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fcl, getlimb \- find location of center and radius of limb of solar image.SH SYNOPSIS
.B fcl
\fI[-qv] [argument= value ...]\f
.B getlimb
\fI[-qv] [argument= value ...]\f
\fIfcl\fR and \fIgetlimb\fR find the center and radius of the "best fit"to a circular limb
in a solar image. The limb is defined as the location of the maximumgradient near pixels whose values are approximately equal to\fIfrac_thresh\fR times the average value in a central square. Data inright triangles in the corners are ignored. The only distinction betweenthe two programs is in the format of the output.

The \fB\-q\fR option prints out the list of required arguments and their

default or environmental values, then quits. The \fB\-v\fR option sets \fIverbose\fR mode, redirecting history from \fIstdout\fR to \fIstderr\fR.
.NXR ""
.NXR "fcl command" "options"
.NXR "getlimb command" "options"
.IP \fBin=\fIname\fR 20

The dataset name of the input.

.IP \fBfrac_lenside=\fIfloat\fR 20
size of ignored triangles (default 70/1024).
.IP \fBfrac_box=\fIfloat\fR 20
size of central box for determining threshold (default 200/1024). .IP \fBfrac_thresh=\fIfloat\fR 20
threshold multiplier (default 0.3).
.NXR(e) ""
fcl in= /scr24/phil/optest/oct508/lev1/V_mdi/V_mdi.048.fits .br
produces the output:
xc = 132.426, yc = 143.998, radius = 114.626

getlimb in= /scr24/phil/optest/oct508/lev1/V_mdi/V_mdi.048.fits .br
produces the output:

RMAJOR=114.626 X0=132.426 Y0=143.998


There is no good reason for having two separate programs simply to

provide output strings in different formats. A flag would suffice, if the formats were essential.

Only works for square data arrays. The threshold and corner zeroing

parameters should not have to be supplied.

Lyle Bacon, based on a routine by Cliff Toner as inherited through

Robert Ronan

1994-02-14 SOI Version 0.8
.#$Id: fcl.1,v 1.1 1994/02/17 00:10:10 CM Exp $ .#$Source: /home/soi/CM/man/man1/RCS/fcl.1,v $
.#$Author: CM $

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