Manual header processing

Overview

Sometimes the standard data preparation will fail at one stage or another, most often because pointing information is missing for an image or because no object was found matching the RA/Dec of the image. Your tool of choice in such cases, either to add pointing information or to add object names is quick_add_keys_to_file. A broad discussion of using it is at Fixes for cases that require intervention.

This document provides some examples of using quick_add_keys_to_file from the command line. See the documentation for add_keys() for use from python scripts.

Examples

Command line only

Add the keyword “OBJECT”, with value “EY UMa”, to the file image.fit:

quick_add_keys_to_file.py --key-value object "EY UMa" image.fits

The same, but for all of the files that match the pattern ey-uma*.fit:

quick_add_keys_to_file.py --key-value object "EY UMa" ey-uma*.fits

The rest of the command line examples you have created a file called keys.txt with a list of keyword/value pairs and a list of files called files.txt (you can call the files whatever you want, of course)

Command line and supporting files

Format of the keyword file

A keyword file looks like this (you need the header line):

Keyword,Value
OBJECT,"EY UMa"
RA,"09:02:20.79"
DEC,"+49:49:09.7"

You can include as many keywords as you want, and they can have numerical values instead of string values in appropriate. If the value has two words, like the value for the keyword “OBJECT” above, it must be in quotes, like “EY UMa”.

Keyword names are case insensitive because keywords in the FITS standard are case insensitive.

Format of the file list

A file list looks like this (yes, you need the header line):

File
MyFirstFile.fit
another_fits_file.fits
/or/even/the/full/path/to/a/fits/file.fit

Examples using keyword file/file list

Add all of the keywords in keys.txt to all of the files in files.txt:

quick_add_keys_to_file.py --key-file keys.txt --file-list files.txt

Add all of the keywords in keys.txt to the files image1.fit and image2.fit:

quick_add_keys_to_file.py --key-file keys.txt image1.fit image2.fit

Add keywords from the command line to all of the files in files.txt:

quick_add_keys_to_file.py --key-value my_key "some value" --file-list files.txt