ROSAT Status Report #76:
December 15, 1993
ROSAT Sequence-naming Conventions
As ROSAT data processing software has been upgraded during the course of the mission, the sequence-naming conventions have evolved. The following is a summary of these conventions. Note that the term "U.S. FITS" refers to the FITS format that is currently distributed by the U.S. ROSAT Science Data Center (RSDC).
A key difference between data processed during Rev0 and those processed during Rev1 pertains to the way separate observation intervals (called "OBIs") are combined. During Rev0, all available OBIs were used to produce a single set of data products. On the other hand, during Rev1, OBIs which were part of the same sequence but which occurred in different "observing seasons" (i.e., ~6 months apart) were processed and distributed separately.
A further distinction exists between "processing" and "Reprocessing". In order to make the entire ROSAT data stream available as Rev1 data products (in RDF format - cf. section 3 below), observations whose data were previously processed only with Rev0 SASS will be reprocessed (beginning in early 1994) to provide Rev1 data products. (Note that observations processed for the first time using Rev1 SASS to generate RDF data products will not require reprocessing.)
The following diagram illustrates this situation:
time SASS 3_0 Rev 0 U.S. FITS RODFITS || | | | (MPE) || | | | | || SASS 5_9 | | | || ------------ - - --------- - - ----------- 27 Jan 93 --------- || SASS 6_0 Rev 1 | | || | | | | || | | | | || SASS 6_9 | | | || ------------ - - --------- - - ----------- ~1 Mar 94 --------- || SASS 7_0 Rev 2 RDF >---->+<-----< RDF || | | | || | | RDF || | | | || . . . || . . . \/ . . .
1. U.S. Revision 0 names
The following naming conventions apply to all data processed by the U.S. RSDC using SASS versions 3_0 through 5_9 (Rev0) and distributed in the U.S. FITS format. As stated above, during Rev0 all available OBIs were used to produce a single set of data products, regardless of whether or not they occurred in different "observing seasons".
Rev0 file names are of the form:
where: r - stands for ROSAT
For example, the photon event files produced by IRAF/PROS from Rev0 data products might be:
2. U.S. Revision 1 names
The following naming conventions apply to all data processed by the U.S. RSDC using the SASS versions 6_0 and greater (Rev1) and distributed in the U.S. FITS format, i.e., data products produced after January 27, 1993.
During Rev1 processing, observations conducted over different "observing seasons" (i.e., over gaps of several months) are no longer combined to form a single data set. Additional observations, known as "add-ons", are processed separately. The sequence-naming convention for Rev1 (U.S. FITS) file names is as follows:
where the two additional digits added after the ROR number are:
For example, Rev1 IRAF/PROS "qpoe" file names might be:
3. Rationalized Data Format names
A new data-product format, RDF (Rationalized Data Format; expected to be introduced in January 1994), will unify the German and U.S. FITS formats used previously into a single set of formats, necessitating a further change in naming conventions. All U.S. data processed prior to January 1994 (regardless of whether processed with Rev0 or Rev1 SASS) will be Reprocessed using the latest Rev1 software in order to produce RDF FITS data products for the public data archive.
An additional identifier has been inserted into the RDF file names to indicate both "split" Rev0 sequences and "mispointed" observations (those for which the telescope was not pointed at the intended target). The RDF FITS file names have the form:
where
In this case, the IRAF/PROS name for RDF-format "qpoe" files might be:
The process of preparing detailed Validation and Verification (V&V)
Reports for ROSAT data before delivery to GOs was terminated in
mid-October (1993) due to RSDC project funding cuts. In its place,
however, (in mid-November) we instituted an automated check of
important data files for all observations. Reports for data sets
processed between the above two dates (for which the GOs did not
receive a V&V report) are available on request from the SAO-RSDC
(email request to: rsdc@cfa.harvard.edu).
The automated V&V process generates a single-page report and, if
relevant, a comparison of key parameters (such as exposure times,
background rates, and number of detected sources) between the current
and the previous processing of the same data set. The check also
includes a search for missing files and verification that the
RDF-format FITS files translate into IRAF without errors. The
existence of a V&V report thus ensures that the data are all present
and readable by IRAF/PROS.
Curator:
Status of Validation and Verification of the ROSAT Data.
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