MIRAPROC Keyword

The MIRAPROC keyword is used by the Express Image Calibration command to encode calibration information into the FITS header. This keyword has a string value with "0" and "1" characters at assigned position to encode the success of each calibration step. Initially, the string is all zero's, but each calibration step sets a "1" digit at a position for that calibration step. For example, a simple bias frame subtraction enters a "1" at position 0, on the left end of the keyword string. This is also used by Mira to block repeat application of specific calibration steps. The string is only as long as needed and expands its length as necessary.

Example

Suppose the Express Image Calibration command applies a bias frame, applies a dark frame after scaling by exposure time, and applies a master flat frame. According to the table below, the image header would add a MIRAPROC keyword line with a "1" in positions 0, 9, and 14:

MIRAPROC '100000000100001'

If you ran another calibration to apply only a pixel mask, the MIRAPROC keyword would update as follows:

MIRAPROC '1000000001000010000000001'

MIRAPROC Calibration Flags and Positions

The table below lists the currently used processing flags. Note that the first string position is at position 0, on the left end of the string. Some processing flags shown below are not used to allow for future expansion

Processing Flag	Position
Apply bias frame	0
Apply pattern bias frame (unused)	1
Apply bias value	2
Apply column bias	3
Apply row bias	4
Apply erase line bias	5

Apply dark frame	8
Apply scaled dark frame	9
Apply optimized dark frame	10
Apply nearest dark frame (unused)	11

Apply master flat frame	14
Apply illumination flat frame	15
Apply pixel flat frame	16

Combine multiple images	20
Normalize image	21

Apply pixel mask	24
Apply region mask	25
Apply cosmic ray filter	26
Trim image to smaller size	27

Subtract background fit	30
Divide background fit	31

Example

MIRAPROC Calibration Flags and Positions

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