SMAS

Short Map Analysis Script

Description:

With the exception of Moon maps, each NDF is processed in the same way. The KAPPA:PSF command is used to locate the accurate source centre and fit it using an elliptical Gaussian-like model. The details of the model are then appended to an output text file as a new row.

The resulting output catalogue has a row for every input NDF, and contains the following columns:

For comparison, a set of extra columns is appended to these that give the source properties as calculated by KAPPA:BEAMFIT rather than KAPPA:PSF. These columns have the same names, but are prefixed by the letter B. Note, BEAMFIT assumes a gamma value of 2.0 (i.e. a pure Gaussian) and so there is no BGAMMA column in the output catalogue.

The SEQSTART and SEQEND columns will be set to ‘null’ if the supplied map does not contain these FITS headers.

If the supplied data is for the Moon, then all the above is ignored and the output contains the following columns:

Usage:

smas [-a diam] [-b] [-e error] [-r perc] [-p] <in-list> <out-table> [<out-image>]

Parameters:

−a
Specifies that the catalogue SUM column values (the total data sum) should be the integrated data value within a circular aperture centred on the source peak position, with radius specified by “diam” (a numerical value in arc-seconds). This is calculated using KAPPA:APERADD. If this option is not supplied, the SUM value is the integrated value under the model source calculated by KAPPA:PSF. If “diam” is not supplied, defaults of 30 and 15 are used for 850 and 450 μm data respectively.
−b
Specifies that the catalogue should contain only ROW, COL and AMP only. Using this option also implies the “−p” option. This reduces the run-time for script significantly.
−e
Specifies the maximum allowed error (in arc-seconds) between the source position as determined by KAPPA:BEAMFIT and KAPPA:PSF. If the discrepancy in X or Y is greater than this value, then the shortmap or bolomap is not included in the returned catalogue or image. If the −e option is unspecified, then no sources are rejected. If no “error” value is supplied, a default of 1 arc-second is used.
−p
Specifies that the catalogue AMP column values (the peak value in the source) should be the maximum data value within a box of size 20 pixels centred on the expected source position. If this option is not supplied, the AMP value is the peak value of the model source calculated by KAPPA:PSF.
−r
The following number (“perc”) specifies the minimum percentage of good pixel values in a small box around the expected source position. Sources that have insufficient good pixels in the box are reported and then ignored. If the “-r” option is not supplied (or is supplied without a "perc" value), a default of 95 is used.
<in-list >
The path to an NDF holding a SCUBA-2 map of a point source (or Moon). Alternativelty, a text file containing the paths to one or more such NDFs can be supplied. If an NDF contains a MORE.SMURF.SHORTMAPS or MORE.SMURF.BOLOMAPS extension item, then the NDFs in the SHORTMAPS or BOLOMAPS array are used in place of the supplied NDF (SHORTMAPS is used in preference to BOLOMAPS if both are present). Note, all the data must be for the same wavelength.
<out-table >
The name of a text file in which to store a catalogue containing details of the source in each supplied map, as described below. This catalogue can be displayed and analysed using topcat -f ascii <out-table >.
<out-image >
If supplied, and if the input data contains bolomaps, a 2D NDF containing the SUM (or AMP if the “−b” option is used) values for each bolometer is created with the name given by <out-image >. The FITS headers from the first input NDF are copied to the output NDF. If the supplied data contains values from more than one sub-array, the name of the sub-array is appended the end of each output NDF name.
Copyright © 2012 University of British Columbia & the Science & Technology Facilities Council