Subarrays

Subarrays are exposures captured using a custom rectangular window within the detector array. Subarrays are only supported for the Imager.

The meta keywords of ImagerModel which defines the parameters of the subarray are stored in model.meta.subarray_map:

• name (str): The name of the subarray. This can be “FULL” for full frame or any other name for a subarray.

• id (int): The id of the subarray. This is 0 for full frame and 1 for the first subarray, etc.

• xstart (int): The starting x-coordinate of the subarray in 1-based indexing.

• ystart (int): The starting y-coordinate of the subarray in 1-based indexing.

• xsize (int): The width of the subarray.

• ysize (int): The height of the subarray.

• detysiz (int): The height of the detector (full frame).

• detxsiz (int): The width of the detector (full frame).

• fastaxis (int): The fast axis of the subarray {0,1}.

• slowaxis (int): The slow axis of the subarray {0,1}.

Subarrays and Reference Files

The following reference files support subarrays due to the unique read mode used for that subarray:

• dark: Dark current reference file.

• linearity: Linearity correction reference file.

• saturation: Saturation reference file.

• bias: Superbias reference file.

• gain: Gain reference file.

• readnoise: Read noise reference file.

• ipc: Interpixel capacitance reference file.

• flat: Flat field reference file.

Example

See the test scripts in the DRS tests directory:

• test_imager_stage2.py

• test_parse_subarray_map.py

• test_merge_subarrays.py

• test_create_subarray_dataset.py

• test_dark_subarray.py

Subarray-specific Steps

Many steps use specific processing for subarrays.

• MergeSubarraysStep

• ParseSubarrayMapStep