[IGSREPORT-296] EMR Analysis Report (week 697)

[J.]

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IGS Electronic Report     27-MAY-1993 08:19:12       Message Number 296
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From:  J. Kouba
Subj: EMR Analysis Report (week 697)
-------------------------------------
					          (May 16 - May 22,93)
    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 0E9
     **  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).  

      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). 
                               
   STATION            IGS code       MISSING DAY NO. 1993
Albert Head, CAN       ALBH            
Algonquin, CAN         ALGO*        
Fairbanks              FAIR*                              
Goldstone              GOLD*            141, 142 
Hartebeesthoek         HART*            141, 142 
Holberg,CAN            HOLB            
Kokee Park             KOKB             139 
Madrid                 MADR*            141, 142 
McMurdo                MCMU*                
Pamatai                PAMA             136 to 142 
Penticton, CAN         DRAO             
Santiago               SANT*              
St. Johns, CAN         STJO       
Canbera                TIDB*            141, 142     
Tromsoe                TROM*            
Wettzell               WETT*          
Yarragadee             YAR1*           
Yellowknife, CAN       YELL*            
* 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
   EMR06970-6.EPH       GPS ephem. files for days 0-6, week # 697 in sp3 format 
   EMR06977.ERP        	pole x,y and DUT1 solutions for week # 697
   EMR06977.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 +25 ns (49123) &  25 ns/day w.r.t.
   GPS time.  ALGO clock reset at 01:15 on 49127 (0 ns).
2. PRN29 was excluded from orbit processing due to repositionning, on May 20. 
3. PRN7 was tracked by some receivers on May 22, but deleted from processing.
4. No ALGO data between May 19 18:45 and May 20 01:15 due to SLR observations
at the GPS pillar.