Subject: [IGSREPORT-2996] Wk 0864 MIT T2 RNAAC Analyis Report
From: Thomas Herring
Date: Mon, 23 Sep 1996 18:02:24 PDT

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IGS Electronic Report    Mon Sep 23 18:02:24 PDT 1996      Message Number 2996
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Author: Thomas Herring
Subject: Wk 0864 MIT T2 RNAAC Analyis Report

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MIT R/GNAAC  ANALYSIS REPORT GPS-WEEK 0864    Dates: 96jul28  to  96aug03 
********************************************************************************

MIT (Massachusetts Institute of Technology) 
Room 54-618
77 Massachusetts Avenue, 
Cambridge,  MA  02139
e-mail: [email-masked] 
tel:    (617)253-5941 (Tom Herring)
fax:    (617)253-1699

PRODUCTS GENERATED:
The following products are generated and uploaded into CDDIS @ NASA/GSFC
   MIT0864p.SNX   RNAAC combination sinex file from all available analysis centers
                  with the GNAAC sinex files.
   MIT0864p.SUM   Name of this summary file

1.0 Analysis Procedures:

(1) Each centers sinex solutions are de-constrained before
 combination.  When center constraints are available, the
 constraints are loosened to +-1 meters.
(1.b) Due to numerical stability problems we did not include
PGC in this week's analysis.
 
(2) Covariance matrices from each center are re-scaled based
 on the change in chi**2 when the RNAAC's sinex file is
 combined with the loose combination of the GNAAC's 
 sinex files.  To generate reasonable sigmas, the scale factor
 is set at 0.3 times the chi**2/degree of freedom increment.
 
(3) The tight solution is generated with the following constraints on
 the ITRF94 core sites.  In this analysis, the loose g-sinex file
 is combined with the RNAAC sinex files.
           Sig N Sig E Sig U
           (m)    (m)   (m)
     TROM  0.004 0.004 0.004 
     MADR  0.003 0.003 0.003 
     KOSG  0.003 0.003 0.005 
     WETT  0.002 0.002 0.003 
     HART  0.004 0.004 0.004 
     ALGO  0.003 0.003 0.003 
     YELL  0.003 0.003 0.004  
     GOLD  0.004 0.004 0.005 
     FAIR  0.003 0.003 0.003 
     KOKB  0.003 0.003 0.003  
     SANT  0.004 0.004 0.004  
     TIDB  0.004 0.004 0.004 
     YAR1  0.004 0.004 0.005  

Earth rotation parameters are estimated for each center (even when not given
in the original SINEX files.  In this case the partial derivatives are
computed from the station coordinates).

(4) The summary below gives 
    (a) The RMS difference between the GNAAC loose analysis and
the GNAAC+RNAAC loose analysis.  If this RMS is small then the 
RNAAC combination is not effecting the global coordinates solution
significiantly.
    (b) For each RNAAC Center we give:
        (b.1)  the VARIANCE rescaling factors used (determined as 
discussed above) and
        (b.2)  the adjustment to the apriori coordinates
of the sites for each RNAAC which are not included in the GNAAC
analyses.  The apriori coordinates are based on the analysis
of the first five weeks of RNAAC sinex files.  When an RNAAC
has no unique sites, the adjustments are given for all sites
in the center based on the analysis from that center alone.
 
 SUMMARY OF POSITIONS FOR WEEK 0864
 
 IMPACT OF RNAACs on GNAAC Loose solution
 RMS change over  94  stations: 2.17 mm
 
 CENTER RESULTS
 
 For Center ASI VARIANCE FACTOR 1
 Site       dN     +-         dE     +-         dU    +-   Center
           (mm)   (mm)       (mm)   (mm)      (mm)   (mm) 
 THUL       3.0    1.2      -10.6    1.2      -25.9    2.1 Center ASI
 
 For Center EUR VARIANCE FACTOR 1
 Site       dN     +-         dE     +-         dU    +-   Center
           (mm)   (mm)       (mm)   (mm)      (mm)   (mm) 
 CAGL     -14.1    1.2        6.2    1.2       -8.2    1.1 Center EUR
 MEDI     -13.9    1.2        5.6    1.2      -13.3    1.1 Center EUR
 VENE     -14.3    1.2        3.0    1.3      -10.8    1.2 Center EUR
 
 For Center GIA VARIANCE FACTOR 1
 Site       dN     +-         dE     +-         dU    +-   Center
           (mm)   (mm)       (mm)   (mm)      (mm)   (mm) 
 BOGO      -9.4    1.2        6.4    1.2      -21.6    1.3 Center GIA
 CAGL     -14.1    1.2        6.2    1.2       -8.2    1.1 Center GIA
 DELF       0.5    1.1       -9.0    1.2      -20.0    1.2 Center GIA
 DENT      -1.9    1.1      -12.1    1.2      -19.2    1.2 Center GIA
 DOUR      -4.8    1.1       -5.5    1.2      -21.9    1.2 Center GIA
 HFLK     -11.4    1.2        0.8    1.2      -19.4    1.1 Center GIA
 MEDI     -13.9    1.2        5.6    1.2      -13.3    1.1 Center GIA
 PENC     -11.1    1.2        8.2    1.2      -15.8    1.2 Center GIA
 SFER     -14.5    1.4        7.3    1.4      -14.2    6.9 Center GIA
 WARE      -2.9    1.1       -7.9    1.2      -18.6    1.2 Center GIA
 
 For Center GSI VARIANCE FACTOR 26.65
 Site       dN     +-         dE     +-         dU    +-   Center
           (mm)   (mm)       (mm)   (mm)      (mm)   (mm) 
 AIS1     -12.8    3.6       -1.8    6.3       -7.6   11.0 Center GSI
 BAY1     -14.1    5.6      -13.8   10.1        5.1   14.8 Center GSI
 GUS1     -10.4    5.0       -4.3    8.1      -13.5   12.2 Center GSI
 KDK1      -8.8    4.0       -6.9    6.9       -3.3   11.9 Center GSI
 KEN1      -9.5    6.7       -3.5   10.6      -15.8   17.0 Center GSI
 PENT     -11.9    2.1       -3.2    3.9      -19.2    8.8 Center GSI

[Mailed From: Tom Herring <[email-masked]>]