Subject: [IGSREPORT-4174] Wk 0920 G-SINEX Comparisons
From: AC Coordinator / NRCan GSDivision
Date: Fri, 26 Sep 1997 8:55:52 PDT

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IGS Electronic Report    Fri Sep 26  8:55:52 PDT 1997      Message Number 4174
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Author: AC Coordinator / NRCan GSDivision
Subject: Wk 0920 G-SINEX Comparisons

Comparison of GNAAC Combined SINEX Solutions - Week 0920   
(AUG 24, 1997 - AUG 30, 1997)

Contacts: J. Kouba ([email-masked])
          D. Hutchison([email-masked])

COMPARISON ALGORITHM:

   1. MIT and NCL GNAAC  combined  SINEX  solutions  for the week in question
      were deconstrained. The JPL SINEX file is already unconstrained.

   2. Any stations  not  present  in  all GNAAC combined SINEX files were de-
      leted  from all three combined solutions.  Every solution was then sub-
      jected to a 7-parameter transformation  into  a common reference system
      (the 13 ITRF94 station positions). 

   3. Outliers are determined at the 99.0% confidence level for each coordin-
      ate.  If a station  has  an outlier in either latitude,  longitude,  or
      height, it is ignored in all subsequent computations.

FILES COMPARED:
   mit0920g.snx at cddis.gsfc.nasa.gov
   jpl0920g.snx at cddis.gsfc.nasa.gov
   ncl0920g.snx at cddis.gsfc.nasa.gov

GNAACs: MIT JPL NCL

STATIONS WITH INCONSISTENT ANTENNA ECCENTRICITY INFORMATION:
(FILE: / STATION / L1 (UNE) / L2 (UNE) / ECCENTRICITY (UNE))
(UNE = Up North East (metres))

jpl0920g.snx: BISH    .075   .002  -.001   .069  -.001   .002   .046   .000   .000
mit0920g.snx: BISH    .078   .000  -.003   .074  -.003  -.001   .046   .000   .000
jpl0920g.snx: CRO1    .110   .000   .000   .128   .000   .000   .081   .000   .000
mit0920g.snx: CRO1    .110   .000   .000   .128   .000   .000  -.032   .000   .000
ncl0920g.snx: CRO1    .110   .000   .000   .128   .000   .000   .081   .000   .000
jpl0920g.snx: HARK    .110   .000   .000   .128   .000   .000  9.754   .000   .000
mit0920g.snx: HARK    .110   .000   .000   .128   .000   .000  9.803   .000   .000
ncl0920g.snx: HARK    .110   .000   .000   .128   .000   .000  9.803   .000   .000
jpl0920g.snx: LMNO    .110   .000   .000   .128   .000   .000   .000   .000   .000
mit0920g.snx: LMNO    .110   .000   .000   .128   .000   .000  -.008   .000   .000
jpl0920g.snx: LPGS    .110   .000   .000   .128   .000   .000   .000   .000   .000
mit0920g.snx: LPGS    .110   .000   .000   .128   .000   .000   .046   .000   .000
ncl0920g.snx: LPGS    .110   .000   .000   .128   .000   .000   .046   .000   .000
jpl0920g.snx: MDVO    .078   .000  -.003   .074  -.003  -.001   .146   .000   .000
mit0920g.snx: MDVO    .078   .002  -.003   .074  -.003  -.001   .146   .000   .000
ncl0920g.snx: MDVO    .078   .000  -.003   .074  -.003  -.001   .149   .000   .000
jpl0920g.snx: PENC    .110   .000   .000   .128   .000   .000   .000   .000   .000
mit0920g.snx: PENC    .110   .000   .000   .128   .000   .000   .022   .000   .000
jpl0920g.snx: SELE    .110   .000   .000   .128   .000   .000   .000   .000   .000
mit0920g.snx: SELE    .110   .000   .000   .128   .000   .000   .091   .000   .000
jpl0920g.snx: TAEJ    .075   .002  -.001   .069  -.001   .002   .660   .000   .000
mit0920g.snx: TAEJ    .075   .002  -.001   .069  -.001   .002   .660   .000   .000
ncl0920g.snx: TAEJ    .078   .000  -.003   .074  -.003  -.001   .660   .000   .000
jpl0920g.snx: ZIMM    .069   .000   .000   .068   .000   .000   .000   .000   .000
mit0920g.snx: ZIMM    .078   .000  -.003   .074  -.003  -.001   .000   .000   .000

