[IGSREPORT-78] EMR Analysis report (week 0677)

[Jan]

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IGS Electronic Report      7-JAN-1993 19:15:57       Message Number 78
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From:     Jan Kouba 
Subject:  EMR Analysis report (week 0677)
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-- 
Jan Kouba
Geodetic Survey of Canada
Ottawa, Ontario, Canada
Internet: kouba at geod.emr.ca

    Subject: Geodetic Survey Division (GSD), SMRSS, EMR analysis results
             for the GPS week # 677 (Dec. 28, 1992 to Jan. 02, 1993)

    Submitted by:
       J. Kouba **, P. Tetreault, R. Ferland, F. Lahaye, P. Heroux, L. Mancuso

    Geodetic Survey Division (GSD), Surveys Mapping & Remote Sensing Sector
    (SMRS), Energy Mines and Resources (EMR), 615 Booth Str., Ottawa, K1A 0E3
     **  on secondment to the Geodetic Survey from the Geophysics Div.
         Geological Survey of Canada (GSC), EMR, 1 Observatory Crescent,
	 Ottawa, K1A 0Y3

      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).  
Submitted results include only days when AS was not invoked
      This effort is a part of a joint pilot project to test the
so called "Active Control System" in Canada 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). 
                                       MISSING DAY NO.
   STATION            IGS code         1992  /  1993
Albert Head, CAN       ALBH
Algonquin, CAN         ALGO*        
Fairbanks              FAIR*            
Goldstone              GOLD*                
Hartebeesthoek         HART*        
Holberg,CAN            HOLB
Kokee Park             KOKB            362-366 / 001, 002 
Madrid                 MADR*           
McMurdo                MCMU*           
Pamatai                PAMA          
Penticton, CAN         DRAO 
Santiago               SANT*             
St. Johns, CAN         STJO
Canbera                TIDB*                         
Tromsoe                TROM*           366     / 001
Wettzell               WETT*           362
Yarragadee             YAR1*           363 
Yellowknife, CAN       YELL*                   / 001
* indicates constrained stations, remaining are solved for (50m apriori sig.)

SOLUTION CHARACTERISTICS

Reference frame and orientation:
      Nominally ITRF91 at epoch 1992.5, realized by constraining up to 11 
above stations at the IGS coordinates (see IGS message #90): 
orientation is realized through the above coordinates and the fixed, once a 
week, 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.                           
      Aposterioi variance factors typically are between 0.5 and 1.0 (noise 
about 3mm and 200mm for phase and smoothed pseudorange observations, resp.). 
      Due to data quality for the AS days the results for the corresponding 
days (with AS turned on) are not included here. 

PRODUCTS GENERATED:
The following products are generated and uploaded into CDDIS @ NASA/GSFC
   EMR06777.EPH        GPS ephem. for week # 677 in sp3 format
   EMR06777.ERP        pole x,y and DUT1 solutions for week # 677
   EMR06777.SUM        name of this text 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 -735 ns (48983) and -35 ns/day 
   w.r.t. GPS time.  ALGO clock was reset to 0 ns on Dec 30, 16:32:00.
2. KOKB was not used.
3. PRN 29 was first tracked on 92dec31.  PRN 29 was deleted from processing 
   on Dec 31, 1992 to Jan 02, 1993.