Chandra Calibration Database

Introduction: Header Keywords; Directory Structure; Indexing System; Versioning
Download the CALDB: Download Version 3.4.3; Release Notes
Caveats for the Chandra CALDB: ACIS N0005 Responses Suite Caveat
Querying the CALDB
Calibration Data
Proposal Planning
References
CXC Links: CIAO (Data Analysis)
Site Map

Analysis Notes

Matching CIAO and CALDB Versions

CALDB 3.4.3 should not be used unless you are running CIAO 3.4 or CIAO 4.0.

Are your versions mismatched? Time to update CIAO and CALDB!

News

31 Mar 2008 [New]

CalDB 3.4.3, an upgrade to CalDB 3.3.0 or later versions, which introduces ACIS -110C "Epoch 0" T_GAINs for ACIS-S1 and -S3, and ACIS -120C EPOCH 32 (Nov 07 - Jan 08) T_GAIN updates, has been released to the public. See the CalDB 3.4.3 release notes for more information on this upgrade.

14 Dec 2007

CalDB 3.4.2, an upgrade to CalDB 3.3.0 or later versions, which updates ACIS T_GAINs for Aug - Oct 2007, has been released to the public. See the CalDB 3.4.2 release notes for more information on this upgrade.

14 Sep 2007

CalDB 3.4.1, an upgrade to CalDB 3.3.0 or later versions, which introduces new and finalized ACIS blank sky, T_GAIN, and HRC-I DEGAP files, has been released to the public. See the CalDB 3.4.1 release notes for more information on this upgrade.

16 May 2007

CalDB 3.4.0, an upgrade to CalDB 3.3.0/3.3.0.1, which introduces new ACIS T_GAIN, grating mask files, as well as upgrades to HRC-I GMAPS and HRC-S QE, has been released to the public. See the CalDB 3.4.0 release notes for more information on this upgrade.

Welcome to the
Chandra Calibration Database Website

The Chandra X-Ray Center introduced version 3.4.3 of the Chandra Calibration Database (CALDB) on 31 Mar 2008.

CALDB 3.4.3 is a cumulative upgrade to CalDB 3.3.0 or later versions; It includes the following:

Upgraded ACIS -120C time-dependent gain (T_GAIN) data for Epoch 32 (Nov 2007 through Jan 2008).
Newly introduced -110C time-dependent gain (T_GAIN) corrections for Epoch 0 (19 Sep 1999 through 28 Jan 2000) for the BI chips ACIS-S1 and ACIS-S3 only. The concurrent release of a new corresponding gain (DET_GAIN) file for -110C enables users to apply the improved BI chip gain functions, and to use mkacisrmf to generate improved RMFs for BI chip data taken in Epoch 0. The improved S1 gain function also helps with order-sorting of -110C ACIS/grating observations.

See details in the link CalDB 3.4.3 Release Notes.

The CALDB is the directory and indexing structure that stores and provides access to all calibration files that are required for standard processing and analysis.

These files are used in standard data processing, as well as for analysis with software packages such as CIAO. When you apply a gain map, create an exposure map, or build response files (RMFs and ARFs) - among many other things - you are using the Chandra CALDB to apply the necessary calibration files.

The CALDB serves many functions:

Storing and archiving calibration files.

Maintaining a naming convention and header structure for all calibration files.

Indexing calibration data, based on FITS header keywords, for software access.

Permitting updates of calibration data independent of software updates, while maintaining configuration control.

Providing a traceable history of calibration data in the database by maintaining versioning.

Translating calibration products into formats suitable for processing and/or analysis.

These webpages contain information about each of these topics. They are also designed to help you (or your system manager) understand how the CALDB is assembled and how it works in the Chandra software system.

Please email the CXC Helpdesk with any questions or comments on the CALDB and this website.

Analysis Notes

Matching CIAO and CALDB Versions

News

Welcome to the Chandra Calibration Database Website

Welcome to the
Chandra Calibration Database Website