Modify Keywords

The Modify Keywords command adds, modifies, or renames keyword metadata in the image header. This command works with any displayed image and with image files opened from a FITS format file. New keyword data may be added, existing keywords may be modified, and keyword names may be changed to other names. If Action = Add and the keyword already exists in the image header, its value is replaced by the value in the table.

The Modify Keywords command opens from the Image Window > Process > Calibrationmenu and button on the Main Toolbar. The "immediate" form, shown first, opens when an image or image set is displayed in the top-most window. The general form can be used to select source images from folders, windows, or by matching templates.

Modify Keywords Properties

Profile	Select a profile to save and preset the table entries.
[Select]	Opens the Select Source Images dialog to choose images from an image window, folder, files, name template, or a Mira File List.

Action	Specifies the action to take for the specified keyword. Add If the Keyword does not exist in the image header, it is added. If the Keyword already exists in the image header, its value is changed to the entered Value. Rename If the named Keyword exists in the image header, its name is changed to the specified Value. The Comment is not used. (none) Specifies that there is no action taken for this line of the table. Use this option if you want to keep a keyword in the list but not apply it at the current time.
Type	Specifies the type of keyword as a String, Number, or Integer. These are described a separate table below.
Keyword	Specifies the name of the Keyword. You can use either a standard or conventional name or your own private keyword name. For list of standard and conventional keywords, see FITS Keywords.
Value	Specifies the keyword change to be made in the header. What is changed depends on the Action. Add (Action): The Value is saved as the new value of the keyword. Rename (Action): The Value replaces the keyword name. The previous value and comment in the image header are preserved.
Comment	Optionally, for a new keyword. The comment is saved only when Action=Add. The comment is ignored for Action=Rename.

Keyword Types

The Type of a keyword refers to the kind of value that will be saved in the image header.

String	The keyword value is saved as a string between single quotes. The String type is also used for date, time, and angle in HMS/DMS format. Example: 'My great data' '-30:12:14.566'
Number	The keyword is saved as a real (floating point) number including a decimal point or exponential notation. Examples: -1.456E-12 825.421 152.
Integer	The keyword is saved as an integer value with no decimal point. Examples: 68455 -452
Logical	The keyword is saved as a logical (Boolean) value, either T or F. The SIMPLE keyword is a typical example of this type of value.

Keyword Types

Related Topics