ANTENNA PHASE CENTRE CONFLICTS IN FILE ncl0920g.snx                             
   ASC1 Missing Antenna      
   AUCK Missing Antenna      
   CHAT Missing Antenna      
   DGAR Missing Antenna      
   KIRU Missing Antenna      
   KWJ1 Missing Antenna      
   MKEA Missing Antenna      
   VILL Missing Antenna      
 
SITES AFFECTED BY ABOVE CONFLICTS, NON-FIDUCIAL SITES SUBSEQUENTLY EXCLUDED:
   Stations: ASC1 AUCK CHAT DGAR KIRU KWJ1 MKEA VILL 

CONFIDENCE  LEVEL  FOR OUTLIER DETECTION: 99%
OUTLIERS REJECTED (COORD/STATION/GNAACs):
   Lon MALI MIT-JPL   Hgt MCM4 JPL-NCL   Hgt MCM4 MIT-JPL
   Hgt IISC MIT-JPL   Hgt KOUR MIT-JPL   Hgt WUHN MIT-JPL
   Hgt KOUR MIT-NCL   Hgt WUHN MIT-NCL     

47 GLOBAL STATIONS:
   ALBH ALGO ANKR AREQ BAHR BOR1 BRAZ BRMU BRUS CAS1
   DRAO FAIR FORT GOLD GUAM HOB2 IRKT KELY KERG KIT3
   KOKB KOSG LHAS MAC1 MATE MDO1 METS NLIB NYAL ONSA
   PERT POTS RCM6 REYK SANT SHAO STJO TAHI TAIW TIDB
   TSKB USUD WES2 WHIT WTZR YELL ZWEN   

9 FIDUCIAL STATIONS:
   ALGO FAIR GOLD KOKB KOSG SANT TIDB WTZR YELL 

AVERAGE COORDINATE RMS:

             47    GLOBAL  STATIONS          9   FIDUCIAL   STATIONS
        MIT-JPL   MIT-NCL   JPL-NCL MIT-ITRF94 JPL-ITRF94 NCL-ITRF94
           (mm)      (mm)      (mm)       (mm)       (mm)       (mm)
        -------   -------   ------- ---------- ---------- ----------
Lat        1.2       1.0       0.9        5.3        4.7        4.7 
Lon        2.4       1.7       2.5        7.9        7.3        7.5 
Hgt        2.5       2.5       1.7        9.7       10.0       10.2 
3D         3.7       3.2       3.1       13.6       13.2       13.5

VARIANCE FACTORS (CHI-SQUARE / (DEGREES OF FREEDOM)):

        47    GLOBAL  STATIONS          9   FIDUCIAL   STATIONS
   JPL-NCL   MIT-JPL   MIT-NCL MIT-ITRF94 JPL-ITRF94 NCL-ITRF94
   -------   -------   ------- ---------- ---------- ----------
     0.058     0.639     0.166      1.333      0.979      0.938

OFFSETS AND SCALE FACTOR WRT ITRF94 (FIDUCIAL STATIONS):
(TRANSFORMATION FROM ITRF94 TO GNAAC SINEX FILES)

      Tx (mm) STD(mm) Ty (mm) STD(mm) Tz (mm) STD(mm) Scale (ppb) STD(ppb)
      ------- ------- ------- ------- ------- ------- ----------- --------
JPL      -5.6     4.6    13.4     4.8   -24.5     6.8        -1.6      0.5
MIT      -5.8     3.1    11.3     3.3   -28.4     3.6        -1.5      0.4
NCL      -0.2     5.0    19.9     5.3   -13.4     7.3        -1.5      0.5

REMARKS:

THE FOLLOWING FIDUCIAL STATIONS ARE MISSING FROM mit0920g.snx :
   Stations: HART TROM YAR1

THE FOLLOWING FIDUCIAL STATIONS ARE MISSING FROM jpl0920g.snx :
   Stations: TROM YAR1

THE FOLLOWING FIDUCIAL STATIONS ARE MISSING FROM ncl0920g.snx :
   Stations: HART TROM YAR1

MADR WAS NOT USED IN GLOBAL COMPARISON DUE TO LARGE COORDINATE DIFFERENCES
WITH ITRF94, DESCRIBED BELOW:

STATION / GNAAC / LONGITUDE DIFFERENCE (mm.):
   MADR JPL -28.6
        MIT -29.3
        NCL -31.9

-- 
David Hutchison
Geodetic Survey of Canada
Ottawa, Ontario, Canada
Internet: [email-masked]

[Mailed From: David Hutchison <[email-masked]>]