Subject: [IGSREPORT-4307] Subject
From: AC Coordinator / NRCan GSDivision
Date: Thu, 6 Nov 1997 7:00:08 PST

IGS Electronic Report    Thu Nov  6  7:00:08 PST 1997      Message Number 4307
******************************************************************************

Author: AC Coordinator / NRCan GSDivision
Subject: Subject: Wk 0927 G-SINEX Comparisons

Comparison of GNAAC Combined SINEX Solutions - Week 0927   
(OCT 12, 1997 - OCT 18, 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:
   mit0927g.snx at cddis.gsfc.nasa.gov
   jpl0927g.snx at cddis.gsfc.nasa.gov
   ncl0927g.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))

jpl0927g.snx: BISH    .075   .002  -.001   .069  -.001   .002   .046   .000   .000
mit0927g.snx: BISH    .078   .000  -.003   .074  -.003  -.001   .046   .000   .000
jpl0927g.snx: ELAT    .069   .000   .000   .068   .000   .000  -.011   .000   .000
mit0927g.snx: ELAT    .078   .000  -.003   .074  -.003  -.001  -.011   .000   .000
jpl0927g.snx: GALA    .110   .000   .000   .128   .000   .000   .000   .000   .000
mit0927g.snx: GALA    .110   .000   .000   .128   .000   .000   .082   .000   .000
jpl0927g.snx: KATZ    .069   .000   .000   .068   .000   .000  -.012   .000   .000
mit0927g.snx: KATZ    .078   .000  -.003   .074  -.003  -.001  -.012   .000   .000
jpl0927g.snx: KOUR    .078   .000   .000   .096   .000   .000   .132   .000   .000
mit0927g.snx: KOUR    .110   .000   .000   .128   .000   .000   .045   .000   .000
jpl0927g.snx: LPGS    .110   .000   .000   .128   .000   .000   .000   .000   .000
mit0927g.snx: LPGS    .110   .000   .000   .128   .000   .000   .046   .000   .000
jpl0927g.snx: NICO    .110   .000   .000   .128   .000   .000   .000   .000   .000
mit0927g.snx: NICO    .110   .000   .000   .128   .000   .000   .050   .000   .000
jpl0927g.snx: SELE    .110   .000   .000   .128   .000   .000   .000   .000   .000
mit0927g.snx: SELE    .110   .000   .000   .128   .000   .000   .091   .000   .000
jpl0927g.snx: SFER    .110   .000   .000   .128   .000   .000   .000   .000   .000
mit0927g.snx: SFER    .110   .000   .000   .128   .000   .000  1.608   .000   .000
jpl0927g.snx: TELA    .069   .000   .000   .068   .000   .000   .000   .000   .000
mit0927g.snx: TELA    .078   .000  -.003   .074  -.003  -.001   .000   .000   .000
jpl0927g.snx: ZECK    .110   .000   .000   .128   .000   .000   .000   .000   .000
mit0927g.snx: ZECK    .110   .000   .000   .128   .000   .000   .045   .000   .000
jpl0927g.snx: ZIMM    .069   .000   .000   .068   .000   .000   .000   .000   .000
mit0927g.snx: ZIMM    .078   .000  -.003   .074  -.003  -.001   .000   .000   .000

CONFIDENCE  LEVEL  FOR OUTLIER DETECTION: 99%
OUTLIERS REJECTED (COORD/STATION/GNAACs):
   Lat CAS1 JPL-NCL   Lat BRAZ JPL-NCL   Lat AREQ JPL-NCL
   Lat SANT JPL-NCL   Lat KERG MIT-NCL   Lon MALI JPL-NCL
   Lon TAEJ MIT-JPL   Lon MALI MIT-JPL   Lon TAEJ MIT-NCL
   Lon FORT MIT-NCL   Lon AUCK MIT-NCL   Hgt MCM4 MIT-JPL
   Hgt CAS1 MIT-JPL   Hgt MAS1 MIT-JPL   Hgt TAEJ MIT-JPL
   Hgt CAS1 MIT-NCL   Hgt MCM4 MIT-NCL   Hgt MAS1 MIT-NCL
   Hgt TAEJ MIT-NCL          

56 GLOBAL STATIONS:
   ALBH ALGO ANKR ASC1 BAHR BOR1 BRUS CHAT COCO CRO1
   DGAR DRAO FAIR GOLD GUAM HOB2 IISC IRKT KELY KIRU
   KIT3 KOKB KOSG KSTU KWJ1 LHAS MAC1 MATE MDO1 MDVO
   METS MKEA NLIB NTUS ONSA PERT POL2 POTS RCM6 REYK
   SHAO STJO TAHI THU1 TIDB TSKB USUD VILL WES2 WHIT
   WSRT WTZR WUHN YAR1 YELL ZWEN    

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

AVERAGE COORDINATE RMS:

             56    GLOBAL  STATIONS          9   FIDUCIAL   STATIONS
        MIT-JPL   MIT-NCL   JPL-NCL MIT-ITRF94 JPL-ITRF94 NCL-ITRF94
           (mm)      (mm)      (mm)       (mm)       (mm)       (mm)
        -------   -------   ------- ---------- ---------- ----------
Lat        1.3       1.0       1.4        6.8        6.3        6.7 
Lon        2.0       2.2       1.9       10.3        8.6        8.9 
Hgt        3.3       3.7       2.9       12.0       11.7       10.3 
3D         4.1       4.4       3.7       17.2       15.8       15.2

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

        56    GLOBAL  STATIONS          9   FIDUCIAL   STATIONS
   JPL-NCL   MIT-JPL   MIT-NCL MIT-ITRF94 JPL-ITRF94 NCL-ITRF94
   -------   -------   ------- ---------- ---------- ----------
     0.220     0.911     0.590      2.357      1.575      1.534

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      -7.2     4.2    14.6     4.4   -11.9     6.3        -1.7      0.4
MIT      -7.0     3.0    11.8     3.2   -19.0     3.4        -1.6      0.4
NCL      -5.8     4.3    16.7     4.5   -12.4     6.4        -1.9      0.4

REMARKS:

FOR THE FILE mit0922g.snx, THE A PRIORI COVARIANCE MATRIX WAS SCALED UPWARD
(ALL ELEMENTS) BY A FACTOR OF 0.05% PRIOR TO DECONSTRAINING.

THE FOLLOWING FIDUCIAL STATIONS ARE MISSING FROM mit0927g.snx :
   Stations: HART TROM

THE FOLLOWING FIDUCIAL STATIONS ARE MISSING FROM jpl0927g.snx :
   Stations: HART TROM

THE FOLLOWING FIDUCIAL STATIONS ARE MISSING FROM ncl0927g.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 -23.8
        MIT -24.5
        NCL -27.7

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

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