msmetadata (msmd) is a powerful tool that allows users to directly access MeasurementSets. It is not generally used in the data reduction and is recommended for advanced users that want to manipulate MeasurementSet tables. The default global tool is named  msmd.

Summary of Tool Use

The simplest and most common way to attach an msmd tool to a MeasurementSet is to use the method which requires that you specify the name of the MeasurementSet table. When one has finished with the tool, the msmd.close() or msmd.done() method should be called to free up resources that the tool uses when it is attached to an MeasurementSet (MS). msmd has several functions, as for example: get the list of spectral windows, antenna numbers, band widths, field names, intents, numer of channels for a given spectral window, phase centers, scan numbers, observing time for a specific scan, and many other functions listed in Methods.

NOTE: Any modifications to an MS while an associated msmd tool is open will not be reflected in the msmd tool. You must close and reopen the tool if you want to capture changes made to metadata of an MS if such a change occurs.