Measuring Profile Characteristics of HI spectra in IDL . Gomathi Thai, with the help of Tapasi Ghosh, has rewritten the old analyz (and uni-pops) routines for measuring the profile characteristics of HI data into IDL. ... First is to average the two polarizations, then apply smoothing (or not), fit and subtract a baseline, and finally calculate the velocity, velocity width, area under the curve using the five options that the MSR program in ANALYZ is currently using. ...

... 2.3 Data acquisition Spectra generated by the Multibeam correlator contain the usual structure seen in spectra from other H i instruments: a bandpass spectrum which is the sum of the sky , ground and receiver temperatures multiplied by the product of the filters in the receiver chain; superimposed on this is a noise ... Note also that sources extended much beyond ,40 arcmin can be imaged poorly in HIPASS images because of the bandpass sidelobe effect described in Section 3.3. ...