CATDagger

A catalog source differential gain tagger based on local noise characteristics

This tool segments regions within residual images that are in need of a differential gain. Preferably the tool is run on stokes V residuals, which typically contain relatively little real flux and mostly residual calibration errors. In principle it can also be run on Stokes I residuals if direction independent calibration was successful.

DS9 region maps containing regions and cluster lead information is output by default as shown as example below. Tigger LSM catalogs can simultaniously be processed and reclustered based on identified dE regions.

Usage

dagger --help usage: CATDagger - an automatic differential gain tagger (C) SARAO, Benjamin Hugo 2019

[-h] [--stokes STOKES] [--min-tiles-region MIN_TILES_REGION] [--input-lsm INPUT_LSM] [--ds9-reg-file DS9_REG_FILE] [--ds9-tag-reg-file DS9_TAG_REG_FILE] [-s SIGMA] [--tile-size TILE_SIZE] [--global-rms-percentile GLOBAL_RMS_PERCENTILE] [--de-tag-name DE_TAG_NAME] [--min-distance-from-tracking-centre MIN_DISTANCE_FROM_TRACKING_CENTRE] [--add-custom-exclusion-zone ADD_CUSTOM_EXCLUSION_ZONE [ADD_CUSTOM_EXCLUSION_ZONE ...]] [--max-region-right-skewness MAX_REGION_RIGHT_SKEWNESS] [--psf-image PSF_IMAGE] [--remove-tagged-dE-components-from-model-images REMOVE_TAGGED_DE_COMPONENTS_FROM_MODEL_IMAGES] [--only-dEs-in-lsm] [--max-positive-to-negative-flux MAX_POSITIVE_TO_NEGATIVE_FLUX] [--max-region-abs-skewness MAX_REGION_ABS_SKEWNESS] noise_map

positional arguments:

noise_map Residual / noise FITS map to use for estimating local

RMS

optional arguments:

-h, --help	show this help message and exit
--stokes STOKES
	Stokes to consider when computing global noise estimates. Ideally this should be 'V', if available
--min-tiles-region MIN_TILES_REGION
	Minimum number of tiles per region. Regions with fewer tiles will not be tagged as dE
--input-lsm INPUT_LSM
	Tigger LSM to recluster and tag. If this is not specified only DS9 regions will be written out
--ds9-reg-file DS9_REG_FILE
	SAODS9 regions filename to write out
--ds9-tag-reg-file DS9_TAG_REG_FILE
	SAODS9 regions filename to contain tagged cluster leads as circles
-s SIGMA, --sigma SIGMA
	Threshold to use in detecting outlier regions
--tile-size TILE_SIZE
	Number of pixels per region tile axis
--global-rms-percentile GLOBAL_RMS_PERCENTILE
	Percentile tiles to consider for global rms calculations
--de-tag-name DE_TAG_NAME
	Tag name to use for tagged sources in tigger LSM
--min-distance-from-tracking-centre MIN_DISTANCE_FROM_TRACKING_CENTRE
	Cutoff distance from phase centre in which no tags be raised.This can be used to effectively exclude the FWHM of an parabolic reflector-based interferometer.

--add-custom-exclusion-zone ADD_CUSTOM_EXCLUSION_ZONE [ADD_CUSTOM_EXCLUSION_ZONE ...]

Add manual exclusion zone to which no dE tags shall be added. Expects a tripple of centre X, Y pixel and radius.

--max-region-right-skewness MAX_REGION_RIGHT_SKEWNESS
	The maximum tolerance for right skewness of a pixel distribution within a region.A large value (tailed distribution) indicates significant uncleaned flux remaining in the residual. This can be used to effectively control detection sensitivity to uncleaned extended emission, but should be set to 0 if residuals other than stokes I are used
--psf-image PSF_IMAGE
	PSF image from which BPA, BMAJ and BMIN may be extracted
--remove-tagged-dE-components-from-model-images REMOVE_TAGGED_DE_COMPONENTS_FROM_MODEL_IMAGES
	Blank out model images within resolution of tagged LSM components. Expects list of model FITS files. This option is useful for hybrid DFT-CLEAN component modelling as onlyextended / faint clean components contributes to model.
--only-dEs-in-lsm
	Only store dE tagged sources in lsm. This option is useful for hybrid DFT-CLEAN component modelling, as only bright compact gaussian emission contributes to dE solutions
--max-positive-to-negative-flux MAX_POSITIVE_TO_NEGATIVE_FLUX
	The maximum tolerance for the ratio of positive to negative flux. Only to be used with stokes I
--max-region-abs-skewness MAX_REGION_ABS_SKEWNESS
	The maximum tolerance for absolute skewness of a pixel distribution within a region.A large value (tailed distribution) indicates significant uncleaned flux remaining in the residual. This can be used to effectively control detection sensitivity to uncleaned extended emission, but should be set to 0 if residuals other than stokes Q,U or V are used