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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.



Malte Marquarding 2005-11-30