Subject: [IGSREPORT-4125] Wk 0916 G-SINEX Comparisons
From: AC Coordinator / NRCan GSDivision
Date: Fri, 12 Sep 1997 14:02:36 PDT

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IGS Electronic Report    Fri Sep 12 14:02:36 PDT 1997      Message Number 4125
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Author: AC Coordinator / NRCan GSDivision
Subject: Wk 0916 G-SINEX Comparisons

Comparison of GNAAC Combined SINEX Solutions - Week 0916   
(JUL 27, 1997 - AUG 2, 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:
   mit0916g.snx at cddis.gsfc.nasa.gov
   jpl0916g.snx at cddis.gsfc.nasa.gov
   ncl0916g.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))

jpl0916g.snx: BISH    .075   .002  -.001   .069  -.001   .002   .046   .000   .000
mit0916g.snx: BISH    .078   .000  -.003   .074  -.003  -.001   .046   .000   .000
jpl0916g.snx: HARK    .110   .000   .000   .128   .000   .000  9.754   .000   .000
mit0916g.snx: HARK    .078   .000   .000   .096   .000   .000  9.803   .000   .000
ncl0916g.snx: HARK    .110   .000   .000   .128   .000   .000  9.803   .000   .000
jpl0916g.snx: SELE    .110   .000   .000   .128   .000   .000   .000   .000   .000
mit0916g.snx: SELE    .110   .000   .000   .128   .000   .000   .089   .000   .000
jpl0916g.snx: SOFI    .110   .000   .000   .128   .000   .000   .000   .000   .000
mit0916g.snx: SOFI    .110   .000   .000   .128   .000   .000   .219   .000   .000
jpl0916g.snx: TAEJ    .075   .002  -.001   .069  -.001   .002   .660   .000   .000
mit0916g.snx: TAEJ    .075   .002  -.001   .069  -.001   .002   .660   .000   .000
ncl0916g.snx: TAEJ    .078   .000  -.003   .074  -.003  -.001   .660   .000   .000
jpl0916g.snx: ZIMM    .069   .000   .000   .068   .000   .000   .000   .000   .000
mit0916g.snx: ZIMM    .078   .000  -.003   .074  -.003  -.001   .000   .000   .000

ANTENNA PHASE CENTRE CONFLICTS IN FILE mit0916g.snx                             
   AREQ Multiple Sites      
   TAHI Multiple Sites      
   YAR1 Multiple Sites      
   MDVO Multiple Sites      
 
SITES AFFECTED BY ABOVE CONFLICTS, NON-FIDUCIAL SITES SUBSEQUENTLY EXCLUDED:
   Stations: AREQ TAHI YAR1 MDVO 
 
ANTENNA PHASE CENTRE CONFLICTS IN FILE ncl0916g.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      
   XIAN Missing Antenna      
 
SITES AFFECTED BY ABOVE CONFLICTS, NON-FIDUCIAL SITES SUBSEQUENTLY EXCLUDED:
   Stations: ASC1 AUCK CHAT DGAR KIRU KWJ1 MKEA VILL XIAN 

CONFIDENCE  LEVEL  FOR OUTLIER DETECTION: 99%
OUTLIERS REJECTED (COORD/STATION/GNAACs):
   Lat CAS1 JPL-NCL   Lon COCO JPL-NCL   Hgt CRO1 JPL-NCL
   Hgt MCM4 JPL-NCL   Hgt FORT JPL-NCL   Hgt FORT MIT-JPL
   Hgt CRO1 MIT-JPL   Hgt MCM4 MIT-NCL     

48 GLOBAL STATIONS:
   ALBH ALGO ANKR BAHR BOR1 BRAZ BRMU DAV1 DRAO FAIR
   GOLD GUAM HOB2 IISC IRKT KELY KERG KIT3 KOKB KOSG
   KOUR MAC1 MALI MATE MDO1 METS NLIB NYAL ONSA PERT
   POL2 POTS RCM6 REYK SANT SHAO STJO TAIW TIDB TSKB
   USUD WES2 WHIT WTZR WUHN YAR1 YELL ZWEN  

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

AVERAGE COORDINATE RMS:

             48    GLOBAL  STATIONS         10   FIDUCIAL   STATIONS
        MIT-JPL   MIT-NCL   JPL-NCL MIT-ITRF94 JPL-ITRF94 NCL-ITRF94
           (mm)      (mm)      (mm)       (mm)       (mm)       (mm)
        -------   -------   ------- ---------- ---------- ----------
Lat        1.3       2.6       2.0        6.5        6.1        7.1 
Lon        3.1       3.1       1.9        9.5        9.3        8.8 
Hgt        4.3       4.3       2.4       10.8       10.2       10.4 
3D         5.4       5.9       3.7       15.8       15.1       15.4

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

        48    GLOBAL  STATIONS         10   FIDUCIAL   STATIONS
   JPL-NCL   MIT-JPL   MIT-NCL MIT-ITRF94 JPL-ITRF94 NCL-ITRF94
   -------   -------   ------- ---------- ---------- ----------
     0.114     0.893     0.280      1.935      1.423      1.480

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      -2.4     4.6    15.9     4.7   -33.2     7.3        -2.2      0.5
MIT      -4.8     2.9    14.9     3.0   -37.8     3.7        -1.9      0.4
NCL       1.9     4.2    23.0     4.4   -24.2     6.3        -1.9      0.4

REMARKS:

THE FOLLOWING FIDUCIAL STATIONS ARE MISSING FROM mit0916g.snx :
   Stations: HART TROM

THE FOLLOWING FIDUCIAL STATIONS ARE MISSING FROM jpl0916g.snx :
   Stations: TROM

THE FOLLOWING FIDUCIAL STATIONS ARE MISSING FROM ncl0916g.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 -33.0
        MIT -29.2
        NCL -30.9

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

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