|
|
|
The third reprocessing of Chandra data (REPRO-III) was started in February 2006 and will cover the entire mission. The data will be processed in the following time order:
The quality of the reprocessed data will be better because of improvements in software and, especially, calibrations, since the current default data in the archive were created. Please refer to the Reprocessing III web page for more details: http://cxc.harvard.edu/cda/repro3.html
Whether the new data version would affect any scientific conclusions drawn on the basis of the older versions depends on many factors: the nature of the conclusions, the type of analysis, the signal-to-noise ratio, etc. Ultimately, the user may need to make a comparison in order to judge whether the changes are significant for her or his purposes. To aid in that assessment we have summarized the most significant CalDB and software changes in the above link.
Note also, that the new products will be fully compatible with the current version of CIAO, something that is not necessarily the case for older data versions.
All data are being versioned and stored in the Chandra Data Archive. PIs will receive email notification of data processed within 1 year of the public release date of the observation. All public data are available through WebChaser.
You can check the status of individual Obsids by using the processing Status tool.
Information about data analysis with regard to reprocessing is available from the following web page: http://cxc.harvard.edu/ciao/repro_iii.html
In all, CXC reprocessing consists of three groups. The first part, called REPRO-I (or simply REPRO), was a full end-to-end processing of early observational data with significantly improved software and calibration data. The 2nd part, called REPRO-II, was a partial processing to resolve specific issues for selected ObsIDs. Both ReproI and Repro-II were completed in 2002. Details can be found on the REPRO-I and II page. REPRO-III will cover the entire mission so far and bring all data in line with current calibrations. |
The Chandra X-Ray
Center (CXC) is operated for NASA by the Smithsonian Astrophysical Observatory. 60 Garden Street, Cambridge, MA 02138 USA. Email: cxcweb@head.cfa.harvard.edu Smithsonian Institution, Copyright © 1998-2004. All rights reserved. |
Last modified: 04/13/06