Subject: [IGSREPORT-4581] Wk 0939 G-SINEX Comparisons
From: AC Coordinator / NRCan GSDivision
Date: Thu, 5 Feb 1998 13:38:16 PST

******************************************************************************
IGS Electronic Report    Thu Feb  5 13:38:16 PST 1998      Message Number 4581
******************************************************************************

Author: AC Coordinator / NRCan GSDivision
Subject: Wk 0939 G-SINEX Comparisons

Comparison of GNAAC Combined SINEX Solutions - Week 0939   
(JAN 4, 1998 - JAN 10, 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:
   mit0939g.snx at cddis.gsfc.nasa.gov
   jpl0939g.snx at cddis.gsfc.nasa.gov
   ncl0939g.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))

jpl0939g.snx: BISH    .075   .002  -.001   .069  -.001   .002   .046   .000   .000
mit0939g.snx: BISH    .078   .000  -.003   .074  -.003  -.001   .046   .000   .000
   - Unresolvable (no log file)

jpl0939g.snx: ELAT    .069   .000   .000   .068   .000   .000  -.011   .000   .000
mit0939g.snx: ELAT    .078   .000  -.003   .074  -.003  -.001  -.011   .000   .000
   - Unresolvable (no log file)

jpl0939g.snx: KATZ    .069   .000   .000   .068   .000   .000  -.012   .000   .000
mit0939g.snx: KATZ    .078   .000  -.003   .074  -.003  -.001  -.012   .000   .000
   - Unresolvable (no log file)

jpl0939g.snx: MALI    .078   .000   .000   .096   .000   .000   .222   .000   .000
mit0939g.snx: MALI    .078   .000   .000   .096   .000   .000   .135   .000   .000
   - Both wrong. Should be L1/L2 offset .110, .128 M., eccentricity 0.135 M.

jpl0939g.snx: TELA    .069   .000   .000   .068   .000   .000   .000   .000   .000
mit0939g.snx: TELA    .078   .000  -.003   .074  -.003  -.001   .000   .000   .000
   - Unresolvable (no log file)

jpl0939g.snx: WUHN    .110   .000   .000   .128   .000   .000  2.320   .000   .000
mit0939g.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.

jpl0939g.snx: YAR1    .078   .000   .000   .096   .000   .000   .073   .000   .000
mit0939g.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.

jpl0939g.snx: GALA    .110   .000   .000   .128   .000   .000   .000   .000   .000
jpl0939g.snx: HARK    .110   .000   .000   .128   .000   .000  9.754   .000   .000
jpl0939g.snx: HOFN    .110   .000   .000   .128   .000   .000   .000   .000   .000
jpl0939g.snx: KOUR    .078   .000   .000   .096   .000   .000   .132   .000   .000
jpl0939g.snx: LPGS    .110   .000   .000   .128   .000   .000   .000   .000   .000
jpl0939g.snx: MOIN    .110   .000   .000   .128   .000   .000   .994   .000   .000
jpl0939g.snx: NICO    .110   .000   .000   .128   .000   .000   .000   .000   .000
jpl0939g.snx: SELE    .110   .000   .000   .128   .000   .000   .000   .000   .000
jpl0939g.snx: ZECK    .110   .000   .000   .128   .000   .000   .000   .000   .000
jpl0939g.snx: ZIMM    .069   .000   .000   .068   .000   .000   .000   .000   .000

FILE ncl0939g.snx MISSING THE SITE/GPS_PHASE_CENTER BLOCK.
DEFAULTING TO KNOWN L1/L2 OFFSETS AND ECCENTRICITIES.

ANTENNA PHASE CENTRE CONFLICTS IN FILE mit0939g.snx                             
   KOUR Multiple Sites       
 
SITES AFFECTED BY ABOVE CONFLICTS, NON-FIDUCIAL SITES SUBSEQUENTLY EXCLUDED:
   Stations: KOUR 
 
CONFIDENCE LEVEL FOR OUTLIER DETECTION (ITRF94): 99%
OUTLIERS REJECTED (COORD/STATION/GNAACs):
   Lat KIT3 MIT-JPL   Lon EISL MIT-NCL   Lon DGAR MIT-NCL
   Hgt IRKT JPL-NCL   Hgt IRKT MIT-JPL   Hgt EISL MIT-NCL

61 GLOBAL STATIONS:
   ALBH ALGO ANKR AREQ ASC1 AUCK BAHR BOR1 BRMU BRUS
   CAS1 CHAT COCO CRO1 DAV1 DRAO FAIR FORT GOLD GUAM
   HOB2 IISC KERG KIRU KOKB KOSG KWJ1 MAC1 MADR MAS1
   MATE MCM4 MDO1 METS MKEA NTUS OHIG ONSA PERT POL2
   POTS RCM6 REYK SANT SHAO STJO TAEJ TAHI THU1 TIDB
   TSKB USUD VILL WES2 WHIT WSRT WTZR XIAN YAR1 YELL
   ZWEN         

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

AVERAGE COORDINATE RMS USING ITRF94:

             61    GLOBAL  STATIONS         11   FIDUCIAL   STATIONS
        MIT-JPL   MIT-NCL   JPL-NCL MIT-ITRF94 JPL-ITRF94 NCL-ITRF94
           (mm)      (mm)      (mm)       (mm)       (mm)       (mm)
        -------   -------   ------- ---------- ---------- ----------
Lat        2.0       1.7       0.9        8.3        8.3        8.6 
Lon        2.1       2.5       1.5       10.1        9.3        9.5 
Hgt        2.8       2.8       2.7       13.2       13.5       13.0 
3D         4.0       4.1       3.2       18.6       18.4       18.2

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

        61    GLOBAL  STATIONS         11   FIDUCIAL   STATIONS
   JPL-NCL   MIT-JPL   MIT-NCL MIT-ITRF94 JPL-ITRF94 NCL-ITRF94
   -------   -------   ------- ---------- ---------- ----------
     0.182     0.752     0.413      3.115      2.192      2.447

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     -10.7     4.1    21.9     4.2    11.5     5.9        -1.7      0.4
MIT      -9.2     2.7     3.1     2.8     8.6     3.3        -1.8      0.3
NCL     -11.4     4.3    16.5     4.4     9.0     6.2        -1.4      0.4

REMARKS:

THE FOLLOWING ITRF94 FIDUCIAL STATIONS ARE MISSING FROM mit0939g.snx :
   Stations: HART TROM

THE FOLLOWING ITRF94 FIDUCIAL STATIONS ARE MISSING FROM jpl0939g.snx :
   Stations: TROM

THE FOLLOWING ITRF94 FIDUCIAL STATIONS ARE MISSING FROM ncl0939g.snx :
   Stations: HART TROM

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

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