From tah at mtglas2.mit.edu Wed May 14 06:51:50 2008 From: tah at mtglas2.mit.edu (Tom Herring) Date: Wed, 14 May 2008 09:51:50 -0400 (EDT) Subject: [IGSREPORT-16227] Wk 1472 MIT T2 RNAAC Analyis Report Message-ID: <200805141351.JAA29858@mtglas2.mit.edu> ****************************************************************************** IGS Electronic Report 14 May 06:36:50 PDT 2008 Message Number 16227 ****************************************************************************** Author: Thomas Herring ******************************************************************************** MIT R/GNAAC ANALYSIS REPORT GPS-WEEK 1472 Dates: 08mar23 to 08mar29 ******************************************************************************** MIT (Massachusetts Institute of Technology) Room 54-820A 77 Massachusetts Avenue, Cambridge, MA 02139 e-mail: tah at 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 MIT1472p.SNX RNAAC combination sinex file from all available analysis centers with the GNAAC sinex files. MIT1472p.SUM Name of this summary file 0.0 Starting Week 1395, adopted IGS05 for reference frame. The combination is now minimum constraint. 0.1 Starting Week 1239 we adopted IGb00 reference system (given in IGS03P33_RS99.snx) 0.2 Starting Week 1016 we starting using ITRF97 0.3 Starting Week 0939 we starting using ITRF96 and its reference site list. 0.4 Starting Week 0901 we started using a new apriori file not Non-ITRF94 coordinates based on the analysis of week 0822-0900 sinex files. This change will effect the corrdinate corrections given in this summary. 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) Reference frame is defined translation, rotation to the IGS05 reference frame defined with the following sites: vesl vill madr sfer rabt asc1 hofn mas1 reyk pdel chpi qaq1 braz kely stjo ohi2 ohi3 lpgs alrt hlfx cord cro1 unsa sch2 riog thu3 sant wes2 conz nrc1 scub gode usno algo mana glps nlib chur dubo flin mdo1 amc2 pie1 ispa yell gold holm drao quin will whit thti mkea hnlc kokb aspa chat mcm4 bili noum mac1 petp tidb hob2 tow2 lae1 guam yssk tskb alic cedu jab1 darw tixi daej pimo karr bjfs pert yar1 wuhn cas1 ulab irkt kunm coco lhaz nril guao novj hyde dav1 iisc pol2 dgar kerg kit3 maw1 artu reun sey1 bahr mali trab syog mdvj ramo polv nico mbar glsv harb hrao mets joze suth tro1 trom bor1 mate not1 pots wtzr onsa nya1 nyal nklg cagl zimm gras wsrt brus 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 1472 IMPACT OF RNAACs on GNAAC Loose solution RMS change over 356 stations: 0.15 mm CENTER RESULTS For Center GSI VARIANCE FACTOR 1 Site dN +- dE +- dU +- Center (mm) (mm) (mm) (mm) (mm) (mm) AIRA 1.9 0.7 1.4 0.7 -6.3 2.8 Center GSI KNYA 3.1 0.6 -1.1 0.6 -2.5 2.4 Center GSI MZSW 3.1 0.6 2.7 0.5 -15.4 1.9 Center GSI P118 2.9 0.6 1.6 0.6 -13.4 2.3 Center GSI P124 3.1 0.6 2.6 0.6 -2.4 2.2 Center GSI STK2 9.7 0.6 -6.5 0.5 -6.9 1.8 Center GSI TSK2 2.2 0.6 1.2 0.5 12.0 2.0 Center GSI