Subject: [IGSREPORT-4580] Wk 0938 G-SINEX Comparisons
From: AC Coordinator / NRCan GSDivision
Date: Thu, 5 Feb 1998 13:37:15 PST

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IGS Electronic Report    Thu Feb  5 13:37:15 PST 1998      Message Number 4580
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Author: AC Coordinator / NRCan GSDivision
Subject: Wk 0938 G-SINEX Comparisons

Comparison of GNAAC Combined SINEX Solutions - Week 0938   
(DEC 28, 1997 - JAN 3, 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:
   mit0938g.snx at cddis.gsfc.nasa.gov
   jpl0938g.snx at cddis.gsfc.nasa.gov
   ncl0938g.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))

jpl0938g.snx: BISH    .075   .002  -.001   .069  -.001   .002   .046   .000   .000
mit0938g.snx: BISH    .078   .000  -.003   .074  -.003  -.001   .046   .000   .000
   - Unresolvable (no log file)

jpl0938g.snx: ELAT    .069   .000   .000   .068   .000   .000  -.011   .000   .000
mit0938g.snx: ELAT    .078   .000  -.003   .074  -.003  -.001  -.011   .000   .000
   - Unresolvable (no log file)

jpl0938g.snx: KATZ    .069   .000   .000   .068   .000   .000  -.012   .000   .000
mit0938g.snx: KATZ    .078   .000  -.003   .074  -.003  -.001  -.012   .000   .000
   - Unresolvable (no log file)

jpl0938g.snx: KOUR    .078   .000   .000   .096   .000   .000   .132   .000   .000
mit0938g.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.

jpl0938g.snx: TELA    .069   .000   .000   .068   .000   .000   .000   .000   .000
mit0938g.snx: TELA    .078   .000  -.003   .074  -.003  -.001   .000   .000   .000
   - Unresolvable (no log file)

jpl0938g.snx: WUHN    .110   .000   .000   .128   .000   .000  2.320   .000   .000
mit0938g.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.

jpl0938g.snx: YAR1    .078   .000   .000   .096   .000   .000   .073   .000   .000
mit0938g.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.

jpl0938g.snx: GALA    .110   .000   .000   .128   .000   .000   .000   .000   .000
mit0938g.snx: GODE    .110   .000   .000   .128   .000   .000   .000   .000   .000
jpl0938g.snx: HARK    .110   .000   .000   .128   .000   .000  9.754   .000   .000
jpl0938g.snx: HOFN    .110   .000   .000   .128   .000   .000   .000   .000   .000
jpl0938g.snx: LPGS    .110   .000   .000   .128   .000   .000   .000   .000   .000
jpl0938g.snx: MOIN    .110   .000   .000   .128   .000   .000   .994   .000   .000
jpl0938g.snx: NICO    .110   .000   .000   .128   .000   .000   .000   .000   .000
jpl0938g.snx: SELE    .110   .000   .000   .128   .000   .000   .000   .000   .000
jpl0938g.snx: ZIMM    .069   .000   .000   .068   .000   .000   .000   .000   .000

FILE ncl0938g.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 MAS1 MIT-JPL   Lat KERG MIT-JPL   Lat MAS1 MIT-NCL
   Lat KERG MIT-NCL   Lat ASC1 MIT-NCL   Lon BRMU JPL-NCL
   Lon KERG JPL-NCL   Lon FORT JPL-NCL   Lon COCO MIT-JPL
   Hgt MCM4 MIT-JPL   Hgt FORT MIT-JPL   Hgt THU1 MIT-NCL
   Hgt SANT MIT-NCL   Hgt FORT MIT-NCL     

52 GLOBAL STATIONS:
   ALBH ALGO AREQ BAHR CAS1 CHAT CRO1 DAV1 DGAR DRAO
   EISL FAIR GOLD HOB2 IISC IRKT KIRU KIT3 KOKB KOSG
   MAC1 MADR MATE MDO1 METS MKEA NLIB NRC1 NTUS OHIG
   ONSA PERT POL2 POTS RCM6 REYK SHAO STJO TAEJ TAHI
   TIDB TSKB USUD VILL WES2 WHIT WSRT WTZR XIAN YAR1
   YELL ZWEN        

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

AVERAGE COORDINATE RMS USING ITRF94:

             52    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       2.0       1.0        9.0        9.5        9.4 
Lon        2.0       1.7       1.5       11.1       10.6       10.8 
Hgt        2.9       3.2       3.1       15.8       15.2       14.8 
3D         3.9       4.2       3.6       21.3       20.7       20.6

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

        52    GLOBAL  STATIONS         10   FIDUCIAL   STATIONS
   JPL-NCL   MIT-JPL   MIT-NCL MIT-ITRF94 JPL-ITRF94 NCL-ITRF94
   -------   -------   ------- ---------- ---------- ----------
     0.228     0.652     0.386      4.061      3.300      3.133

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     -11.0     4.3    28.4     4.5    20.7     6.4        -1.9      0.4
MIT      -9.0     3.0     8.1     3.2    13.6     3.7        -1.7      0.4
NCL      -9.8     4.8    21.4     5.0    18.5     6.6        -2.0      0.4

REMARKS:

FOR THE FILE mit0938g.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 mit0938g.snx :
   Stations: HART TROM

THE FOLLOWING ITRF94 FIDUCIAL STATIONS ARE MISSING FROM jpl0938g.snx :
   Stations: TROM

THE FOLLOWING ITRF94 FIDUCIAL STATIONS ARE MISSING FROM ncl0938g.snx :
   Stations: HART TROM

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

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