[IGSREPORT-333] EMR Analysis Report (week 700)

[J.]

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IGS Electronic Report     18-JUN-1993 10:49:17       Message Number 333
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From: J. Kouba
Subj: EMR Analysis Report (week 700)
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					          (Jun 06 - Jun 12,93)

      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*            163
Hartebeesthoek         HART*            
Holberg,CAN            HOLB             
Kokee Park             KOKB              
Madrid                 MADR*            159, 163
McMurdo                MCMU*            160   
Pamatai                PAMA             157 to 163 
Penticton, CAN         DRAO             159
Santiago               SANT*              
St. Johns, CAN         STJO             159 to 162
Canbera                TIDB*            157, 163 
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
   EMR07000-6.EPH       GPS ephem. files for days 0-6, week # 700 in sp3 format 
   EMR07007.ERP        	pole x,y and DUT1 solutions for week # 700
   EMR07007.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 +270 ns (49144) & 15 ns/day w.r.t.
   GPS time.  
2. AS was on from Jun06-09.  Orbit and EOP solutions affected by AS. 
   Orbit errors up to 4.5m. AS pseudoranges weighted with 100m sigma. 
   No DUT1 estimation on AS days.
3. STJOHNS was rejected by the processing, for days Jun08-11. This was due to
   a wrong RINEX header caused  by an operator error initilizing the cmp_RINEX
   conversion. The problem was corrected on Jun 16 and files corrected on CDDIS
4. DRAO not used on June 8 due to problems with data.