Subject: [IGSREPORT-3945] Wk 0908 G-SINEX Comparisons
From: AC Coordinator / NRCan GSDivision
Date: Wed, 16 Jul 1997 9:44:18 PDT

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IGS Electronic Report    Wed Jul 16  9:44:18 PDT 1997      Message Number 3945
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Author: AC Coordinator / NRCan GSDivision
Subject: Wk 0908 G-SINEX Comparisons

Comparison of GNAAC Combined SINEX Solutions - Week 0908   
(JUN 1, 1997 - JUN 7, 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:
   mit0908g.snx at cddis.gsfc.nasa.gov
   jpl0908g.snx at cddis.gsfc.nasa.gov
   ncl0908g.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))

jpl0908g.snx: JOZE    .078   .000  -.003   .074  -.003  -.001   .198   .000   .000
mit0908g.snx: JOZE    .069   .000  -.003   .068  -.003  -.001   .198   .000   .000
jpl0908g.snx: TAEJ    .075   .002  -.001   .069  -.001   .002   .660   .000   .000
mit0908g.snx: TAEJ    .069   .002  -.001   .068  -.001   .002   .660   .000   .000
jpl0908g.snx: TAHI    .110   .000   .000   .128   .000   .000  1.055   .000   .000
mit0908g.snx: TAHI    .110   .000   .000   .128   .000   .000  1.055   .000   .000
ncl0908g.snx: TAHI    .110   .000   .000   .128   .000   .000  1.023   .000   .000
jpl0908g.snx: YAR1    .078   .000   .000   .096   .000   .000   .073   .000   .000
mit0908g.snx: YAR1    .078   .000   .000   .096   .000   .000   .073   .000   .000
ncl0908g.snx: YAR1    .000   .000   .000   .000   .000   .000   .073   .000   .000
jpl0908g.snx: ZIMM    .069   .000   .000   .068   .000   .000   .000   .000   .000
mit0908g.snx: ZIMM    .069   .000  -.003   .068  -.003  -.001   .000   .000   .000

ANTENNA PHASE CENTRE CONFLICTS IN FILE mit0908g.snx                             
   MDVO Multiple Sites
 
SITES AFFECTED BY ABOVE CONFLICTS, NON-FIDUCIAL SITES SUBSEQUENTLY EXCLUDED:
   Stations: MDVO 
 
ANTENNA PHASE CENTRE CONFLICTS IN FILE ncl0908g.snx                             
   ASC1 Missing Antenna      
   AUCK Missing Antenna      
   CHAT Missing Antenna      
   DGAR Missing Antenna      
   KWJ1 Missing Antenna      
   MKEA Missing Antenna      
 
SITES AFFECTED BY ABOVE CONFLICTS, NON-FIDUCIAL SITES SUBSEQUENTLY EXCLUDED:
   Stations: ASC1 AUCK CHAT DGAR KWJ1 MKEA BAHR YAR1 

CONFIDENCE  LEVEL  FOR OUTLIER DETECTION: 99%
OUTLIERS REJECTED (COORD/STATION/GNAACs):
   Lat KOKB JPL-NCL   Lat CRO1 MIT-JPL   Lat FORT MIT-JPL
   Lon TIDB JPL-NCL   Lon HOB2 JPL-NCL   Lon MAC1 JPL-NCL
   Lon MALI JPL-NCL   Lon MALI MIT-JPL   Lon HOB2 MIT-JPL
   Lon TIDB MIT-JPL   Hgt CRO1 JPL-NCL   Hgt WUHN MIT-JPL
   Hgt CRO1 MIT-JPL   Hgt WUHN MIT-NCL     

43 GLOBAL STATIONS:
   ALGO ANKR BOR1 BRAZ BRMU CAS1 COCO DAV1 DRAO FAIR
   GOLD GUAM IISC IRKT KELY KERG KIT3 KOSG LHAS MATE
   MCM4 MDO1 METS NLIB NYAL OHIG ONSA PERT POTS RCM6
   REYK SANT SHAO STJO TAIW TSKB USUD WES2 WHIT WTZR
   YAR1 YELL ZWEN       

8 FIDUCIAL STATIONS:
   ALGO FAIR GOLD KOSG SANT WTZR YAR1 YELL  

AVERAGE COORDINATE RMS:

             43    GLOBAL  STATIONS          8   FIDUCIAL   STATIONS
        MIT-JPL   MIT-NCL   JPL-NCL MIT-ITRF94 JPL-ITRF94 NCL-ITRF94
           (mm)      (mm)      (mm)       (mm)       (mm)       (mm)
        -------   -------   ------- ---------- ---------- ----------
Lat        1.2       1.2       1.1        6.2        6.6        6.4 
Lon        2.2       1.2       2.4        8.6        7.0        8.6 
Hgt        4.8       3.3       4.3       11.8        7.5       12.0 
3D         5.5       3.7       5.0       15.8       12.2       16.1

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

        43    GLOBAL  STATIONS          8   FIDUCIAL   STATIONS
   JPL-NCL   MIT-JPL   MIT-NCL MIT-ITRF94 JPL-ITRF94 NCL-ITRF94
   -------   -------   ------- ---------- ---------- ----------
     0.376     0.909     0.205      2.078      0.978      1.680

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       1.8     3.6     2.7     3.4     4.4     3.4        -1.3      0.5
MIT      -0.9     3.6    16.6     3.4   -28.7     4.5        -2.0      0.4
NCL       2.9     5.0    20.8     5.0   -15.7     7.1        -1.9      0.5

REMARKS:

THE FOLLOWING FIDUCIAL STATIONS ARE MISSING FROM mit0908g.snx :
   Stations: HART 

THE FOLLOWING FIDUCIAL STATIONS ARE MISSING FROM jpl0908g.snx :
   Stations: TROM

THE FOLLOWING FIDUCIAL STATIONS ARE MISSING FROM ncl0908g.snx :
   Stations: TROM

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

STATION / GNAAC / LONGITUDE DIFFERENCE (mm.):
   MADR JPL -23.9
        MIT -23.7
        NCL -22.1

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

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