./guide
getfs.pro

Last modification date:

Thu Jun 2 23:56:08 2005

getfs

procedure getfs, scan, [ifnum=integer], [intnum=integer], [plnum=integer], [fdnum=integer], [tau=float], [ap_eff=float], [units=string], [nofold=flag], [noweight=flag]

This procedure retrieves and calibrates a frequency switched scan. Frequency switched data obtained with other procedure names will be rejected by this procedure. This code should be used as a template for the user who may wish to develop more sophisticated calibration schemes or reduce frequency switched data from other types of procedures. This routine produces a spectrum calibrated in Ta (K) (other recognized units are 'Ta*' and 'Jy').

The only required parameter is the scan number. Arguments to identify the IF number, polarization number, and feed number are optional. A zenith opacity can be entered. The program calculates Tsys based on the Tcal values, and cal_on/cal_off phases.

All averaging is done using dcaccum and accumave. This means that integrations are weighted using the default weight given in dcaccum. To turn off this weighting so that all integrations have equal weight in the average, use the /noweight flag.

There must be 4 switching states and the SWITCH_STATE value must be 'FSWITCH'.

Examples

    getfs,76
    accum
    getfs,77
    accum
    ave
    show
 

a nofold example, show each half and then fold

    getfs,76,/nofold
    oshow,1
    fold
 

Uses

dcfold

Version

$Id: getfs.pro,v 1.21 2005/05/30 04:03:43 bgarwood Exp $

Parameters
scan in, required integer	scan number

Keywords
ifnum in, optional integer	IF number
intnum in, optional integer	integration number
plnum in, optional integer	polarization index (0 or 1)
fdnum in, optional integer	feed number (default 0)
tau in, optional float	tau at zenith
ap_eff in, optional float	aperture efficiency
units in, optional string	takes the value 'Jy', 'Ta', or 'Ta*'
nofold in, optional flag	if set, does no folding. When this is set, data container 0 contains the results of (sig-ref)/ref while data container 1 contains the results of (ref-sig)/sig, calibrated independently and averaged over all integrations. Only data container 0 will be shown.
noweight in, optional flag	if set, the default weighting is turned off and all integrations are averaged with the same weight (1.0).