Fixing Raw Fits Headers

At times the raw fits headers have to be updated after the data is taken. As the raw frames are immediatly frozen in their initial state, this is is handled via alternative yanny sdHdrfix-<MJD>.par files. In the era of plate operations, these files were stored in the speclog data product, while in FPS operations, these are stored in the sdsscore data product. The files are read in as part of the pipeline and can be used to correct individual values, or to flag exposures as bad or test, which are then excluded by the pipeline from proceessing.

sdR_hdrfix

The sdR_hdrfix command is used by the observers and pipeline team to create the sdHdrfix yanny files. After the script is run, the created (or appended) sdHdrfix-<MJD>.par files should be manually added the sdsscore repo. The can be done by navigating to $SDHDRFIX_DIR/<obs>/sdHdrfix and git add ..

sphdrfix.pro

The sphdrfix.pro command is used internally by the pipeline and contains internal documentation if one should desire to run it manually, but it can be simply run with sphdrfix, filename, hdr within idl, supplying the filename and raw fits header, and it returns the modified header.

Sphdrfix.py

Sphdrfix.py contains the Sphdrfix Python class that is used by the Python portions of pipeline, where the class is initialized with the MJD (and observatory) of the interest (and other other optional parameters). The class instance function of sphdrfix.fix(filename, hdr), supplying the filename and raw fits header, can be used to which returns the modified header.