Subject: [IGSREPORT-4053] Wk 0914 G-SINEX Comparisons
From: AC Coordinator / NRCan GSDivision
Date: Wed, 20 Aug 1997 7:47:04 PDT

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IGS Electronic Report    Wed Aug 20  7:47:04 PDT 1997      Message Number 4053
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Author: AC Coordinator / NRCan GSDivision
Subject: Wk 0914 G-SINEX Comparisons

Subject: Wk 0914 G-SINEX Comparisons

Comparison of GNAAC Combined SINEX Solutions - Week 0914   
(JUL 13, 1997 - JUL 19, 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:
   mit0914g.snx at cddis.gsfc.nasa.gov
   jpl0914g.snx at cddis.gsfc.nasa.gov
   ncl0914g.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))

jpl0914g.snx: BISH    .075   .002  -.001   .069  -.001   .002   .046   .000   .000
mit0914g.snx: BISH    .078   .000  -.003   .074  -.003  -.001   .046   .000   .000
jpl0914g.snx: HARK    .110   .000   .000   .128   .000   .000  9.754   .000   .000
mit0914g.snx: HARK    .110   .000   .000   .128   .000   .000  9.803   .000   .000
ncl0914g.snx: HARK    .110   .000   .000   .128   .000   .000  9.803   .000   .000
jpl0914g.snx: LHAS    .110   .000   .000   .128   .000   .000   .058   .000   .000
mit0914g.snx: LHAS    .000   .000   .000   .000   .000   .000   .000   .000   .000
jpl0914g.snx: TAEJ    .075   .002  -.001   .069  -.001   .002   .660   .000   .000
mit0914g.snx: TAEJ    .075   .002  -.001   .069  -.001   .002   .660   .000   .000
ncl0914g.snx: TAEJ    .078   .000  -.003   .074  -.003  -.001   .660   .000   .000
jpl0914g.snx: USUD    .110   .000   .000   .128   .000   .000  -.035   .000   .000
mit0914g.snx: USUD    .078   .000   .000   .096   .000   .000  -.035   .000   .000
ncl0914g.snx: USUD    .110   .000   .000   .128   .000   .000  -.035   .000   .000
jpl0914g.snx: ZIMM    .069   .000   .000   .068   .000   .000   .000   .000   .000
mit0914g.snx: ZIMM    .078   .000  -.003   .074  -.003  -.001   .000   .000   .000

ANTENNA PHASE CENTRE CONFLICTS IN FILE mit0914g.snx                             
   AREQ Multiple Sites      
   MDVO Multiple Sites      
 
SITES AFFECTED BY ABOVE CONFLICTS, NON-FIDUCIAL SITES SUBSEQUENTLY EXCLUDED:
   Stations: AREQ MDVO 
 
ANTENNA PHASE CENTRE CONFLICTS IN FILE ncl0914g.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):
   Lat COCO JPL-NCL   Lat MADR JPL-NCL   Lon TAHI JPL-NCL
   Lon KOUR JPL-NCL   Lon KOUR MIT-JPL   Lon MADR MIT-JPL
   Lon MADR MIT-NCL   Hgt KOUR JPL-NCL   Hgt MCM4 MIT-JPL
   Hgt FORT MIT-JPL   Hgt KOUR MIT-JPL   Hgt MCM4 MIT-NCL
   Hgt CRO1 MIT-NCL   Hgt FORT MIT-NCL     

43 GLOBAL STATIONS:
   ALBH ALGO BAHR BOR1 BRAZ BRMU CAS1 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 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:

             43    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       1.5       2.4        6.9        6.9        8.9 
Lon        2.4       1.5       1.9        9.4        9.0       11.2 
Hgt        5.9       4.5       3.7       10.9       10.4       11.3 
3D         6.5       5.0       4.8       16.0       15.4       18.3

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

        43    GLOBAL  STATIONS         10   FIDUCIAL   STATIONS
   JPL-NCL   MIT-JPL   MIT-NCL MIT-ITRF94 JPL-ITRF94 NCL-ITRF94
   -------   -------   ------- ---------- ---------- ----------
     0.182     1.495     0.182      1.952      1.409      1.432

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       1.9     4.8    25.7     5.0   -29.2     8.2        -1.7      0.4
MIT      -1.4     3.0    21.0     3.0   -30.9     3.9        -1.7      0.4
NCL       2.1     3.2     6.7     3.4     3.6     3.1        -1.7      0.5

REMARKS:

THE FOLLOWING FIDUCIAL STATIONS ARE MISSING FROM mit0914g.snx :
   Stations: HART TROM

THE FOLLOWING FIDUCIAL STATIONS ARE MISSING FROM jpl0914g.snx :
   Stations: HART TROM

THE FOLLOWING FIDUCIAL STATIONS ARE MISSING FROM ncl0914g.snx :
   Stations: HART TROM

THE FOLLOWING LARGE HEIGHT DIFFERENCES > 1 CM. MAY CONTRIBUTE TO THE HIGH
VARIANCE FACTOR (1.495) BETWEEN MIT AND JPL.
(GNAAC PAIR / STATION / HEIGHT DIFFERENCE (mm.))

MIT-JPL BAHR  22.42
MIT-JPL IRKT  15.23
MIT-JPL WUHN  18.37

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

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