Subject: [IGSREPORT-4634] Wk 0941 G-SINEX Comparisons
From: AC Coordinator / NRCan GSDivision
Date: Tue, 24 Feb 1998 7:19:49 PST

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IGS Electronic Report    Tue Feb 24  7:19:49 PST 1998      Message Number 4634
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Author: AC Coordinator / NRCan GSDivision
Subject: Wk 0941 G-SINEX Comparisons

Comparison of GNAAC Combined SINEX Solutions - Week 0941   
(JAN 18, 1998 - JAN 24, 1998)

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:
   mit0941g.snx at cddis.gsfc.nasa.gov
   jpl0941g.snx at cddis.gsfc.nasa.gov
   ncl0941g.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))

jpl0941g.snx: BISH    .075   .002  -.001   .069  -.001   .002   .046   .000   .000
mit0941g.snx: BISH    .078   .000  -.003   .074  -.003  -.001   .046   .000   .000
   - Unresolvable (no log file)

jpl0941g.snx: ELAT    .069   .000   .000   .068   .000   .000  -.011   .000   .000
mit0941g.snx: ELAT    .078   .000  -.003   .074  -.003  -.001  -.011   .000   .000
   - Unresolvable (no log file)

jpl0941g.snx: KATZ    .069   .000   .000   .068   .000   .000  -.012   .000   .000
mit0941g.snx: KATZ    .078   .000  -.003   .074  -.003  -.001  -.012   .000   .000
   - Unresolvable (no log file)

jpl0941g.snx: KOUR    .078   .000   .000   .096   .000   .000   .132   .000   .000
mit0941g.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.

jpl0941g.snx: TELA    .069   .000   .000   .068   .000   .000   .000   .000   .000
mit0941g.snx: TELA    .078   .000  -.003   .074  -.003  -.001   .000   .000   .000
   - Unresolvable (no log file)

jpl0941g.snx: WUHN    .110   .000   .000   .128   .000   .000  2.320   .000   .000
mit0941g.snx: WUHN    .110   .000   .000   .128   .000   .000  2.320   .000   .000
   - Both wrong. Should be L1/L2 offset .110, .128 M., eccentricity 2.355 M.

jpl0941g.snx: YAR1    .078   .000   .000   .096   .000   .000   .073   .000   .000
mit0941g.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.

jpl0941g.snx: GALA    .110   .000   .000   .128   .000   .000   .000   .000   .000
jpl0941g.snx: HARK    .110   .000   .000   .128   .000   .000  9.754   .000   .000
jpl0941g.snx: HOFN    .110   .000   .000   .128   .000   .000   .000   .000   .000
jpl0941g.snx: LPGS    .110   .000   .000   .128   .000   .000   .000   .000   .000
jpl0941g.snx: MALI    .078   .000   .000   .096   .000   .000   .222   .000   .000
ncl0941g.snx: MDVO    Antenna Missing                           .146   .000   .000
jpl0941g.snx: MOIN    .110   .000   .000   .128   .000   .000   .994   .000   .000
jpl0941g.snx: NICO    .110   .000   .000   .128   .000   .000   .000   .000   .000
jpl0941g.snx: SELE    .110   .000   .000   .128   .000   .000   .000   .000   .000
jpl0941g.snx: UPAD    .078   .000  -.003   .074  -.003  -.001  1.962   .000   .000
jpl0941g.snx: ZECK    .110   .000   .000   .128   .000   .000   .000   .000   .000
jpl0941g.snx: ZIMM    .069   .000   .000   .068   .000   .000   .000   .000   .000

FILE ncl0941g.snx MISSING THE SITE/GPS_PHASE_CENTER BLOCK.
DEFAULTING TO KNOWN L1/L2 OFFSETS AND ECCENTRICITIES.

CONFIDENCE LEVEL FOR OUTLIER DETECTION (ITRF94): 99%
OUTLIERS REJECTED (COORD/STATION/GNAACs):
   Lat KERG MIT-JPL   Lat DAV1 MIT-JPL   Lat KERG MIT-NCL
   Lat DAV1 MIT-NCL   Lon GUAM MIT-JPL   Lon MCM4 MIT-JPL
   Lon KERG MIT-JPL   Lon COCO MIT-JPL   Hgt EISL JPL-NCL
   Hgt DGAR MIT-JPL   Hgt GUAM MIT-JPL   Hgt FORT MIT-JPL
   Hgt EISL MIT-JPL   Hgt DGAR MIT-NCL     

59 GLOBAL STATIONS:
   ALBH ALGO ANKR AREQ ASC1 AUCK BAHR BOR1 BRAZ BRMU
   BRUS CAS1 CHAT CRO1 DRAO FAIR GOLD GRAZ HOB2 IISC
   IRKT KELY KIRU KIT3 KOKB KOSG KWJ1 MAC1 MADR MAS1
   MATE MDO1 METS MKEA NLIB NRC1 NTUS OHIG ONSA PERT
   POTS RCM6 REYK SANT STJO TAEJ TAHI THU1 TIDB TSKB
   USUD VILL WES2 WHIT WSRT WTZR YAR1 YELL ZWEN 

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

AVERAGE COORDINATE RMS USING ITRF94:

             59    GLOBAL  STATIONS         11   FIDUCIAL   STATIONS
        MIT-JPL   MIT-NCL   JPL-NCL MIT-ITRF94 JPL-ITRF94 NCL-ITRF94
           (mm)      (mm)      (mm)       (mm)       (mm)       (mm)
        -------   -------   ------- ---------- ---------- ----------
Lat        1.5       2.0       1.1        8.3        8.0        8.4 
Lon        2.8       2.0       1.6        8.7        8.5        8.6 
Hgt        2.4       3.0       2.0        7.5        6.9        7.9 
3D         4.0       4.1       2.8       14.2       13.6       14.4

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

        59    GLOBAL  STATIONS         11   FIDUCIAL   STATIONS
   JPL-NCL   MIT-JPL   MIT-NCL MIT-ITRF94 JPL-ITRF94 NCL-ITRF94
   -------   -------   ------- ---------- ---------- ----------
     0.104     0.866     0.460      1.684      1.301      1.337

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     -10.5     4.6    28.3     4.6    16.7     6.9        -1.4      0.4
MIT     -10.6     2.6     3.2     2.7    10.9     3.0        -1.5      0.3
NCL      -8.5     4.8    24.8     4.9    15.5     7.1        -1.3      0.4

REMARKS:

FOR THE FILE mit0941g.snx, THE A PRIORI COVARIANCE MATRIX WAS SCALED UPWARD
(ALL ELEMENTS) BY A FACTOR OF 0.05% PRIOR TO DECONSTRAINING.

THE FOLLOWING ITRF94 FIDUCIAL STATIONS ARE MISSING FROM mit0941g.snx :
   Stations: HART TROM

THE FOLLOWING ITRF94 FIDUCIAL STATIONS ARE MISSING FROM jpl0941g.snx :
   Stations: TROM

THE FOLLOWING ITRF94 FIDUCIAL STATIONS ARE MISSING FROM ncl0941g.snx :
   Stations: HART TROM

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

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