WSClean version 3.1

Released 2022-04-01

New/changed dependencies:

Summary: Facet-based imaging is significantly improved, and now supports applying per-facet solutions (from H5Parm files) and beam corrections (from EveryBeam). Stokes-I-only imaging with IDG imaging is now significantly faster. WSClean 3.1 also adds experimental support for GMRT primary beam correction.

Major & visible changes

  • Support time-direction baseline-dependently averaged data from DP3.

  • Reduce disk-access during IDG Stokes I imaging by not storing XY/YX to disk, and enable the faster IDG Stokes I mode when possible.

  • Automatically use the primary beam corrected image (...-pb.fits) file when predicting with beam correction.

  • Cache average beam to disk in IDG mode to reduce memory usage.

  • Add support for the GMRT beam (scientific validation still in progress).

  • Add a beam-normalisation-mode option to control EveryBeam’s normalisation mode.

  • Support multiple h5 files in facetting mode.

  • Introduce -pb-grid-size and deprecate -pb-undersampling.

Bug fixes

  • Report error when user asks for incorrect channel selection.

  • Fix certain selection parameters that no longer worked in reorder mode (e.g. even/odd timestep selection).

  • Correctly normalize reported flux levels for squared channels.

  • Fix a crash with the -reuse-dirty option in certain modes.

  • Fix segmentation fault when using -reuse-psf with IDG.

  • Fix masked parallel deconvolution.

  • Fix beam + H5 solution application in facetting mode.

  • Fix possible -facet-regions mismatch with H5Parms.

  • Support differential lofar beam in facet-based imaging.

  • Support scalar gain corrections in facet-based imaging.

  • Do not apply beam or solutions to PSF in facet-based imaging.

  • Fix unset threadcount value in imageweights class.

  • Fix IUWT. Because of code clean-ups in Nov 2020, the IUWT deconvolution option was no longer producing correct results.

  • Fix channel selection issue for non-uniform multi-SPW sets (#79).

  • Fix channel selection issue for multi-SPW set with no-mf-weighting (#105).

  • Fix rare crash caused by uninitialized array.

  • Fix compilation on hurd-i386.

Other significant code changes

  • WSClean now requires a compiler that supports C++17.

  • Add support for gcc versions 11 and 12.

  • Lots of refactoring.

  • Preparations to split off deconvolution code as a separate reusable module.

  • Several documentation improvements / updates.

  • Better support and error reporting for missing git submodules.

  • Many new unit and system tests.