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Basic Structure

ASAP data handling works on objects called scantables. A scantable holds your data, and also provides functions to operate upon it.

The building block of a scantable is an integration, which is a single row of a scantable. Each row contains spectra for each beam, IF and polarisation. For example Parkes multibeam data would contain many beams, one IF and 2-4 polarisations, while the new Mopra 8-GHz filterbank will eventually produce one beam, many IFs, and 2-4 polarisations.

A collection of sequential integrations (rows) for one source is termed a scan (and each scan has a unique numeric identifier, the ScanID). A scantable is then a collection of one or more scans. If you have scan-averaged your data in time, then each scan would hold just one (averaged) integration.

Many of the functions which work on scantables can either return a new scantable with modified data or change the scantable insitu. Which method is used depends on the users preference. The default can be changed via the .asaprc resource file.