Subject: [IGSREPORT-4551] Wk 0928 G-SINEX Comparisons
From: AC Coordinator / NRCan GSDivision
Date: Mon, 2 Feb 1998 7:30:25 PST

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IGS Electronic Report    Mon Feb  2  7:30:25 PST 1998      Message Number 4551
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Author: AC Coordinator / NRCan GSDivision
Subject: Wk 0928 G-SINEX Comparisons

Comparison of GNAAC Combined SINEX Solutions - Week 0928   
(OCT 19, 1997 - OCT 25, 1997)

Contacts: J. Kouba ([email-masked])
          D. Hutchison ([email-masked])
          R. Ferland ([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:
   mit0928g.snx at cddis.gsfc.nasa.gov
   jpl0928g.snx at cddis.gsfc.nasa.gov
   ncl0928g.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))

jpl0930g.snx: BISH    .075   .002  -.001   .069  -.001   .002   .046   .000   .000
mit0928g.snx: BISH    .078   .000  -.003   .074  -.003  -.001   .046   .000   .000
   - Unresolvable (no log file)

jpl0928g.snx: ELAT    .069   .000   .000   .068   .000   .000  -.011   .000   .000
mit0928g.snx: ELAT    .078   .000  -.003   .074  -.003  -.001  -.011   .000   .000
   - Unresolvable (no log file)

jpl0928g.snx: KATZ    .069   .000   .000   .068   .000   .000  -.012   .000   .000
mit0928g.snx: KATZ    .078   .000  -.003   .074  -.003  -.001  -.012   .000   .000
   - Unresolvable (no log file)

jpl0928g.snx: TELA    .069   .000   .000   .068   .000   .000   .000   .000   .000
mit0928g.snx: TELA    .078   .000  -.003   .074  -.003  -.001   .000   .000   .000
   - Unresolvable (no log file)

jpl0929g.snx: WUHN    .110   .000   .000   .128   .000   .000  2.320   .000   .000
mit0929g.snx: WUHN    .110   .000   .000   .128   .000   .000  2.285   .000   .000
   - Both wrong. Should be L1/L2 offset .110, .128 M., eccentricity 2.355 M.

jpl0932g.snx: KOUR    .078   .000   .000   .096   .000   .000   .132   .000   .000
mit0932g.snx: KOUR    .078   .000   .000   .096   .000   .000   .045   .000   .000
   - Both wrong. Should be L1/L2 offset .110, .128 M., eccentricity 0.045 M.

jpl0933g.snx: YAR1    .078   .000   .000   .096   .000   .000   .073   .000   .000
mit0933g.snx: YAR1    .078   .000   .000   .096   .000   .000   .073   .000   .000
   - Both wrong. Should be L1/L2 offset .110, .128 M., eccentricity 0.081 M.

ncl0928g.snx: FORT    .110   .000   .000   .128   .000   .000   .000   .000   .000
jpl0928g.snx: GALA    .110   .000   .000   .128   .000   .000   .000   .000   .000
jpl0928g.snx: LPGS    .110   .000   .000   .128   .000   .000   .000   .000   .000
jpl0932g.snx: MALI    .078   .000   .000   .096   .000   .000   .222   .000   .000
jpl0928g.snx: NICO    .110   .000   .000   .128   .000   .000   .000   .000   .000
jpl0928g.snx: SELE    .110   .000   .000   .128   .000   .000   .000   .000   .000
jpl0928g.snx: SFER    .110   .000   .000   .128   .000   .000   .000   .000   .000
jpl0928g.snx: ZECK    .110   .000   .000   .128   .000   .000   .000   .000   .000
jpl0928g.snx: ZIMM    .069   .000   .000   .068   .000   .000   .000   .000   .000

FILE ncl0928g.snx MISSING THE SITE/GPS_PHASE_CENTER BLOCK.
DEFAULTING TO KNOWN L1/L2 OFFSETS AND ECCENTRICITIES.

ANTENNA PHASE CENTRE CONFLICTS IN FILE mit0928g.snx                             
   MALI Multiple Sites       
 
SITES AFFECTED BY ABOVE CONFLICTS, NON-FIDUCIAL SITES SUBSEQUENTLY EXCLUDED:
   Stations: MALI 
 
CONFIDENCE LEVEL FOR OUTLIER DETECTION (ITRF94): 99%
OUTLIERS REJECTED (COORD/STATION/GNAACs):
   Lat NLIB JPL-NCL   Lat KIT3 MIT-JPL   Lat ASC1 MIT-JPL
   Lat HOB2 MIT-JPL   Lat NLIB MIT-JPL   Lat ASC1 MIT-NCL
   Lon KERG MIT-JPL   Lon MAC1 MIT-NCL   Lon KERG MIT-NCL
   Lon HOB2 MIT-NCL   Hgt CAS1 JPL-NCL   Hgt MAS1 MIT-JPL
   Hgt HOB2 MIT-JPL   Hgt CAS1 MIT-NCL   Hgt MAS1 MIT-NCL
   Hgt MCM4 MIT-NCL   Hgt HOB2 MIT-NCL     

55 GLOBAL STATIONS:
   ALBH ALGO ANKR AREQ AUCK BAHR BOR1 BRAZ BRMU CHAT
   COCO CRO1 DGAR DRAO FAIR GOLD GUAM IISC IRKT KELY
   KIRU KOKB KOSG KSTU KWJ1 LHAS MATE MDO1 METS MKEA
   NRC1 NTUS ONSA PERT POL2 POTS RCM6 REYK SANT SHAO
   STJO TAHI TAIW THU1 TIDB TSKB USUD VILL WES2 WHIT
   WSRT WTZR YAR1 YELL ZWEN     

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

AVERAGE COORDINATE RMS USING ITRF94:

             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        1.5       1.0       1.0        7.4        7.3        7.4 
Lon        1.4       1.3       1.1        9.2        9.2        9.1 
Hgt        2.3       3.1       2.7        9.9       10.7       10.0 
3D         3.1       3.5       3.1       15.4       15.8       15.4

VARIANCE FACTORS WITH ITRF94 (CHI-SQUARE / (DEGREES OF FREEDOM)):

        55    GLOBAL  STATIONS         10   FIDUCIAL   STATIONS
   JPL-NCL   MIT-JPL   MIT-NCL MIT-ITRF94 JPL-ITRF94 NCL-ITRF94
   -------   -------   ------- ---------- ---------- ----------
     0.111     0.303     0.193      1.851      1.620      1.591

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     4.3     5.6     4.4   -31.1     6.2        -1.7      0.4
MIT      -2.3     3.0     6.0     3.1   -35.8     3.8        -1.6      0.4
NCL       2.1     4.4     8.0     4.5   -18.2     6.2        -1.9      0.4

REMARKS:

THE FOLLOWING ITRF94 FIDUCIAL STATIONS ARE MISSING FROM mit0928g.snx :
   Stations: HART TROM

THE FOLLOWING ITRF94 FIDUCIAL STATIONS ARE MISSING FROM jpl0928g.snx :
   Stations: HART TROM

THE FOLLOWING ITRF94 FIDUCIAL STATIONS ARE MISSING FROM ncl0928g.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 -23.3
        MIT -21.6
        NCL -24.8

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

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