Subject: [IGSREPORT-3954] Wk 0910 G-SINEX Comparisons
From: AC Coordinator / NRCan GSDivision
Date: Thu, 17 Jul 1997 7:08:35 PDT

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IGS Electronic Report    Thu Jul 17  7:08:35 PDT 1997      Message Number 3954
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Author: AC Coordinator / NRCan GSDivision
Subject: Wk 0910 G-SINEX Comparisons

Comparison of GNAAC Combined SINEX Solutions - Week 0910   
(JUN 15, 1997 - JUN 21, 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:
   mit0910g.snx at cddis.gsfc.nasa.gov
   jpl0910g.snx at cddis.gsfc.nasa.gov
   ncl0910g.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))

jpl0910g.snx: JOZE    .078   .000  -.003   .074  -.003  -.001   .198   .000   .000
mit0910g.snx: JOZE    .078   .000   .003   .074   .003   .001   .198   .000   .000
jpl0910g.snx: TAEJ    .075   .002  -.001   .069  -.001   .002   .660   .000   .000
mit0910g.snx: TAEJ    .078   .002   .003   .074   .003   .001   .660   .000   .000
ncl0910g.snx: TAEJ    .078   .000  -.003   .074  -.003  -.001   .660   .000   .000
jpl0910g.snx: TAHI    .110   .000   .000   .128   .000   .000  1.055   .000   .000
mit0910g.snx: TAHI    .110   .000   .000   .128   .000   .000  1.054   .000   .000
ncl0910g.snx: TAHI    .110   .000   .000   .128   .000   .000  1.023   .000   .000
jpl0910g.snx: USUD    .110   .000   .000   .128   .000   .000  -.035   .000   .000
mit0910g.snx: USUD    .078   .000   .000   .096   .000   .000  -.035   .000   .000
ncl0910g.snx: USUD    .110   .000   .000   .128   .000   .000  -.035   .000   .000
jpl0910g.snx: YAR1    .078   .000   .000   .096   .000   .000   .073   .000   .000
mit0910g.snx: YAR1    .078   .000   .000   .096   .000   .000   .073   .000   .000
ncl0910g.snx: YAR1    .000   .000   .000   .000   .000   .000   .073   .000   .000
jpl0910g.snx: ZIMM    .069   .000   .000   .068   .000   .000   .000   .000   .000
mit0910g.snx: ZIMM    .078   .000   .003   .074   .003   .001   .000   .000   .000

ANTENNA PHASE CENTRE CONFLICTS IN FILE mit0910g.snx                             
   AREQ Multiple Sites      
   MDVO Multiple Sites
 
SITES AFFECTED BY ABOVE CONFLICTS, NON-FIDUCIAL SITES SUBSEQUENTLY EXCLUDED:
   Stations: AREQ MDVO 
 
ANTENNA PHASE CENTRE CONFLICTS IN FILE ncl0910g.snx                             
   ASC1 Missing Antenna      
   AUCK Missing Antenna      
   CHAT Missing Antenna      
   KWJ1 Missing Antenna      
   MKEA Missing Antenna      
 
SITES AFFECTED BY ABOVE CONFLICTS, NON-FIDUCIAL SITES SUBSEQUENTLY EXCLUDED:
   Stations: ASC1 AUCK CHAT KWJ1 MKEA BAHR YAR1 

CONFIDENCE  LEVEL  FOR OUTLIER DETECTION: 99%
OUTLIERS REJECTED (COORD/STATION/GNAACs):
   Lon CRO1 JPL-NCL   Lon NLIB JPL-NCL   Lon IISC MIT-JPL
   Lon CRO1 MIT-JPL   Hgt MCM4 JPL-NCL   Hgt WUHN JPL-NCL
   Hgt MCM4 MIT-NCL          

44 GLOBAL STATIONS:
   ALBH ALGO ANKR BOR1 BRAZ BRMU COCO DAV1 DRAO FAIR
   FORT GOLD GUAM HOB2 IRKT KELY KERG KIT3 KOKB KOSG
   LHAS MAC1 MALI MATE MDO1 METS NYAL ONSA PERT POL2
   POTS RCM6 REYK SANT SHAO STJO TAIW TIDB TSKB WES2
   WHIT WTZR YAR1 YELL      

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

AVERAGE COORDINATE RMS:

             44    GLOBAL  STATIONS         10   FIDUCIAL   STATIONS
        MIT-JPL   MIT-NCL   JPL-NCL MIT-ITRF94 JPL-ITRF94 NCL-ITRF94
           (mm)      (mm)      (mm)       (mm)       (mm)       (mm)
        -------   -------   ------- ---------- ---------- ----------
Lat        1.8       2.5       1.8        7.2        6.9        6.8 
Lon        1.4       2.4       2.5        8.4        8.9        9.1 
Hgt        2.8       3.2       4.6       11.1       11.0       12.3 
3D         3.6       4.8       5.5       15.7       15.7       16.8

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

        44    GLOBAL  STATIONS         10   FIDUCIAL   STATIONS
   JPL-NCL   MIT-JPL   MIT-NCL MIT-ITRF94 JPL-ITRF94 NCL-ITRF94
   -------   -------   ------- ---------- ---------- ----------
     0.513     0.263     0.596      1.902      1.481      1.831

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       3.6     5.0    35.6     5.1   -63.4    10.9        -1.1      0.4
MIT       2.8     3.4    24.8     3.4   -47.9     5.8        -1.2      0.4
NCL       1.1     4.2    32.4     4.4   -14.7     7.1        -1.4      0.4

REMARKS:

THE FOLLOWING FIDUCIAL STATIONS ARE MISSING FROM mit0910g.snx :
   Stations: HART TROM

THE FOLLOWING FIDUCIAL STATIONS ARE MISSING FROM jpl0910g.snx :
   Stations: HART TROM

THE FOLLOWING FIDUCIAL STATIONS ARE MISSING FROM ncl0910g.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 -24.4
        MIT -26.7
        NCL -29.7

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

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