msutils

Tools for manipulating CASA Measurement Sets (MS), for radio-astronomy pipelines.

Features

• Summarise an MS — fields, spectral windows, antennas, scans, correlations — to a dict / JSON.
• Add, copy, and sum/subtract visibility columns, chunked by spectral window.
• Add Gaussian noise to a column (from a stddev, or computed from an SEFD).
• Verify / fix antenna Y-position sign conventions.
• Flag statistics per antenna / scan / field / correlation, with a matplotlib summary plot (flagstats extra).
• Per-channel visibility weight estimation from an SEFD profile (plots extra).
• A msutils command-line tool wrapping the above.

Install

Requires Python >= 3.8. python-casacore is pulled in automatically (its wheels bundle the casacore libraries).

pip install msutils                 # core column operations + CLI
pip install "msutils[flagstats]"    # + flag statistics & plots (dask-ms, matplotlib)
pip install "msutils[plots]"        # + weight estimation (matplotlib, scipy)
pip install "msutils[all]"          # everything

Python API

The core operations are exposed directly on the package:

import msutils

# Metadata summary (returns a JSON-serialisable dict)
info = msutils.summary("obs.ms")

# Column operations
msutils.addcol("obs.ms", "MODEL_DATA", clone="DATA")
msutils.copycol("obs.ms", "DATA", "CORRECTED_DATA")
msutils.sumcols("obs.ms", cols=["DATA", "MODEL_DATA"], outcol="CORRECTED_DATA")

# Add noise (computed from an SEFD, or a fixed stddev)
msutils.addnoise("obs.ms", column="MODEL_DATA", sefd=551)

Flag statistics and weight estimation live in optional submodules:

from msutils import flagstats                 # needs msutils[flagstats]
flagstats.plot_statistics("obs.ms", plotfile="flags.png", outfile="flags.json")

from msutils.weights import MSNoise           # needs msutils[plots]

Command line

msutils summary  obs.ms --json summary.json
msutils addcol   obs.ms MODEL_DATA --clone DATA
msutils copycol  obs.ms DATA CORRECTED_DATA
msutils sumcols  obs.ms DATA MODEL_DATA --out CORRECTED_DATA
msutils addnoise obs.ms --column MODEL_DATA --sefd 551
msutils flagstats obs.ms --plot flags.png --json flags.json   # needs msutils[flagstats]

Run msutils --help or msutils <command> --help for all options.

Migrating from 1.x / MSUtils

• The import package is now lowercase msutils (the capitalised MSUtils still works, with a deprecation warning).
• The core functions are on the package root — use msutils.summary(...) instead of from msutils import msutils.
• Modules renamed: flag_stats → flagstats, ClassESW → weights (old names still importable, deprecated).
• imp_plotter (gain/calibration-table plotting) was removed — use ragavi (ragavi-gains) instead.
• The defunct prep() and its external-binary dependencies were removed.

License

GNU GPL v2 or later. See LICENSE.