[IGSREPORT-406] EMR Analysis Report (706)

[Jan]

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IGS Electronic Report     29-JUL-1993 08:44:54       Message Number 406
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From: Jan Kouba 
Subj: EMR Analysis Report (706)
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					          (Jul 18 - Jul 24,93)

      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*             199 
Hartebeesthoek         HART*             202, 203
Holberg,CAN            HOLB             
Kokee Park             KOKB              203, 204
Madrid                 MADR*             199
McMurdo                MCMU*             199, 204, 205
Pamatai                PAMA              199 to 205 
Penticton, CAN         DRAO             
Santiago               SANT*             202, 204 
St. Johns, CAN         STJO             
Canbera                TIDB*             199 
Tromsoe                TROM*            
Wettzell               WETT*            
Yarragadee             YAR1*             201, 204      
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
   EMR07060-6.EPH       GPS ephem. files for days 0-6, week # 706 in sp3 format 
   EMR07067.ERP        	pole x,y and DUT1 solutions for week # 706
   EMR07067.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 -140 ns (49186) & -60 ns/day w.r.t.
   GPS time.  
2. Modelling with PRN1 (SVN32) on jul 19 & 20, errors of 10 m & 9 m;
   and on jul24 with PRN21, errors of 5 m.   
3. PRN9 was introduced in the orbit processing on jul 22 (day203).