| Date: | 2005-08-04 13:15:00 | |
| Sender: | Ron Noomen <Ron Noomen <ron@astro.lr.tudelft.nl>> | |
| Subject: | [SLR-Report] No. 5761: Delft QL Report August 04, 2005 | |
| Author: | Ron Noomen | |
| Content: | ******************************************************************************** SLR Electronic Report 2005-08-04 13:15:00 UTC Message No. 5761 ******************************************************************************** Author: Ron Noomen Subject: Delft QL Report August 04, 2005 WEGENER-2 IERS REPORT OF THE QUICK-LOOK DATA ANALYSIS CENTER DELFT UNIVERSITY OF TECHNOLOGY FACULTY OF AEROSPACE ENGINEERING THE NETHERLANDS August 4, 2005 This is a daily report, presenting the results of a continuing analysis of the most recent global LAGEOS-1 and LAGEOS-2 quick-look laser ranging data. The report consists of (A) a pass summary, (B) an overview of the analysis results, detailed statistics of the analysed measurements, and an accumulative pass overview and (C) the earth rotation parameter solutions submitted to IERS. The report is based on all quick-look data as received until Thu, Aug 4, 2005. Questions and comments should be addressed to: R. Noomen Delft University of Technology Faculty of Aerospace Engineering Delft Institute for Earth-Oriented Space Research Kluyverweg 1 2629 HS Delft The Netherlands Telephone: +31-15-2785377 Telefax : +31-15-2785322 E-mail : ron.noomen@deos.tudelft.nl A. PASS SUMMARY The table below gives an overview of the ranging data both on LAGEOS-1 and LAGEOS-2, as received by the Quick-Look Data Analysis Center (QLDAC) on Thu, Aug 4, 2005. All data were obtained through the NASA Crustal Dynamics Data Information system (CDDIS) and the Eurolas Data Center (EDC) in Germany. The data are unscreened and may span more than a week due to late reporting by the stations. ------------------------------------------------------------------------------ Station System/Location Period No. of Passes ID LAGEOS-1 LAGEOS-2 ------------------------------------------------------------------------------ 1864 Maidanak, Uzbekistan (site 2) 050802 - 050803 2 - 1884 Riga, Latvia 050802 - 050802 1 - 1893 Kazivili, Crimea, Ukraine 050801 - 050801 1 - 6810 Zimmerwald 846, Switzerland 050803 - 050804 1 3 7080 McDonald Obs., Fort Davis, TX 050803 - 050803 1 - 7090 Yarragadee, Australia 050802 - 050803 2 3 7105 Greenbelt, Maryland 050803 - 050803 2 - 7110 Monument Peak, California 050802 - 050803 2 1 7237 Changchun, China 050803 - 050803 1 - 7810 Zimmerwald 423, Switzerland 050803 - 050804 1 3 7811 Borowiec, Poland 050802 - 050802 1 - 7824 San Fernando, Spain 050802 - 050803 2 - 7825 Mount Stromlo, Australia 050801 - 050803 8 6 7832 Riyad, Saudi Arabia 050803 - 050803 3 3 7838 Simosato Observatory, Japan 050803 - 050803 1 1 7839 Graz, Austria 050802 - 050803 3 2 7840 Herstmonceux, United Kingdom 050802 - 050804 10 5 8834 Wettzell, Germany 050803 - 050804 2 - ------ ------ --- --- TOTAL 050801 - 050804 44 27 ------------------------------------------------------------------------------ B. ANALYSIS RESULTS The analysis is based on two orbit solutions using global quick-look normal points that cover a period of 8 days which are computed simultaneously. This week´s data interval runs from Wed, Jul 27, 2005 to Thu, Aug 4, 2005. The measurement and dynamic models used in this analysis are close to the IERS Standard. The overall model is referred to as QLDACMOD11. The details of this model can be obtained on request. The terrestrial reference frame is provided by the ITRF2000 station coordinates solution (extended with coordinates of new stations, where necessary). The general statistics and results of this week´s analysis are thus: ----------------------------------------------------------------------- Satellite LAGEOS-1 LAGEOS-2 Number of Stations 0 0 Number of Passes 0/ 0 0/ 0 Number of Normal Points 0/ 0 0000/ 0 Weighted RMS of Fit (mm) 0 0 ----------------------------------------------------------------------- Residual statistics per station. The header line for each station shows the station id, its name, whether the position is solved for or not and the measurement accuracy in mm. Rejected observations are not used for the calculation of the rms-of-fit, the biases or the scatter. The latter holds w.r.t. the residual trend line described by the bias estimates. Uncertainties are 3-sigma values. -------------------------------------------------------------------------------- Date Time Sat. Obs. RMS Range Bias Time Bias