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: http://xmm.vilspa.esa.es/sas/7.0.0/doc/omichain/node3.html
Дата изменения: Thu Jun 29 01:23:20 2006 Дата индексирования: Sat Dec 22 09:36:42 2007 Кодировка: Поисковые слова: deep sky |
This package contains a PERL script which takes a set of image mode OM ODF files in a single directory and processes them in a pipeline to produce OM image mode pipeline products see Section 9 . Given a directory with a set of ODF files that conform to the filename specification given in the ODF ICD the PERL script will process the image files and output files conforming to the ICD specifications.
Through reading the SAS summary file, the perl scrip first produces a list of the filters for the OM data. The perl-script loops through each filter and produces a list of exposures for the filter to be processed.
This is followed by the creation of the flatfield (currently a static flat from the CAL data) by omflatgen.
The chain then scans the input area to check that the necessary auxilliary files (e.g. tracking history, window files, housekeeping files etc) are present, exiting if any key files are absent.
Figure 1 shows the overall operation of the omichain
Omichain then cycles through each exposure for the filter being processed. It first checks to see if the exposure is a full-frame low resolution mode, and if so it runs omcomb to combine the four separate image segments into a single full-frame image.
The tracking-history pipeline is run to produce tracking history information using omprep, omdrifthist and omthconv.
The imaging pipeline is then run to reduce the exposure image
(2 for Rudi-5 and 1 for Engineering-2 data), using omprep, omcosflag, omflatfield, ommodmap, omdetect, ommag and omatt. When all the exposures for a given filter have been processed, ommosaic is used to combine the low-resolution sky-coordinate images into a single full-field image.
Finally, outside the filter processing loop, omsrclistcomb runs to combine the source lists from separate exposures into a single master list.
(2 for Rudi-5 and 1 for Engineering-2 data), using omprep, omcosflag, omflatfield, ommodmap, omdetect, ommag and omatt. When all the exposures for a given filter have been processed, ommosaic is used to combine the low-resolution sky-coordinate images into a single full-field image.
Finally, outside the filter processing loop, omsrclistcomb runs to combine the source lists from separate exposures into a single master list.
Using the default parameter settings the omichain will process all the image files in the data directory. However, if only the images of particular exposures are required to be processed, or the images for particular filters, the parameters exposures and filters, respectively, can be used to achieve this.
Some of the parameters for individual tasks can be set using the appropriate omichain parameter - the parameter names are the same as the task name, prefixed with the name of the task.
Figure 2 shows the operation of the tracking-history pipeline and also that of the imaging pipeline
