XMM-NEWTON DATA REDUCTION WALK-THROUGH, SIMPLIFIED
SAS Installation and Environmental Parameters
Many SAS tasks require calibration information from the Calibration Access Layer (CAL). Relevant files are accessed from the set of Current Calibration File (CCF) data using a CCF Index File (CIF). A CIF is included in the pipeline products (*CALIND*), but if the CCF has been updated it can be recreated by the user by simply typing
5.1 cifbuild
Many SAS tasks require calibration information from the Calibration Access Layer (CAL). Relevant files are accessed from the set of Current Calibration File (CCF) data using a CCF Index File (CIF). A CIF is included in the pipeline products (*CALIND*), but if the CCF has been updated it can be recreated by the user by simply typing
cd ODF
cifbuild
The task cifdiff can be used to compare the new CIF with the old:
- cifdiff calindex1set=ccf.cif calindex2set=CALIND.FIT
where
- calindex1set - name of the first file to be compared,
in this case the output from
the current run of cifbuild
- calindex2set - name of the second file to be compared,
in this case the (renamed)
pipepine product file
- calindex1set - name of the first file to be compared,
in this case the output from
If the CAL has changed, it is a good idea to repipeline the data using the new CIF. To help determine whether it is reasonable to repipeline the data, the CCF release notes should be examined (see §2.5). CCF files can be downloaded directly from the SOC website see (see §4.2).
To use the updated CIF file in further processing, you will need to reset the environment variable SAS_CCF:
- setenv SAS_CCF /full/path/to/ODF/ccf.cif
5.2 odfingest
The task odfingest extends the Observation Data File (ODF) summary file with data extracted from the instrument housekeeping data files and the calibration database. It is only necessary to run it once on any dataset, and will cause problems if it is run a second time. If for some reason odfingest must be rerun, you must first delete the earlier file it produced. This file largely follows the naming convention described in §3.3.3, but has SUM.SAS appended to it. After running odfingest, you will need to reset the environment variable SAS_ODF to its output file. To run odfingest and reset the environment variable, simply type:
- odfingest
- setenv SAS_ODF /full/path/to/ODF/full_name_of_*SUM.SAS
The user will likely find it useful to alias these environment variable resets in their login shell (.cshrc, .bashrc, etc.).
The rest of this guide consists of step-by-step examples of how to reprocess and analyze data for the EPIC (§6), RGS (§7), and OM (§8). At the start of each chapter, it is assumed that the user has downloaded the data, initialized SAS, and set the environment variables, as listed in 4.3. It is also assumed that the CIF file is up-to-date, the *SUM.SAS file exists, and the appropriate environment variables reset as needed.
Next: 6. An EPIC Data Up: XMM ABC Guide Previous: 4. Setting Up and Contents Lynne Valencic 2014-04-17