ASAP - ATNF Spectral Analysis Package

The ATNF Spectral Analysis Package is a new software package that has been developed within the ATNF, to reduce single-dish, single-pointing spectral line observations. ASAP is now used for single-dish data from ATNF instruments and should be able to read data from any telescope if the data can be written in the "sdfits" format.

ASAP has been developed in c++ using a python front-end for the user interface. The c++ code makes extensive used of the casa libraries (the package formerly known as aips++).

Standard spectral line calibration and analysis is supported (baseline subtraction, smoothing, statistics, Gaussian fitting, time averaging etc.) as well as a number of advanced functions such as to automatically pair reference and source spectra to form quotient spectra, automatically fit a low order polynomial to line free channels in a spectrum, correct for Doppler shift between scans when averaging and use of frequency switching. Polarimetry support suitable for observing with linear feeds at Parkes is available; this includes various calibration corrections and conversion to Stokes or circular polarisations.

ASAP v2 has recently been released. The main change was a major re-design to support varying numbers of spectral channels per intermediate frequency (IF) or per beam. In particular, ASAP will be used for data from the new wideband MOPS spectrometer at Mopra, as it can process many simultaneous IFs and beams in parallel. For "well behaved" data it is possible to load, calibrate and baseline subtract a multi-beam, multi-IF data set with a small number of commands. Flexible data selection is included to select based on a variety of values (beam, IF, polarisation, source name etc). Power users can also select data on properties such as the system temperature.

Currently only binary versions are available for Debian Linux and OSX. A binary version for Fedora Linux should be available shortly. Other flavours of Linux may work with these binaries - contact the development team for help. ASAP is easy to compile from source, however it depends on having a full version of the casa development libraries installed. The team is also trying to simplify the process of obtaining only the relevant casa libraries.

For more information see www.atnf.csiro.au/computing/software/asap.

Chris Phillips and Malte Marquarding
(Chris.Phillips@csiro.au, Malte.Marquarding@csiro.au)