Subject: [IGSREPORT-4568] Wk 0935 G-SINEX Comparisons
From: AC Coordinator / NRCan GSDivision
Date: Tue, 3 Feb 1998 10:21:20 PST

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IGS Electronic Report    Tue Feb  3 10:21:20 PST 1998      Message Number 4568
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Author: AC Coordinator / NRCan GSDivision
Subject: Wk 0935 G-SINEX Comparisons

Subject: Wk 0935 G-SINEX Comparisons

Comparison of GNAAC Combined SINEX Solutions - Week 0935   
(DEC 7, 1997 - DEC 13, 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:
   mit0935g.snx at cddis.gsfc.nasa.gov
   jpl0935g.snx at cddis.gsfc.nasa.gov
   ncl0935g.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))

jpl0935g.snx: BISH    .075   .002  -.001   .069  -.001   .002   .046   .000   .000
mit0935g.snx: BISH    .078   .000  -.003   .074  -.003  -.001   .046   .000   .000
   - Unresolvable (no log file)

jpl0935g.snx: ELAT    .069   .000   .000   .068   .000   .000  -.011   .000   .000
mit0935g.snx: ELAT    .078   .000  -.003   .074  -.003  -.001  -.011   .000   .000
   - Unresolvable (no log file)

jpl0935g.snx: KATZ    .069   .000   .000   .068   .000   .000  -.012   .000   .000
mit0935g.snx: KATZ    .078   .000  -.003   .074  -.003  -.001  -.012   .000   .000
   - Unresolvable (no log file)

jpl0935g.snx: TELA    .069   .000   .000   .068   .000   .000   .000   .000   .000
mit0935g.snx: TELA    .078   .000  -.003   .074  -.003  -.001   .000   .000   .000
   - Unresolvable (no log file)

jpl0935g.snx: WUHN    .110   .000   .000   .128   .000   .000  2.320   .000   .000
mit0935g.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.

jpl0935g.snx: YAR1    .078   .000   .000   .096   .000   .000   .073   .000   .000
mit0935g.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.

mit0935g.snx: GODE    .110   .000   .000   .128   .000   .000   .000   .000   .000
jpl0935g.snx: HARK    .110   .000   .000   .128   .000   .000  9.754   .000   .000
jpl0935g.snx: HOFN    .110   .000   .000   .128   .000   .000   .000   .000   .000
jpl0935g.snx: KOUR    .078   .000   .000   .096   .000   .000   .132   .000   .000
jpl0935g.snx: LPGS    .110   .000   .000   .128   .000   .000   .000   .000   .000
jpl0935g.snx: MOIN    .110   .000   .000   .128   .000   .000   .994   .000   .000
jpl0935g.snx: NICO    .110   .000   .000   .128   .000   .000   .000   .000   .000
jpl0935g.snx: SELE    .110   .000   .000   .128   .000   .000   .000   .000   .000
jpl0935g.snx: ZIMM    .069   .000   .000   .068   .000   .000   .000   .000   .000

FILE ncl0935g.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 OHIG MIT-JPL   Lat KERG MIT-NCL   Lat OHIG MIT-NCL
   Lat HOB2 MIT-NCL   Lat CAS1 MIT-NCL   Lon NTUS MIT-JPL
   Lon AUCK MIT-NCL   Hgt DGAR MIT-NCL   Hgt MCM4 MIT-NCL
   Hgt AREQ MIT-NCL          

52 GLOBAL STATIONS:
   ALBH ALGO ANKR ASC1 BAHR BRAZ BRMU CHAT COCO CRO1
   DRAO EISL FAIR FORT GOLD GUAM IISC IRKT KIRU KIT3
   KOKB KOSG KSTU KWJ1 MAC1 MADR MAS1 MATE MDO1 METS
   MKEA NLIB ONSA PERT POL2 RCM6 REYK SANT SHAO STJO
   TAHI THU1 TIDB TSKB USUD VILL WES2 WHIT WTZR YAR1
   YELL ZWEN        

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

AVERAGE COORDINATE RMS USING ITRF94:

             52    GLOBAL  STATIONS         11   FIDUCIAL   STATIONS
        MIT-JPL   MIT-NCL   JPL-NCL MIT-ITRF94 JPL-ITRF94 NCL-ITRF94
           (mm)      (mm)      (mm)       (mm)       (mm)       (mm)
        -------   -------   ------- ---------- ---------- ----------
Lat        1.2       2.0       1.4        7.8        7.6        7.6 
Lon        1.9       2.6       1.9       10.1        9.4        8.9 
Hgt        2.6       5.4       3.9       11.4       12.1       12.5 
3D         3.5       6.3       4.5       17.1       17.1       17.1

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

        52    GLOBAL  STATIONS         11   FIDUCIAL   STATIONS
   JPL-NCL   MIT-JPL   MIT-NCL MIT-ITRF94 JPL-ITRF94 NCL-ITRF94
   -------   -------   ------- ---------- ---------- ----------
     0.251     0.790     0.901      2.401      1.792      1.816

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      -6.0     4.1     2.3     4.4    -5.2     6.2        -1.4      0.4
MIT      -2.1     2.7    -3.7     2.8   -13.9     3.3        -1.3      0.3
NCL      -9.1     4.4    10.4     4.5     8.3     6.4        -1.6      0.4

REMARKS:

THE FOLLOWING ITRF94 FIDUCIAL STATIONS ARE MISSING FROM mit0935g.snx :
   Stations: HART TROM

THE FOLLOWING ITRF94 FIDUCIAL STATIONS ARE MISSING FROM jpl0935g.snx :
   Stations: TROM

THE FOLLOWING ITRF94 FIDUCIAL STATIONS ARE MISSING FROM ncl0935g.snx :
   Stations: HART TROM

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

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