SETBOLWT - Calculate or set bolometer weights

Description:

This routine sets the bolometer weights. It can do this in two ways:

1. Calculate the statistics for each bolometer then generate the weights relative to the central pixel. Should not be used when a strong source is present. The weights are calculated by using KAPPA stats to calculate the standard deviation of each bolometer in turn. The weight is defined as the relative variance between this bolometer and the reference bolometer.

2. Read the weights from a text file using the -wtfile option.

Writes to the BOLWT extension. This extension is then read by rebin.

Multiple files can be referenced to the first file by specifying multiple files on the command line or by using a rebin-style input file and the -filelist option. In conjunction with the -wtfile option all input files are given the same weights.

Usage:

setbolwt [-h] [-wtfile=] [-filelist=] filenames...

Parameters:

$-$h

Return a usage message.

$-$wtfile=file

An ASCII text file containing the weights, one weight per line corresponding to the order of bolometers stored in the file.

$-$filelist=file

An ASCII text file containing a list of files to be processed. There must be one file per line and it must be in a form acceptable to rebin (ie comments can be included).

filenames

List of filenames to be processed. Wild cards can be used. eg $*$_lon_ext.sdf.

Examples:

setbolwt

The user will be prompted for a list of input NDFs. The weights will be calculated by setbolwt.

setbolwt -wtfile=weights.dat file1

Set the weights in file1.sdf from the list contained in weights.dat

setbolwt file1 file2 file3 file4

Calculate the weights of each bolometer in all four files relative to the central pixel in file1.sdf.

setbolwt -wtfile=wt.dat -filelist=rebin.inp

Set the weights of the files listed in rebin.inp to those stored in wt.dat (same weights for each file).

Notes:

• Input files must have been extinction corrected so that only one sub-instrument is present per file.

• When multiple files are used bolometers are compared to the central bolometer of the first file.

• If source signal is present in any bolometer at a level significantly above the noise, the automatic weighting will be skewed (in fact the bolometer with the source signal will be down-weighted relative to all the others since the standard deviation on the bolometer will be much higher.). The weights must be set via an external file in this case.

Related Applications

SURF: rebin
KAPPA: stats