Subject: [IGSREPORT-4294] Wk 0926 G-SINEX Comparisons
From: AC Coordinator / NRCan GSDivision
Date: Tue, 4 Nov 1997 7:41:09 PST

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IGS Electronic Report    Tue Nov  4  7:41:09 PST 1997      Message Number 4294
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Author: AC Coordinator / NRCan GSDivision
Subject: Wk 0926 G-SINEX Comparisons

Comparison of GNAAC Combined SINEX Solutions - Week 0926   
(OCT 5, 1997 - OCT 11, 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:
   mit0926g.snx at cddis.gsfc.nasa.gov
   jpl0926g.snx at cddis.gsfc.nasa.gov
   ncl0926g.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))

jpl0926g.snx: BISH    .075   .002  -.001   .069  -.001   .002   .046   .000   .000
mit0926g.snx: BISH    .078   .000  -.003   .074  -.003  -.001   .046   .000   .000
jpl0926g.snx: ELAT    .069   .000   .000   .068   .000   .000  -.011   .000   .000
mit0926g.snx: ELAT    .078   .000  -.003   .074  -.003  -.001  -.011   .000   .000
jpl0926g.snx: KATZ    .069   .000   .000   .068   .000   .000  -.012   .000   .000
mit0926g.snx: KATZ    .078   .000  -.003   .074  -.003  -.001  -.012   .000   .000
jpl0926g.snx: LPGS    .110   .000   .000   .128   .000   .000   .000   .000   .000
mit0926g.snx: LPGS    .110   .000   .000   .128   .000   .000   .046   .000   .000
jpl0926g.snx: NICO    .110   .000   .000   .128   .000   .000   .000   .000   .000
mit0926g.snx: NICO    .110   .000   .000   .128   .000   .000   .050   .000   .000
jpl0926g.snx: SFER    .110   .000   .000   .128   .000   .000   .000   .000   .000
mit0926g.snx: SFER    .110   .000   .000   .128   .000   .000  1.608   .000   .000
jpl0926g.snx: TELA    .069   .000   .000   .068   .000   .000   .000   .000   .000
mit0926g.snx: TELA    .078   .000  -.003   .074  -.003  -.001   .000   .000   .000
jpl0926g.snx: ZIMM    .069   .000   .000   .068   .000   .000   .000   .000   .000
mit0926g.snx: ZIMM    .078   .000  -.003   .074  -.003  -.001   .000   .000   .000

CONFIDENCE  LEVEL  FOR OUTLIER DETECTION: 99%
OUTLIERS REJECTED (COORD/STATION/GNAACs):
   Lat TAEJ MIT-JPL   Lat TAEJ MIT-NCL   Lon TAEJ MIT-JPL
   Lon BRAZ MIT-JPL   Lon FORT MIT-JPL   Lon GUAM MIT-JPL
   Lon KOUR MIT-JPL   Lon TAEJ MIT-NCL   Lon BRAZ MIT-NCL
   Lon KOUR MIT-NCL   Hgt KWJ1 JPL-NCL   Hgt KWJ1 MIT-JPL
   Hgt THU1 MIT-JPL   Hgt TAEJ MIT-JPL   Hgt MAS1 MIT-NCL
   Hgt CAS1 MIT-NCL   Hgt TAEJ MIT-NCL     

55 GLOBAL STATIONS:
   ALBH ALGO ANKR AREQ ASC1 AUCK BAHR CHAT COCO CRO1
   DGAR DRAO FAIR GOLD HOB2 IISC IRKT KELY KERG KIRU
   KIT3 KOKB KOSG KSTU LHAS MAC1 MALI MATE MCM4 MDO1
   METS MKEA NLIB NTUS ONSA PERT POL2 POTS RCM6 REYK
   SANT SHAO STJO TAHI TAIW TIDB TSKB USUD WES2 WHIT
   WSRT WTZR WUHN YAR1 YELL     

10 FIDUCIAL STATIONS:
   ALGO FAIR GOLD KOKB KOSG SANT TIDB WTZR YAR1 YELL

AVERAGE COORDINATE RMS:

             55    GLOBAL  STATIONS         10   FIDUCIAL   STATIONS
        MIT-JPL   MIT-NCL   JPL-NCL MIT-ITRF94 JPL-ITRF94 NCL-ITRF94
           (mm)      (mm)      (mm)       (mm)       (mm)       (mm)
        -------   -------   ------- ---------- ---------- ----------
Lat        2.0       1.8       0.8        5.4        5.7        5.9 
Lon        2.3       1.7       1.7        8.1        9.4        8.9 
Hgt        4.0       4.6       3.9        8.7       11.0       11.1 
3D         5.0       5.2       4.3       13.1       15.6       15.4

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

        55    GLOBAL  STATIONS         10   FIDUCIAL   STATIONS
   JPL-NCL   MIT-JPL   MIT-NCL MIT-ITRF94 JPL-ITRF94 NCL-ITRF94
   -------   -------   ------- ---------- ---------- ----------
     0.187     1.277     0.543      1.418      1.328      1.465

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      -2.7     3.9     3.2     4.0    -3.3     5.7        -1.4      0.4
MIT      -0.8     2.5     1.2     2.6     1.8     2.5        -1.2      0.4
NCL      -1.0     4.5    10.0     4.6    -5.5     6.4        -1.4      0.4

REMARKS:

THE FOLLOWING FIDUCIAL STATIONS ARE MISSING FROM mit0926g.snx :
   Stations: HART TROM

THE FOLLOWING FIDUCIAL STATIONS ARE MISSING FROM jpl0926g.snx :
   Stations: HART TROM

THE FOLLOWING FIDUCIAL STATIONS ARE MISSING FROM ncl0926g.snx :
   Stations: HART TROM

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

STATION / GNAAC / LONGITUDE DIFFERENCE (mm.):
   MADR JPL -28.5
        MIT -27.3
        NCL -29.9

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

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