Instrument¶
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class
msumastro.header_processing.feder.
Instrument
(name, fits_names=None, rows=0, columns=0, image_unit=None, trim_region=None, useful_overscan_region=None)[source]¶ Bases:
object
Telescope instrument with simple properties.
Parameters: name : str
Name of the instrument.
fits_names : list of str
List of names by which the instrument is known in FITS headers
rows : int
Number of rows in an image produced by this instrument, including overscan.
columns : int
Number of columns in an image produced by this instrument, including overscan.
image_unit : astropy.units.Unit
Unit of the image; default value is
None
trim_region : string
Region of the CCD that should be preserved after overscan subtraction. Should use FITS conventions for specifying slices (i.e. slice starts at 1, includes endpoint, and uses FITS NAXIS1, NAXIS2 for order of indices).
useful_overscan_region : string
Complete specification of the region of the CCD actually useful for overscan calibration. This may (or may not) be smaller than the entire portion of the chip the manufacturer labels as overscan. Should use FITS conventions for specifying slices (i.e. slice starts at 1, includes endpoint, and uses FITS NAXIS1, NAXIS2 for order of indices).
Examples
Consider an image whose dimensions as given in its FITS header are
NAXIS1 = 3085
andNAXIS2 = 2048
with an overscan region that begins at position 3073 along axis 1. The useful part of that overscan is from FITS column 3076 up to and including, 3079, and the full range of rows (NAXIS2
). The correct overscan settings for this instrument are:# Note not all of the overscan region is actually useful. useful_overscan_region = '[3076:3079, :]' # But the whole overscan region should be trimmed away in reduction. trim_region = '[1:3073, :]'
Methods Summary
has_overscan
(image_dimensions)Determine whether an image taken by this instrument has overscan Methods Documentation
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has_overscan
(image_dimensions)[source]¶ Determine whether an image taken by this instrument has overscan
Parameters: image_dimensions : list-like with two elements
Shape of the image; can be any type as long as it has two elements. The order should be the FITS order,
NAXIS1
thenNAXIS2
.Returns: bool
Indicates whether or not image has overscan present.
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