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BeppoSAX U.S. Coordination Facility

BeppoSAX Data Archive :
Coordinates Correction


A ~20 arc sec systematic error that affects LECS and MECS coordinates has been identified and a detailed discussion is given in the technical report "An improvement of BeppoSAX LECS and MECS source positioning accuracy" (HTML or PS version). A brief discussion of the problem and the solution is available also on the web

The BeppoSAX data delivered by the ASDC-BeppoSAX at the HEASARC archive do not have this correction applied.
All LECS and MECS event files retrieved from the ASDC archive , after March 12 2002, have this correction already applied.

The BeppoSAX-ASDC provided a script "saxposcor" that applies the correction to the LECS and MECS event files and updates the WCS keywords. The "saxposcor" should be applied to all LECS and MECS event files retrieved from the HEASARC archive and processed before March 12 2002. The processing date is stored in the keyword header DATE of the fits file (use the FTOOLS fkeyprint as 'fkeyprint filename DATE').

saxposcor is a tcl script. It needs the FTOOLS package to run and corrects any BeppoSAX-NFI event file (LECS, MECS1, MECS2, MECS3, MECS23 and MECS), e.g. it does not work on the images. To use saxposcor retrieve the following two files:

           saxposcor
           saxposcor.par

The usage of saxposcor is the following:

saxposcor  filename=MECS2_00000000.evt  indir=path


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This file was last modified on Tuesday, 15-Jan-2008 11:43:15 EST