 7806 11 4 1 no Zimmerwald 7810 327 70 17 49 11 20 30 1 1 yes Borowiec 7811 616 115 7 42 10 20 14 1 1 yes San Fernando 7824 1159 122 100 19 45 1 0 yes Helwan 7831 492 15 1 0 yes Riyadh 7832 370 148 29 32 9 4 0 no Grasse 7835 1755 253 19 11 2 16 21 3 1 yes Potsdam 7836 1814 320 17 4 16 12 1 1 yes Shanghai 7837 649 168 61 28 9 60 24 4 0 yes Simosato 7838 419 99 8 48 11 28 18 1 0 no Graz 7839 2056 554 172 9 2 11 7 1 1 yes Herstmonceux 7840 2798 881 402 17 3 11 7 1 1 yes Orroral 7843 2293 647 437 11 2 19 10 2 1 yes Greenbelt (M6) 7918 50 17 27 10 2 1 0 yes Matera 7939 1302 306 160 34 38 21 1 1 yes Wettzell 8834 1893 679 640 13 3 18 9 1 0 no [Mailed From: ”Van S. Husson” ******************************************************************************** |