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fradius stsdas.hst_calib.foc.foccs


NAME · USAGE · DESCRIPTION · PARAMETERS · EXAMPLES · BUGS · REFERENCES
SEE_ALSO

NAME

fradius -- Compute the radius of a PSF.

USAGE

fradius input output

DESCRIPTION

This task computes the radius of the point spread function (PSF) as an indication of how far each image is out of focus. This task computes the radius directly, while the faradius task computes the radius of the autocorrelation. A line of output is written for each row of boxes (read from the input file from the fextract task). For each box along a row, the position of the PSF is determined by taking the average of X and Y, weighted by pixel value. The sums of values and values multiplied by distance from this position are then accumulated, combining values for different boxes along the row. The radius is the sum of values multiplied by distance divided by the sum of values.

PARAMETERS

input = "" [string]
Name of input image. The output from the fextract task provides the input to this routine.
output = "" [string]
Name of output text file which will contain two values per row: the refoc mirror position (read from the input header) and the characteristic radius.

EXAMPLES

BUGS

REFERENCES

This task was written by Phil Hodge.

SEE ALSO

faradius, fsquares


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