National Radio
Astronomy Observatory

Chapter 8
Single Dish Data Processing

NOTE: The single-dish analysis package within CASA is included in the release for the use of the ALMA computing and commissioning groups. However, it is fully accessible for general users.

For single-dish spectral calibration and analysis, CASA uses the ATNF Spectral Analysis Package (ASAP). ASAP is imported as the sd tool at the start-up of CASA.

It forms the basis for a series of tasks (the “SDtasks”) that encapsulates the functionality within the standard CASA task framework. ASAP was developed to support the Australian telescopes such as Mopra, Parkes, and Tidbinbilla, and we have adapted it for use within CASA for GBT (see the note below for limitation of GBT SDFITS handling) and eventually ALMA [Note: Some support for the ALMA is now available]. For R3.4 or later, the ASAP version included in CASA was updated to 4.0 (which is the latest official release of ASAP as of Mar. 2012). In ASAP 4.0, data format was also updated from 3.0 to 4.0. Note that data in version 3.0 format are automatically updated to version 4.0 format and replaced.

For details on ASAP – including the User Guide, Reference Manual, and tutorial – see the ASAP home page at ATNF:

• http://svn.atnf.csiro.au/trac/asap/ .

The ASAP tools are prefaced with sd. within CASA, e.g., the ASAP tool scantable becomes sd.scantable. See § 8.3 for more information on the tools.

All of the ASAP functionality is available within the CASA installation. Since we extended ASAP, there are certain functionalities that are available only in the CASA version of ASAP. In the following subsections, we outline how to access ASAP from within CASA and the data flow for standard use cases.

If you run into trouble, be sure to check the list of known issues and features of ASAP and the SDtasks presented in § 8.5 first.

R3.4 New Features
The single dish package (ASAP) is now loaded at the start-up of CASA. It is not necessary to load ASAP explicitly by invoking asap_init anymore.

More information about CASA may be found at the CASA web page

Copyright © 2010 Associated Universities Inc., Washington, D.C.

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