From Geodetic Thu Dec 9 05:26:36 1993 From: Geodetic (Geodetic) Date: Thu, 9 Dec 1993 5:26:36 PST Subject: [IGSREPORT-0647] Message-ID: ****************************************************************************** IGS Electronic Report Thu Dec 9 5:26:36 PST 1993 Message Number 0647 ****************************************************************************** Author: Geodetic Survey of Canada Subject: Subject: EMR Analysis Report (week 725) (Nov 28 - Dec 04,93) Our analysis utilizes the JPL GIPSY/OASIS II (UNIX) software system and data from all (up to 7) Canadian stations augmented by up to 12, globally distributed, core stations (see Table 1 for the list of stations). This effort is a part of a joint pilot project called "Active Control System" and involves the Geodetic Survey Division (GSD), SMRSS; the Geophysics Division and Pacific Geoscience Centre of the Geological Survey of Canada, all three institutions are part of the Department of Energy, Mines & Resources (EMR). Table 1 : Station Summary (also indicated are day no. for which a particular station is not included in the daily solution, either due to being down or data being late). STATION IGS code MISSING DAY NO. 1993 Albert Head, CAN ALBH Algonquin, CAN ALGO* Fairbanks FAIR* Goldstone GOLD* Hartebeesthoek HART* Holberg,CAN HOLB 335 Kokee Park KOKB Madrid MADR* McMurdo MCMU* 332 to 335 Pamatai PAMA 334, 335, 338 Penticton, CAN DRAO Santiago SANT* St. Johns, CAN STJO Canbera TIDB* Tromsoe TROM* Wettzell WETT* Yarragadee YAR1* Yellowknife, CAN YELL* 338 * indicates constrained stations, remaining are solved for (50m apriori sig.) SOLUTION CHARACTERISTICS Reference frame and orientation: Nominally ITRF91, at epoch 1992.5 is realized by constraining up to 12 of the above stations at the IGS coordinates (see IGS message #90). Orientation is realized through the above coordinates and, once a week, the fixed DUT1 values from the current NEOS/IERS (Bull. A). Constants and models: - no change, see the IGS mess. #101 for details. Estimation strategies: - no change, see the IGS mess. #101 for details - , except for the estimation of DUT1, stochastic orbit modeling, new weighting of L3,P3, see IGS mess. #130. ALGO was used as time reference. Aposteriori variance factors typically are between 0.5 and 1.0 (noise about 3mm and 200mm for phase and smoothed pseudorange observations, resp.). PRODUCTS GENERATED: The following products are generated and uploaded into CDDIS @ NASA/GSFC EMR07250-6.EPH GPS ephem. files for days 0-6, week #725 in sp3 format EMR07257.ERP pole x,y and DUT1 solutions for week #725 EMR07257.SUM name of this text summary file REMARKS on EMR's products: 1. ALGO hydrogen maser used as a time reference. In the sp3 EPH file sat. epochs with no reference (e.g. ALGO not observing a satellite) have a value of 99999. microseconds. ALGO clock error & drift were about -1275 ns (49319) & -18 ns/day w.r.t. GPS time. 2. Starting with the week #720 we are assigning nominal sigma codes of 8(256mm) for all the orbits passing our quality analysis. For errors larger than 1.5m we are assigning sigmas of abs(error)/4, expressed by the binary exponent in the sp3 header. 3. Only 50% or less data for PRN13 (GPS9) for all days during this week. 4. For PRN9 (GPS39) on Dec.02 and 03 (day336 and 337) experienced modelling problems, sp3 accuracy codes changed accordingly for this sv. 5. PRN25 was not tracked on Dec.02 (day336).