| Date: | 2005-02-06 13:15:00 | |
| Sender: | Ron Noomen <Ron Noomen <ron@astro.lr.tudelft.nl>> | |
| Subject: | [SLR-Report] No. 4898: Delft QL Report February 06, 2005 | |
| Author: | Ron Noomen | |
| Content: | ******************************************************************************** SLR Electronic Report 2005-02-06 13:15:00 UTC Message No. 4898 ******************************************************************************** Author: Ron Noomen Subject: Delft QL Report February 06, 2005 WEGENER-2 IERS REPORT OF THE QUICK-LOOK DATA ANALYSIS CENTER DELFT UNIVERSITY OF TECHNOLOGY FACULTY OF AEROSPACE ENGINEERING THE NETHERLANDS February 6, 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 Sun, Feb 6, 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 Sun, Feb 6, 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 ------------------------------------------------------------------------------ 1824 Kiev, Ukraine 050205 - 050206 - 2 6810 Zimmerwald 846, Switzerland 050205 - 050206 4 4 7237 Changchun, China 050205 - 050205 1 2 7810 Zimmerwald 423, Switzerland 050205 - 050206 4 4 7825 Mount Stromlo, Australia 050205 - 050205 5 3 7832 Riyad, Saudi Arabia 050204 - 050204 - 1 7841 Potsdam, Germany 050205 - 050206 2 1 8834 Wettzell, Germany 050205 - 050206 6 6 ------ ------ --- --- TOTAL 050204 - 050206 22 23 ------------------------------------------------------------------------------ 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 Sat, Jan 29, 2005 to Sun, Feb 6, 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 040701 - 050206 0/ 17/ 0 0/ 22/ 0 39 1831 LVIL 040815 - 050118 0/ 23/ 0 0/ 25/ 0 48 1864 MD2LAS 040701 - 050117 0/ 87/ 0 0/ 75/ 0 162 1873 SIMLAS 040703 - 040813 0/ 25/ 0 0/ 15/ 0 40 1884 RIGLAS 040712 - 050119 0/ 43/ 1 0/ 18/ 2 64 1893 CRMLAS 040705 - 041012 0/ 45/ 0 0/ 35/ 0 80 6405 TIGO 040710 - 050202 9/ 12/ 1 6/ 15/ 1 44 6810 ZIMLAT 040805 - 050206 179/112/ 19 106/103/ 18 537 7080 MLRS25 040701 - 050130 43/ 53/ 2 45/ 64/ 4 211 7090 ML0514 040716 - 050130 113/304/ 28 105/203/ 24 777 7105 ML0725 040701 - 050129 0/ 74/ 4 2/ 81/ 7 168 7110 ML0414 040701 - 050128 65/113/ 14 66/111/ 17 386 7124 ML0819 040705 - 050126 0/ 31/ 0 0/ 14/ 0 45 7231 WUHA01 040701 - 041208 0/ 8/ 0 0/ 20/ 0 28 7237 CHALAS 040702 - 050205 0/133/ 1 0/145/ 1 280 7249 BEJLAS 040701 - 050201 0/ 87/ 0 0/ 99/ 0 186 7308 CRLLAS 041201 - 050111 2/ 7/ 1 2/ 6/ 0 18 7355 TROS02 040702 - 040829 0/ 37/ 0 0/ 29/ 0 66 7405 TIGO 040710 - 050204 4/ 24/ 0 3/ 10/ 0 41 7501 ML0616 040701 - 050129 17/ 22/ 2 56/ 63/ 6 166 7604 BREF 041017 - 041021 0/ 1/ 0 0/ 2/ 0 3 7806 METLAS 040720 - 041203 0/ 16/ 0 0/ 10/ 0 26 7810 ZIMLAT 040701 - 050206 233/138/ 25 131/123/ 21 671 7811 POLLAS 040706 - 050121 0/ 50/ 0 0/ 59/ 0 109 7824 SPNLAS 040701 - 050204 0/ 91/ 0 0/ 84/ 0 175 7825 STL3 040807 - 050205 107/150/ 29 108/114/ 21 529 7832 SALRO 040702 - 050204 124/196/ 17 167/226/ 23 753 7835 GRASSE 040702 - 050203 0/ 43/ 1 0/ 29/ 1 74 7836 GFZLAS 040701 - 040701 0/ 1/ 0 0/ 0/ 0 1 7837 CHILAS 040704 - 050202 0/ 86/ 0 0/116/ 1 203 7838 SHOLAS 040701 - 050126 45/112/ 3 74/125/ 7 366 7839 AUSLAS 040701 - 050202 153/152/ 28 78/135/ 21 567 7840 RGOLAS 040701 - 050201 106/ 91/ 23 70/ 75/ 12 377 7841 GFZLA3 040702 - 050206 30/ 56/ 13 20/ 57/ 7 183 7845 GRASLL 040705 - 040920 11/ 14/ 0 3/ 12/ 1 41 7941 MLROnn 040701 - 050201 81/ 58/ 9 71/ 47/ 5 271 8834 WLRS01 040701 - 050206 188/124/ 22 112/129/ 17 592 -------------------------------------------------------------------------- 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 ******************************************************************************** |