[IGSREPORT-3248] Wk 0875 MIT T2 RNAAC Analyis Report

[Thomas]

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IGS Electronic Report    Mon Dec  9 19:34:04 PST 1996      Message Number 3248
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Author: Thomas Herring
Subject: Wk 0875 MIT T2 RNAAC Analyis Report

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MIT R/GNAAC  ANALYSIS REPORT GPS-WEEK 0875    Dates: 96oct13  to  96oct19 
********************************************************************************

MIT (Massachusetts Institute of Technology) 
Room 54-618
77 Massachusetts Avenue, 
Cambridge,  MA  02139
e-mail: tah at mtglas.mit.edu 
tel:    (617)253-5941 (Tom Herring)
fax:    (617)253-1699

PRODUCTS GENERATED:
The following products are generated and uploaded into CDDIS @ NASA/GSFC
   MIT0875p.SNX   RNAAC combination sinex file from all available analysis centers
                  with the GNAAC sinex files.
   MIT0875p.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.
 
(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 0875
 
 IMPACT OF RNAACs on GNAAC Loose solution
 RMS change over  102  stations: .85 mm
 
 CENTER RESULTS
 
 For Center EUR VARIANCE FACTOR 8.25
 Site       dN     +-         dE     +-         dU    +-   Center
           (mm)   (mm)       (mm)   (mm)      (mm)   (mm) 
 BOGO       1.4    1.2       -0.6    1.2       -6.7    2.4 Center EUR
 CAGL       1.0    1.3       -1.6    1.3       -5.4    2.4 Center EUR
 DELF       9.0    1.2      -15.2    1.2       -8.6    2.1 Center EUR
 DENT       8.4    1.2      -17.5    1.2        0.3    2.2 Center EUR
 DOUR       6.2    1.2      -11.7    1.2       -7.2    2.3 Center EUR
 EBRE      -2.5    1.2        3.4    1.3       13.2    3.1 Center EUR
 HFLK       2.7    1.2       -6.1    1.2        0.2    1.9 Center EUR
 MEDI      -1.3    1.2        2.1    1.2       -5.6    2.0 Center EUR
 PENC       1.0    1.2        2.6    1.3       -3.3    2.5 Center EUR
 SFER       6.4    1.3        1.9    1.3        2.8    3.8 Center EUR
 VENE       3.7    1.6        0.5    2.2      -14.8    4.1 Center EUR
 WARE       6.4    1.2      -12.9    1.2       -2.6    2.8 Center EUR
 
 For Center GSI VARIANCE FACTOR 2.38
 Site       dN     +-         dE     +-         dU    +-   Center
           (mm)   (mm)       (mm)   (mm)      (mm)   (mm) 
 CCJM       1.6    2.1       12.4    3.9        8.8   10.0 Center GSI
 KNYA       2.6    1.8        6.4    2.6       -1.8    5.8 Center GSI
 MZSW      11.0    1.9       -2.8    2.1       -7.5    7.5 Center GSI
 OKNW       1.8    2.0        4.3    3.4       -9.1    9.0 Center GSI
 STKW       7.9    1.8        4.5    2.1       -6.1    5.4 Center GSI
 TKBA      11.6    1.9       -0.5    2.1       -2.6    7.1 Center GSI
 TOHK       6.2    2.2        5.2    2.6      -53.0   12.3 Center GSI
 
 For Center PGC VARIANCE FACTOR 1
 Site       dN     +-         dE     +-         dU    +-   Center
           (mm)   (mm)       (mm)   (mm)      (mm)   (mm) 
 HOLB       1.3    1.5        2.4    1.8      -16.9    5.3 Center PGC
 NANO      -2.8    1.4        2.4    1.8        6.7    4.2 Center PGC
 NEAH      -0.2    1.4        2.2    1.8        0.7    4.9 Center PGC
 UCLU       0.7    1.4        8.0    1.8       -1.6    5.0 Center PGC
 WSLR      -6.1    1.4       -5.1    1.8       -2.4    3.9 Center PGC


[Mailed From: Tom Herring <tah at mtglas.mit.edu>]