Personal tools
You are here: Home / COSMOS / badorders

badorders

Back to Programs

badorders

badorders constructs a bad pixel file containing the positions of spectral features from other spectral orders that may overlay the desired spectrum.


USAGEbadorders -o observset [-i input_badpix_file] -f output_badpix_file
INPUT
observset is the root name of a set of observation definition file, one per spectral order, which describes the observing setup used for the frame
input_badpix_file.badpix is the name of a non-standard bad pixel
file to which the new bad pixel groups will be added.
OUTPUToutput_badpix_file.badpix is the new bad pixel file created
PARAMETERS
borderwidth of border added to each spectral region
linefilefile with list of lines to be blocked in non-zero order spectra
orderslist of spectral orders to be blocked (e.g. 023 for zero, 2nd and 3rd orders)
hwidthhalf width, in angstroms, of each non-zero order spectral feature
shuffleshuffle distance, in pixels, for nod&shuffle; data; otherwise 0
lambda0minimum of spectral range of zero order spectrum
lambda1maximum of spectral range of zero order spectrum


Details:

badorders calculates the location and extent of spectral features from other orders of a spectrum which need to be blocked during the spectral reduction process. It creates a bad pixel file which can be used as input to the programs Sflats and subsky, in place of the standard bad pixel file which exists for each dewar. If no other input bad pixel file is specified, the standard bad pixel file for the dewar in use is used as a starting point, to which new bad pixel groups are added for each spectral feature to be blocked. Note that the binning of the output bad pixel file will be the same as that of the input bad pixel file, so that if a non-standard input bad pixel files is used with, e.g. 2 x 2 binning, the output bad pixel file will also have 2 x 2 binning.


badorders uses the information in the observation definition files to calculate the location and extent of each spectral feature. For zero order, the blocked region extends between the wavelengths specified by lambda0 and lambda1. For higher orders, the blocked region is located at the wavelength of each line specified in linefile, and has a width in wavelength of +/- hwidth angstroms. An appropriate observation definition file must be created for each order, and will have the name observset_n.obsdef, where n is the order. Each observation definition file must specify the order, and will usually specify an individual dewar offset file appropriate for that order image, since there will probably be small offsets between the true positions of the features in each order, and those predicted by the optical model. Consult the COSMOS Cookbook for hints about constructing these files.


Back to Programs