Release Notes CASA 4.3.
CASA 4.3 has been released and the main feature improvements of CASA 4.3.0 are listed below.
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Note that in its current incarnation CASA is designed to support ALMA, and VLA data, as well as single dish data from ALMA and Nobeyama. Data from other telescopes, be it single dish or interferometers can be imported from uvfits, FITS-IDI , or sdfits formats into measurements sets (ms) or scantables in CASA. Given the variety of non-standard fits formats, we cannot guarantee that CASA will fully support data from all telescopes. However, efforts are made to support data formats from other facilities.
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CASA Release Notes:
Valid for CASA Release 4.3.0 and later: Major improvements over the previous version of CASA include:
- Data examination/editing/import/export
- plotms multi-panel plots for data and calibration files
- plotms can now plot multiple files, including overplotting in the same panel
- plotms can now write hardcopies of multi-page plots
- flagdata: clipping of values based on WEIGHT and WEIGHT_SPECTRUM
- importasdm with the 'lazy' option will now create an MS which is numerically identical to an MS imported with lazy=False. This means the both the row order and the values of all columns will be the same. It can also be used with all the allowed values of the option wvr-corrected-data.
- formal introduction of UNDEFINED velocity frame
- WEIGHT_SPECTRUM plotting in plotms
- ability to fill/handle data using ephemeris to follow source as single target field
- data selection in fluxscale
- syspower is now associated with scan/field to allow more flexible selection
- setting of polarization fraction and angle in setjy
- higher spectral oder parameters for component lists
- more robust spectral index calculation in fluxscale
- new mode to create a caltable for ionospheric corrections
- wvrgcal: Several improvements concerning the handling of flagged data and NaN solutions. New parameters "wvrspw" and "spw" to control which WVR data is used and for which spectral windows solutions are written into the caltable.
- Data and Image Manipulation
- Graphical plotting of data for the feather task to combine low and high resolution images. The new casafeather standalone GUI can plot the data as slices or radially averaged and allows scatter plots of the two images in uv-space to determine the relative scaling.
- imsmooth can smooth to a common beam if the beam size varies as a function of frequency imsmooth can also use arbitrary image as smoothing kernel, in addition to Gaussian and boxcar kernels
- Field selection for MODEL images in ft
- ability to re-shape spws in mstransform
- per spw rest frequencies in cvel
- imregrid automatically transposes axes to template images
- automated sorting of images by their frequency in ia.imageconcat()
- Data analysis
- rotation measure calculation
- more flexible specifications for position velocity cuts
- support for complex-valued images in many image analysis tasks and tools
- new task imrebin for binning of image pixels
- new task specsmooth for 1-dimensinal smoothing of images
- improved error estimates in imfit
- logarithmic display of data pixel values for range selection
- interactive display of the position on the position-velocity diagram and the position on the cut
- loading of partial cubes and saving of images
- Single Dish
- consistent flag handling in single dish tasks (see cookbook for details)
- a new task sdbaseline2 is available for baseline subtraction, creation and application of baseline table.
- sdimaging and sdplot: the telescope position is used in conversions of frequency and direction frame.
- data selection by raster scan row in sdflag and sdplot
- data selection by raster map iteration in sdplot
- for raster-scanned data, rasterutil module is now available to select individual raster rows and raster scans.
- the telescope weights are now calculated according to bandwidth and integration time
- spectral weights in applycal and mstransform
- weights can be restored to their initial values
- the async parameter was removed from all tasks
- bugfix for the internal storage manager that in some cases caused flags to extend to good data
- Experimental tasks
- cvel2 to provide the functionality of cvel based on the mstransform task
- split2 to provide the functionality of split based on the mstransform task
- hanningsmooth2 to provide the functionality of hanningsmooth based on the mstransform task
- tclean refactored clean task
- CASA has a new MPI parallelization framework and is currently testing use cases.