[IGSREPORT-325] EMR Analysis Report (week 699)

[Jan]

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IGS Electronic Report     10-JUN-1993 16:13:03       Message Number 325
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From: Jan Kouba
Subj: EMR Analysis Report (week 699)
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					          (May 30 - Jun 05,93)

      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*            155 
Holberg,CAN            HOLB             
Kokee Park             KOKB              
Madrid                 MADR*            
McMurdo                MCMU*            150,151,153    
Pamatai                PAMA             150 to 156 
Penticton, CAN         DRAO             
Santiago               SANT*            150,151  
St. Johns, CAN         STJO       
Canbera                TIDB*            
Tromsoe                TROM*            153, 154
Wettzell               WETT*            155 
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
   EMR06990-6.EPH       GPS ephem. files for days 0-6, week # 699 in sp3 format 
   EMR06997.ERP        	pole x,y and DUT1 solutions for week # 699
   EMR06997.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 +70 ns (49137) &  6 ns/day w.r.t.
   GPS time.  
2. AS was on all day Jun 05. Orbit and EOP solutions affected by AS. 
   Orbit errors up to 2.5m on this day. AS pseudoranges weighted with
   100m sigma.
3. PRN31 was excluded from orbit processing due to noisy data, from May31 
   to Jun02, inclusive.
4. PRN7 was tracked by some receivers, but deleted from processing.
5. MCMU deleted from processing on June 02, 93 due to data problems.