Basic Information on zeeeta

Task: zeeeta
Purpose: Compute Zeeman parameter eta
Categories: profile analysis

        ZEEETA is a MIRIAD task to compute the Zeeman signal-to-noise
        parameter eta;
 
        eta  =  (dI/dnu)_rms / sigma
             =  sqrt[SUM (dI/dnu)**2 / N] / sigma
 
        where sigma is the standard deviation of the I or V image, and N
        is the number of channels in the spectrum.
 

Key: in
        The input Stokes I image in vxy order.  No default.

Key: out
        The output eta image, if blc,trc is not specified.

Key: sigma
        r.m.s. noise of signal free I spectrum.

Key: chan
        The channel range.  Default is all channels.

Key: blc
        Specify the blc of the spatial window in pixels.  If unset, the
        whole image is done, with no spatial summing, and an output eta
        image made.  If blc and trc are set, then eta is computed for
        this window, and the results output to the terminal.

Key: trc
        Specify the trc of the spatial window in pixels

Key: der
        1 or 2 for one or two sided derivative.  If you would like to
        see a plot of the last derivative spectrum, include a 'p' as
        well, e.g. 2p or 1p.

Key: aveop
        'a' to average spectra before computing eta.  Only if blc,trc
        set.
 
Revision: 1.6, 2013/08/30 01:49:21 UTC