./toolbox
estboxres.pro

Last modification date:

Wed Sep 28 13:27:11 2016

estboxres

function estboxres(width, oldres)

Estimate the new frequency_resolution after boxcar smoothing something with a known old frequency_resolution.

This estimates the new frequency_resolution by assuming that the frequeny_resolution is the FWHM of a gaussian response function and that the ratio of the widths is equal to the inverse ratio of the heights of the response functions before and after the smoothing. Since a boxcar function isn't a Gaussian, this will be inaccurate to some degree. The initial response function may also not be Gaussian. Tests against a full convolution as well as tests involving noise from real GBT data indicate that this estimate is accurate to within a few percent.

The boxcar procedure uses this function to adjust the frequency_resolution of the data container.

Returns

the frequency resolution in channels after boxcar smoothing to the given width.

Examples

   ; what would the new resolution be of the PDC after boxcar
   ; smoothing with a width of 5 channels.
   print,

   esthanres(5,!g.s[0].frequency_resolution/abs(!g.s[0].frequency_interval))
 

Uses

gaussrespfn

Version

$Id$

Parameters
width in, required integer	The width of the boxcar.
oldres in, required float	The frequency_resolution in channels before boxcar smoothing.