<param type="string" name="interp" subparam="true"><shortdescription>Interpolation type in time[,freq]. Valid options for time are "nearest", "linear", and "cubic", while valid options for frequency include "nearest", "linear", "cspline", or any numeric string that indicates an order of polynomial interpolation. You can specify interpolation type for time and frequency separately by joining two of the above options by comma (e.g., "linear,cspline").</shortdescription><description>Interpolation type in time[,freq]. Valid options for time are "nearest", "linear", and "cubic", while valid options for frequency include "nearest", "linear", "cspline", or any numeric string that indicates an order of polynomial interpolation. You can specify interpolation type for time and frequency separately by joining two of the above options by comma (e.g., "linear,cspline").</description>
<casaxml xsi:schemaLocation="http://casa.nrao.edu/schema/casa.xsd file:///opt/casa/code/xmlcasa/xml/casa.xsd" xmlns="http://casa.nrao.edu/schema/psetTypes.html" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<task type="function" name="sdcal" category="single dish">
<shortdescription> MS SD calibration task</shortdescription>
Task sdcal implements a single-dish data calibration scheme similar to that of
interferometry, i.e., generate calibration tables (caltables) and apply them.
Available calibration modes are:
'ps', 'otfraster', 'otf' for sky calibration
'tsys' for Tsys calibration
Each mode generates a caltable.
Caltables can be applied to the data by combining calibration
modes with the keyword 'apply'.
Calibration is applicable for fast moving source even like the moon which moves
quickly outside of the field of view (see the note of 'otf' mode in below).
Calibration mode must be set in accordance with the observing mode
of the data. Use case for each mode is as follows:
'ps': position switch (including OTF) with explicit
'otfraster': raster OTF scan without explicit OFFs
'otf': non-raster OTF (e.g. double-circle) scan without explicit OFFs
So, if the data contains explicit reference spectra, 'ps' should
be used. Otherwise, 'otfraster' or 'otf' should be used.
In 'otfraster' and 'otf' modes, an edge marker automatically marks spectra from
specific regions of the observation pattern as reference (OFF) spectra.
These specific regions are:
- in 'otfraster' mode: regions near the beginning and the end of the raster
- in 'otf' mode: regions near the periphery of the observation pattern.
Note: The 'otfraster' mode is designed for OTF observations without explicit OFF
spectra. However, it should work even if explicit reference spectra exist.
In that case, these spectra are ignored and spectra marked by edge marker are
Note: Detection of periphery scans in 'otf' mode is available for fast moving
sources, e.g., Sun, Moon. It is often the case antennas keep track of source motion
during the observations of moving sources so that the source is always at the map center.
In order to handle such observations, pheriphery search is done in the source frame
for known moving sources, in which the source is always at a rest position.
Apart from the way reference spectra are selected, the procedure to derive
calibrated spectra is the same for all modes. Selected (or preset)
OFF integrations are separated based on continuity in time domain,
averaged in each segment, and then interpolated to timestamps for ON
integrations. Effectively, it means that OFF integrations are
averaged by each OFF spectrum for 'ps' mode, averaged by either ends
of each raster row for 'otfraster' mode. The formula for calibrated
<param type="path" name="infile" mustexist="true"><shortdescription>name of input SD dataset (must be MS)</shortdescription><description>name of input SD dataset (must be MS)</description>