[IGSREPORT-4054] Wk 0915 G-SINEX Comparisons

AC AC
Wed Aug 20 07:48:53 PDT 1997


******************************************************************************
IGS Electronic Report    Wed Aug 20  7:48:53 PDT 1997      Message Number 4054
******************************************************************************

Author: AC Coordinator / NRCan GSDivision
Subject: Wk 0915 G-SINEX Comparisons

Comparison of GNAAC Combined SINEX Solutions - Week 0915   
(JUL 20, 1997 - JUL 26, 1997)

Contacts: J. Kouba (kouba at geod.emr.ca)
          D. Hutchison(hutch at geod.emr.ca)

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:
   mit0915g.snx at cddis.gsfc.nasa.gov
   jpl0915g.snx at cddis.gsfc.nasa.gov
   ncl0915g.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))

jpl0915g.snx: BISH    .075   .002  -.001   .069  -.001   .002   .046   .000   .000
mit0915g.snx: BISH    .078   .000  -.003   .074  -.003  -.001   .046   .000   .000
jpl0915g.snx: HARK    .110   .000   .000   .128   .000   .000  9.754   .000   .000
mit0915g.snx: HARK    .110   .000   .000   .128   .000   .000  9.802   .000   .000
ncl0915g.snx: HARK    .110   .000   .000   .128   .000   .000  9.803   .000   .000
jpl0915g.snx: SELE    .110   .000   .000   .128   .000   .000   .000   .000   .000
mit0915g.snx: SELE    .110   .000   .000   .128   .000   .000   .089   .000   .000
jpl0915g.snx: SOFI    .110   .000   .000   .128   .000   .000   .000   .000   .000
mit0915g.snx: SOFI    .110   .000   .000   .128   .000   .000   .219   .000   .000
jpl0915g.snx: TAEJ    .075   .002  -.001   .069  -.001   .002   .660   .000   .000
mit0915g.snx: TAEJ    .078   .002  -.003   .074  -.003  -.001   .660   .000   .000
ncl0915g.snx: TAEJ    .078   .000  -.003   .074  -.003  -.001   .660   .000   .000
jpl0915g.snx: USUD    .110   .000   .000   .128   .000   .000  -.035   .000   .000
mit0915g.snx: USUD    .078   .000   .000   .096   .000   .000  -.035   .000   .000
ncl0915g.snx: USUD    .110   .000   .000   .128   .000   .000  -.035   .000   .000
jpl0915g.snx: ZIMM    .069   .000   .000   .068   .000   .000   .000   .000   .000
mit0915g.snx: ZIMM    .078   .000  -.003   .074  -.003  -.001   .000   .000   .000

 
ANTENNA PHASE CENTRE CONFLICTS IN FILE ncl0915g.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):
   Hgt CRO1 JPL-NCL   Hgt MCM4 JPL-NCL   Hgt MCM4 MIT-JPL
   Hgt KOUR MIT-JPL   Hgt FORT MIT-JPL   Hgt CRO1 MIT-NCL
   Hgt FORT MIT-NCL          

48 GLOBAL STATIONS:
   ALBH ALGO ANKR AREQ BAHR BOR1 BRAZ BRMU BRUS CAS1
   CHUR DAV1 DRAO FAIR GOLD GUAM HOB2 IISC IRKT KERG
   KIT3 KOKB KOSG MAC1 MALI MATE MDO1 METS NYAL ONSA
   PERT POL2 POTS REYK SANT SHAO STJO TAHI TAIW TIDB
   TSKB 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        1.8       2.1       3.1        6.1        6.1        6.3 
Lon        4.9       2.2       6.1        8.3        8.5        8.5 
Hgt        5.4       5.0       3.3       10.1        9.9       10.2 
3D         7.5       5.8       7.6       14.4       14.4       14.7


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
   -------   -------   ------- ---------- ---------- ----------
     0.178     1.486     0.305      1.716      1.242      1.351

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      -9.6     4.7    26.5     4.8   -36.8     7.4        -1.2      0.4
MIT      -8.8     3.0    27.1     3.0   -38.9     3.8        -1.1      0.4
NCL      -2.7     4.4    24.9     4.6   -23.1     6.3        -1.1      0.4

REMARKS:

THE FOLLOWING FIDUCIAL STATIONS ARE MISSING FROM mit0915g.snx :
   Stations: HART TROM

THE FOLLOWING FIDUCIAL STATIONS ARE MISSING FROM jpl0915g.snx :
   Stations: HART TROM

THE FOLLOWING FIDUCIAL STATIONS ARE MISSING FROM ncl0915g.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 -36.8
        MIT -28.4
        NCL -30.7

THE FOLLOWING LARGE HEIGHT DIFFERENCES > 1 CM. MAY CONTRIBUTE TO THE HIGH
VARIANCE FACTOR (1.486) BETWEEN MIT AND JPL.
(GNAAC PAIR / STATION / HEIGHT DIFFERENCE (mm.))

MIT-JPL BAHR  20.93
MIT-JPL TSKB -11.18
MIT-JPL WUHN  13.71

-- 
David Hutchison
Geodetic Survey of Canada
Ottawa, Ontario, Canada
Internet: hutch at geod.emr.ca


[Mailed From: David Hutchison <hutch at geod.emr.ca>]



More information about the IGSREPORT mailing list