Scatter tot/rej (mm) (mm) (us) (mm) -------------------------------------------------------------------------------- Distribution of daytime, nighttime and twilight passes since Jan 1, 2003: -------------------------------------------------------------------------- Station System Period Number of Passes LAGEOS-1 LAGEOS-2 Day/Night/Twil. Day/Night/Twil. Total -------------------------------------------------------------------------- 1824 KIEVLA 050112 - 050404 0/ 9/ 0 0/ 14/ 0 23 1831 LVIL 050117 - 050718 0/ 27/ 0 0/ 20/ 0 47 1864 MD2LAS 050110 - 050803 0/ 66/ 0 0/ 46/ 0 112 1873 SIMLAS 050316 - 050802 0/ 24/ 0 0/ 14/ 0 38 1884 RIGLAS 050104 - 050802 0/ 38/ 0 3/ 42/ 3 86 1893 CRMLAS 050731 - 050801 0/ 2/ 0 0/ 0/ 0 2 6405 TIGO 050104 - 050706 7/ 18/ 2 8/ 21/ 2 58 6810 ZIMLAT 050101 - 050804 194/111/ 20 154/ 70/ 17 566 7080 MLRS25 050101 - 050803 36/ 63/ 4 25/ 67/ 8 203 7090 ML0514 050101 - 050803 110/350/ 27 105/247/ 21 860 7105 ML0725 050108 - 050803 1/ 38/ 3 13/ 54/ 5 114 7110 ML0414 050118 - 050803 80/107/ 17 40/103/ 10 357 7124 ML0819 050118 - 050622 0/ 29/ 0 0/ 9/ 0 38 7237 CHALAS 050102 - 050803 0/ 60/ 1 0/ 71/ 0 132 7249 BEJLAS 050101 - 050705 0/ 55/ 0 0/ 69/ 0 124 7308 CRLLAS 050111 - 050510 7/ 5/ 1 1/ 10/ 0 24 7355 TROS02 050603 - 050801 0/ 34/ 0 0/ 7/ 0 41 7405 TIGO 050105 - 050705 5/ 26/ 0 3/ 7/ 0 41 7501 ML0616 050117 - 050721 40/110/ 3 40/ 87/ 7 287 7806 METLAS 050301 - 050301 0/ 0/ 0 0/ 1/ 0 1 7810 ZIMLAT 050101 - 050804 173/110/ 18 149/ 64/ 16 530 7811 POLLAS 050111 - 050802 0/ 46/ 0 0/ 39/ 0 85 7824 SPNLAS 050108 - 050803 4/ 93/ 0 1/ 92/ 3 193 7825 STL3 050101 - 050803 212/310/ 30 176/204/ 23 955 7832 SALRO 050101 - 050803 72/169/ 12 104/174/ 19 550 7835 GRASSE 050104 - 050705 0/ 32/ 2 0/ 33/ 3 70 7837 CHILAS 050102 - 050414 0/ 22/ 0 0/ 40/ 1 63 7838 SHOLAS 050106 - 050803 46/ 64/ 1 25/ 77/ 4 217 7839 AUSLAS 050103 - 050803 150/104/ 13 92/ 90/ 13 462 7840 RGOLAS 050102 - 050804 176/102/ 21 122/ 90/ 20 531 7841 GFZLA3 050105 - 050802 43/ 40/ 10 17/ 61/ 8 179 7848 FTLR06 050515 - 050719 4/ 30/ 0 3/ 10/ 0 47 7941 MLROnn 050102 - 050725 49/ 84/ 5 70/ 92/ 18 318 8834 WLRS01 050109 - 050804 156/111/ 17 129/103/ 19 535 -------------------------------------------------------------------------- C. EARTH ROTATION PARAMETER SOLUTIONS FOR IERS The following solutions for the polar motion and the UT1-UTC time difference were also obtained in the 10-day data arc analysis described in the previous section. Only solutions submitted to IERS are presented here. D. COMMENTS 1. The analysis covered in this report is based on a new set of station coordinates: instead of the solution SSC(DUT)93L05, which was extrapolated over some 10 years beyond the epoch of the latest observations, the current analysis relies on the ITRF2000 solution. Tests performed during the last year show that the rms-of-fit that can be obtained when using ITRF2000 can be reduced to about 2 cm (instead of the 3+ cm which was achieved with the old model, for present-day epochs). Other model modifications are to be expected. We hope to serve the community with this development. 2. As of July 1, 2003, a new computation model and analysis strategy are in use: in terms of geometric modeling, models for ocean loading and atmospheric pressure loading have been turned on. The frequency of the solutions for the Earth Orientation Parameters has been increased to once per day (rather than once per 3 days). As a consequence, the arc length has been changed from 10 days to 8 days. Also, the empirical accelerations acting on the spacecraft are estimated twice per arc (i.e. for 4-day periods). To absorb (unmodeled) geocenter motion, 3 coefficients of the gravity field model are estimated: C(1,0), C(1,1) and S(1,1). Finally, the overall weighting scheme for the individual SLR observations is also modified slightly. 3. As of the same date, provisions for handling the dual-wavelength systems 7405 and 7810 properly have been installed. This is done by introducing dummy station ids 6405 and 6810 for the observations taken on 2nd wavelength. The specific analysis results are easily recognizable because the wavelength has been added to the printout of the station name. 4. As of July 7, 2004, similar provisions for handling the dual-wavelength syste 7941 properly have been installed. This is done by introducing a dummy station id 6941 for the observations taken on 2nd wavelength. From: Ron Noomen ******************************************************************************** |