****************************************************************************** BSW Electronic Mail 14-Jan-1999 10:35:02 CET Message Number 0053 ****************************************************************************** AUTHOR: Rolf Dach Subject: Problems with the simulation program Dear colleagues, we 've found a bug in the Bernese Software Version 4.0: Because of the possibility to start a new arc in the ORBGEN program the satellite n can be found twice (or even more times) in the standard orbit file (1st: SVN n and 2nd: SVN n+50). The simulation program GPSSIM will detect this satellite twice in the standard orbit file and will produce observations for each of these SVNs. Such satellites with a doubled number of observations can influence simulation studies, e.g. of satellite geometries. To prevent this effect you should add the following line to the subroutine SMPRNG.f: C* SUBROUTINE SMPRNG(TITLE,STATIO,XSTAT,PLH,FILMET, 1 NSAT,SVN,ITROPO,TEMP,PRESS,HUM,MAXTBS,RMSTRP, 2 SAMETR,USEMAX,NCLOCK,CLOCK,IONO,XSTION,TFIRST, 3 TLAST,RECTYP,ANTTYP,IANTEN,CSESS, 4 INTER,IELEV,NEPO,PRANG,NOBSVN,IX) CC CC NAME : SMPRNG . . . C C LOOP OVER ALL SATELLITES OF EPOCH IEPO C -------------------------------------- DO 100 ISAT=1,NSAT ccc ccc ignore satelite numbers greater than 50 ccc (they will used allready with their original number) ccc ------------------------------------------------------- if (svn(isat).gt.50) goto 100 C C GET SATELLITE POSITION IN SYSTEM B1950.0 OR J2000.0 CALL GETORB(SVN(ISAT),1,2,1,T-ERRDFR,ICRARC,IORSYS, 1 XSAT,TOSC,ELE,IRC) . . . RETURN END After recompiling this subroutine and updating the archiv-file you had to link the GPSSIM program. =============================================================================== III PPPPPPP GGGGGGG Rolf Dach III PPP PPP GGG GGG III PPP PPP GGG GGG Technische Universitaet Dresden III PPP PPP GGG Institut fuer Planetare Geodaesie III PPPPPPP GGG GGGG D-01062 Dresden, Germany III PPP GGG GGG III PPP GGG GGG Phone: +49-351-463 2854 III PPP GGGGGGG Fax: +49-351-463 7063 E-mail: dach@ipg.geo.tu-dresden.de =============================================================================== [Mailed from: Rolf Dach ]