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powercor noao.imred.iids/noao.imred.irs



powercor -- Apply power law correction to mountain reduced spectra


powercor input records


The root file name of the input spectra.
The range of spectra. The names of the spectra will be formed by appending the range elements to the input root name.
This is the root file name for the corrected spectra.
start_rec = 1
The starting record number to be appended to the root name of the created spectra.
power = )iids.power
The power law coefficient.


A power law correction to the IIDS count rates is applied to the input spectra. The mountain reduction software applies a coincidence correction to the observed IIDS count rates but does not correct for a nonlinear effect in the image tube chain. This second correction takes the form of a power law

C(out) = C(in) ** power

where C(in) is the input, coincidence corrected, count rate and C(out) is the corrected count rate. The power is a parameter of the task which defaults to the iids package parameter set to the appropriate value for the IIDS. The exposure time, in seconds, is a required image header parameter (keyword = EXPOSURE) used to convert the total counts to count rates.

Note that if the original raw spectra are being reduced then the either coincor or powercor may be used to apply both the coincidence correction and the power law correction at the same time. In other words, the tasks apply the coincidence correction if the coincidence flag (CO-FLAG) is -1 (uncorrected) and the power law correction alone if the flag is zero (coincidence corrected only). The flag is 1 when both the coincidence and nonlinear correction have been applied.

This task is a script calling coincor with ccmode = "iids".


The following example corrects a series of IIDS spectra:

cl> powercor nite1 1-250 output=nite1cc start_rec=1



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