[IGSREPORT-434] EMR Analysis Report (week 708)

[Jan]

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IGS Electronic Report     12-AUG-1993 21:38:24       Message Number 434
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From: Jan Kouba
Subj: EMR Analysis Report (week 708)
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					          (Aug 01 - Aug 07,93)

      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*             215
Fairbanks              FAIR*                              
Goldstone              GOLD*             218 
Hartebeesthoek         HART*             
Holberg,CAN            HOLB               
Kokee Park             KOKB              
Madrid                 MADR*             
McMurdo                MCMU*             
Pamatai                PAMA              213 to 219 
Penticton, CAN         DRAO             
Santiago               SANT*             
St. Johns, CAN         STJO             
Canbera                TIDB*             
Tromsoe                TROM*            
Wettzell               WETT*            
Yarragadee             YAR1*             218       
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
   EMR07080-6.EPH       GPS ephem. files for days 0-6, week # 708 in sp3 format 
   EMR07087.ERP        	pole x,y and DUT1 solutions for week # 708
   EMR07087.SUM		name of this text summary file 


REMARKS on EMR's products:
1. FAIR maser used as a time reference for Aug02-03/93 due to data gaps
   at ALGO (caused by power failures and restarting problems)
2. 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 -230 ns (49200) & -20 ns/day w.r.t.
   GPS time.  
3. PRN15 was removed from the orbit processing on Aug 02 (day214) due to 
   maintainance/orbit repositioning

-- 
Jan Kouba
Geodetic Survey of Canada
Ottawa, Ontario, Canada
Internet: kouba at geod.emr.ca