Last modified: 7 November 2022

URL: https://cxc.cfa.harvard.edu/ciao/caveats/acis_interleave.html

Time Keywords in Interleaved Data


Prior to version DS 6.9 of the standard data processing software, there was an error in the pipeline derivation of the DTCOR value, which resulted in incorrect values for the time header keywords. Users working with interleaved data processed before this software version will need to calculate the correct time values and change the header with dmhedit. The processing version is stored in the ASCDSVER header keyword.

More information on each of the keywords is available in "ahelp chandra times". The following equations should be used to determine the correct values: