| Date: | 1998-04-29 14:00:00 | |
| Sender: | Van S. Husson <[Mailed Van S. Husson <dsgvsh@slral2.atsc.allied.com>]> | |
| Subject: | [SLR-Mail] No. 115: 3rd Global Performance Report Card (April 1, 1997 - March 31, 19 | |
| Author: | Van S. Husson | |
| Content: | ******************************************************************************** SLR Electronic Mail 1998-04-29 14:00:00 UTC Message No. 115 ******************************************************************************** Author: Van S. Husson Subject: 3rd Global Performance Report Card (April 1, 1997 - March 31, 19 This is the third SLR global performance report card for the period (April 1, 1997 through March 31, 1998). 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 (April 1, 1997 through March 31, 1998) 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 230 237 246 8 21 24 2 0 no Komsomolsk 1868 195 85 94 13 2 0 no Mendeleevo 1870 246 3 0 no Simeiz 1873 154 25 51 25 1 0 no Riga 1884 518 131 30 34 8 31 23 1 1 no Katsively 1893 64 17 31 52 8 3 1 no Cuba 1953 167 1 1 no McDonald 7080 1568 484 403 16 3 10 8 1 1 yes Yarragadee 7090 2969 979 1116 9 2 11 4 1 0 yes Greenbelt (M7) 7105 3500 872 455 9 2 16 8 2 0 yes Monument Peak 7110 5462 1411 1036 11 2 10 4 2 0 yes Tahiti (M8) 7124 126 67 22 30 4 26 2 0 yes Haleakala 7210 1958 648 546 14 3 14 8 1 0 yes Wuhan 7236 160 42 14 43 115 2 0 no Changchun 7237 2219 468 220 15 8 23 18 2 1 yes Beijing 7249 1256 143 36 48 27 102 21 1 0 no Tokyo 7308 230 55 30 37 14 25 1 1 yes Arequipa 7403 1811 347 8 3 13 6 1 0 yes Cagliari 7548 162 42 52 22 1 0 no Metsahovi 7805 616 1 1 no Metsahovi2 7806 122 14 24 7 20 1 1 no Zimmerwald 7810 749 235 25 27 6 13 26 1 1 yes Borowiec 7811 561 131 8 32 6 14 13 1 1 yes San Fernando 7824 1334 205 73 16 52 19 1 0 yes Helwan 7831 492 15 1 0 yes Riyadh 7832 178 46 4 32 9 5 0 no Grasse 7835 1694 449 27 10 2 14 18 1 1 yes Potsdam 7836 1787 328 17 4 17 11 1 1 yes Shanghai 7837 661 195 50 29 8 72 29 6 0 yes Simosato 7838 351 61 7 45 8 19 16 1 0 no Graz 7839 2107 592 166 9 2 8 6 1 1 yes Herstmonceux 7840 2782 876 413 17 3 10 6 1 1 yes Orroral 7843 2765 821 590 11 2 22 8 1 1 yes Matera 7939 1047 340 160 34 31 21 1 1 yes Wettzell 8834 2022 675 614 18 4 21 7 1 0 yes New mail has arrived. [Mailed From: ”Van S. Husson” ******************************************************************************** |