Subject: [IGSREPORT-4313] Wk 0925 G-SINEX Comparisons
From: AC Coordinator / NRCan GSDivision
Date: Mon, 10 Nov 1997 13:48:42 PST

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IGS Electronic Report    Mon Nov 10 13:48:42 PST 1997      Message Number 4313
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Author: AC Coordinator / NRCan GSDivision
Subject: Wk 0925 G-SINEX Comparisons

Comparison of GNAAC Combined SINEX Solutions - Week 0925   
(SEP 28, 1997 - OCT 4, 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:
   mit0925g.snx at cddis.gsfc.nasa.gov
   jpl0925g.snx at cddis.gsfc.nasa.gov
   ncl0925g.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))

jpl0925g.snx: BISH    .075   .002  -.001   .069  -.001   .002   .046   .000   .000
mit0925g.snx: BISH    .078   .000  -.003   .074  -.003  -.001   .046   .000   .000
jpl0925g.snx: ELAT    .069   .000   .000   .068   .000   .000  -.011   .000   .000
mit0925g.snx: ELAT    .078   .000  -.003   .074  -.003  -.001  -.011   .000   .000
jpl0925g.snx: HARK    .110   .000   .000   .128   .000   .000  9.754   .000   .000
mit0925g.snx: HARK    .078   .000   .000   .096   .000   .000  9.803   .000   .000
ncl0925g.snx: HARK    .110   .000   .000   .128   .000   .000  9.803   .000   .000
jpl0925g.snx: KATZ    .069   .000   .000   .068   .000   .000  -.012   .000   .000
mit0925g.snx: KATZ    .078   .000  -.003   .074  -.003  -.001  -.012   .000   .000
jpl0925g.snx: LPGS    .110   .000   .000   .128   .000   .000   .000   .000   .000
mit0925g.snx: LPGS    .110   .000   .000   .128   .000   .000   .046   .000   .000
ncl0925g.snx: LPGS    .110   .000   .000   .128   .000   .000   .046   .000   .000
jpl0925g.snx: NICO    .110   .000   .000   .128   .000   .000   .000   .000   .000
mit0925g.snx: NICO    .110   .000   .000   .128   .000   .000   .050   .000   .000
jpl0925g.snx: SELE    .110   .000   .000   .128   .000   .000   .000   .000   .000
mit0925g.snx: SELE    .110   .000   .000   .128   .000   .000   .090   .000   .000
jpl0925g.snx: TAEJ    .075   .002  -.001   .069  -.001   .002   .660   .000   .000
mit0925g.snx: TAEJ    .075   .002  -.001   .069  -.001   .002   .660   .000   .000
ncl0925g.snx: TAEJ    .078   .000  -.003   .074  -.003  -.001   .660   .000   .000
jpl0925g.snx: TELA    .069   .000   .000   .068   .000   .000   .000   .000   .000
mit0925g.snx: TELA    .078   .000  -.003   .074  -.003  -.001   .000   .000   .000
jpl0925g.snx: ZIMM    .069   .000   .000   .068   .000   .000   .000   .000   .000
mit0925g.snx: ZIMM    .078   .000  -.003   .074  -.003  -.001   .000   .000   .000

ANTENNA PHASE CENTRE CONFLICTS IN FILE ncl0925g.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 MDO1 MIT-JPL   Lon NTUS MIT-JPL   Lon MDO1 MIT-NCL
   Lon NTUS MIT-NCL   Hgt THU1 JPL-NCL   Hgt WUHN MIT-JPL
   Hgt FORT MIT-JPL   Hgt HOB2 MIT-JPL   Hgt CAS1 MIT-NCL
   Hgt WUHN MIT-NCL   Hgt FORT MIT-NCL   Hgt HOB2 MIT-NCL

49 GLOBAL STATIONS:
   ALBH ALGO ANKR AREQ BAHR BOR1 BRAZ BRUS COCO CRO1
   DRAO FAIR GOLD GUAM IISC IRKT KELY KERG KIT3 KOKB
   KOSG KOUR KSTU LHAS MAC1 MALI MATE MCM4 METS NLIB
   ONSA PERT POL2 POTS RCM6 REYK SHAO STJO TAHI TAIW
   TIDB TSKB USUD WES2 WHIT WSRT WTZR YELL ZWEN 

8 FIDUCIAL STATIONS:
   ALGO FAIR GOLD KOKB KOSG TIDB WTZR YELL  

AVERAGE COORDINATE RMS:

             49    GLOBAL  STATIONS          8   FIDUCIAL   STATIONS
        MIT-JPL   MIT-NCL   JPL-NCL MIT-ITRF94 JPL-ITRF94 NCL-ITRF94
           (mm)      (mm)      (mm)       (mm)       (mm)       (mm)
        -------   -------   ------- ---------- ---------- ----------
Lat        2.1       2.0       0.8        2.8        2.1        2.3 
Lon        2.5       2.1       1.2        7.7        6.3        6.4 
Hgt        3.6       3.7       2.5        5.8        4.6        5.2 
3D         4.9       4.7       2.9       10.1        8.1        8.5

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

        49    GLOBAL  STATIONS          8   FIDUCIAL   STATIONS
   JPL-NCL   MIT-JPL   MIT-NCL MIT-ITRF94 JPL-ITRF94 NCL-ITRF94
   -------   -------   ------- ---------- ---------- ----------
     0.167     1.199     0.629      0.832      0.385      0.533

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      -1.2     4.4     3.0     4.9    -1.3     6.2        -2.0      0.5
MIT      -2.6     3.3     3.8     3.9     5.7     3.4        -2.1      0.5
NCL       2.3     4.4     4.7     4.9     9.0     5.5        -2.0      0.5

REMARKS:

EXPERIENCED SOME DIFFICULTY DECONSTRAINING FILE mit0925g.snx.

THE FOLLOWING FIDUCIAL STATIONS ARE MISSING FROM mit0925g.snx :
   Stations: HART TROM 

THE FOLLOWING FIDUCIAL STATIONS ARE MISSING FROM jpl0925g.snx :
   Stations: TROM 

THE FOLLOWING FIDUCIAL STATIONS ARE MISSING FROM ncl0925g.snx :
   Stations: HART TROM 

MADR, YAR1, SANT WERE NOT USED IN GLOBAL COMPARISON DUE TO LARGE COORDINATE DIFFERENCES
WITH ITRF94, DESCRIBED BELOW:

STATION / GNAAC / LONGITUDE DIFFERENCE (mm.):
   MADR JPL -27.0
        MIT -51.9
        NCL -28.3
   YAR1 MIT -34.0
   SANT MIT -33.2

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

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