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Last modified: 11 December 2019


CalDB Release Notes

NOTICE: CalDB has not been released to the public.

SDP Installation Date: 2019-10-02T14:00:00 (UTC)


CalDB is an upgrade to the Chandra CalDB, which includes the following items:

For the CIAO 4.12 / CalDB release notes see How CalDB Affects Your Analysis.


A. HRC-S GAPLOOKUP Version N0006

Location: $CALDB/data/chandra/hrc/gaplookup/
Filename: hrcsD1999-07-22gaplookupN0006.fits

As per the CalDB 4.8.3 release notes, a fix has been released in the HRC-S GAPLOOKUP table (version N0005) as of 23 May 2019 to correct a small error in the U-direction positions of the HRC-S plate edges. These plate edge position corrections were implemented as keywords (HRC_OFF_X and HRC_OFF_Y) in the corresponding GAPLOOKUP BINTABLE headers (U-direction only).

After the release of CalDB 4.8.3 , it was pointed out internally that the two new keyword names HRC_OFF_X and HRC_OFF_Y are actually nine characters long instead of the FITS interoperability requirement of 4 to 8 characters. We have since agreed that these keyword names should be corrected in both cases. The modified keyword names are HRC_OFFX and HRC_OFFY, and have been implemented in the HRC-S GAPLOOKUP file version N0006. The old keywords have been removed.

The keyword name changes require that the software (specifically hrc_process_events) be modified as well. For Standard Data Processing, this change was included in DS10.8.1, released on 02 October 2019. Hence CalDB was installed simultaneiously in processing with the DS 10.8.1 installation. For CIAO, the modification to hrc_process_events is to be released with CIAO 4.12 on 17 December 2019. A simultaneous CalDB upgrade including the updated GAPLOOKUP file above will be required.

For technical details, see the CalDB 4.8.3 release notes under Technical Details Section C, "HRC-S GAPLOOKUP Table Keword Additions".


HRC Level 1 processing tool hrc_process_events

CIAO script chandra_repro uses hrc_process_events to reprocess HRC-S observation data. Only HRC-S data are affected by this change.


Reprocessing Data to Create a New Level=2 Event File for HRC-S data sets only.