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Дата изменения: Wed Jul 2 02:04:09 2008 Дата индексирования: Fri Sep 5 20:42:04 2008 Кодировка: Поисковые слова: http www.iki.rssi.ru |
The Observation Data File (ODF) distributed to the guest observer contains a summary file (SF), whose structure is described in the ODF Interface Control Document [1].
The SF does not contain all the information required to process the ODF with the SAS. odfingest extends the SF with data extracted from the instrument housekeeping data files and the calibration database. It creates a new summary file: the SAS ODF Summary File (SOSF).
The user would subsequently set the environment variable SAS_ODF to point to the location of the SOSF. See the OAL documentation for more details.
odfingest operates on a directory (specified with odfdir) containing one ODF.
The user need not have write access to the ODF directory. odfingest uses the parameter outdir to learn where to write the SOSF. If the output directory and te ODF directory are different it is useful to instruct odfingest to write in the SOSF the path to the ODF directory. This behavior is controlled via the parameter writepath, and is enabled by default.
By default odfingest automatically generates a ``canonical'' name for the SOSF, namely one that (almost) complies with the file naming convention specified in the ODF ICD [1]. The name of the canonical SOSF differs from the one given in the ODF ICD only by the suffix: .SAS instead of .ASC. (See also the examples below.)
Alternatively, the name of the SOSF can be passed to odfingest with the parameter summaryfile. For this to be effective usecanonicalname should be set to no.
Note that specifying the name of the SOSF may render the SAS unusable. Do not make use of this functionality unless you know what you are doing.
odfingest examines all the files in the ODF directory and from those it reconstructs the structure of the observation in terms of exposures. For each exposure it determines the start and stop times. These are then used to inspect the instrument housekeeping and extract the parameters described in Section 4.
The extraction of housekeeping parameters can be inhibited by setting usehousekeeping to no. This should be done only if there is a good reason for it, and again it might make parts of the SAS unable to operate correctly.
By default odfingest tries to determine the instrument mode during each exposure. This requires access to the Calibration Access Layer (cal) and a suitable Calibration Index File (see cifbuild). This computation is controlled with the parameter findinstrumentmodes. Disabling the determination of the instrument modes should not prevent any SAS task from working correctly.
Finally, it is possible to ask odfingest to perform a number of checks on the newly created SOSF. These checks are activated with the parameter oalcheck, and are:
XMM-Newton SOC/SSC -- 2008-07-01