GETSPEC

Name

getspec

Purpose

Extract a point source spectrum from OSIRIS XD data.

Description

Calling Sequence

getspec,calib,root,i1,i2,spec,all,
RAW=raw,NONEG=noneg,AUTO=auto,MASK=mask

Inputs

calib- Anonymous structure containing all pertinent calibration
information. This structure is usually loaded beforehand using
the routine, "ldcalir"
root - string containing the root of the file name (with leading path
if desired). DO NOT include the . between the root and suffix.
i1 - Frame id (integer) of first image.
i2 - Frame id (integer) of second image.

Optional Input Parameters

Keyword Input Parameters

AUTO - Flag, if true, enables automatic aperture location for extracting
the spectra. The image is collapsed into a single column. Any
pixel more than 3 sigma from the background is flagged for
extraction. Default is to require clicking on the image displayed
in window 0. Three rows centered on the clicked location are
extracted for the spetrum. /AUTO is the preferred option.
APLOC- Override to specify the positive object location. Overrides AUTO.
APSIZE-Override to force the size of the extraction aperture. The
will extend from the location (auto or APLOC) + and - by APSIZE.
Thus the total aperture is 2*APSIZE+1 rows.
NONEG - Flag, if true, inhibits using the "negative" spectrum in the
background image (i2). Default is to extact the negative
spectrum, negate it, and add to the positive spectrum.
RAW - Flag, if true will inhibit the column-wise background subtraction.
The default is to fit the background in each column (along the
slit) and subtract the fitted background. Use a linear function
for the background.
MASK - Indicies in strip image. These pixels will be replaced by the
average of their nearest neighbors in the x direction.
SAVE - Flag, if true, final spectrum will be saved to a file. The output
file name is root+'s'+suffix. Thus 950911.003 would be saved to
the file 950911s.003
PATH - optional string that points to the directory containing the data.
This information is not used if the root already begins with '/'.
If root is not an absolute pathname, then PATH is prepended to
root for READ operations. This path is not used for saving.
This allows reading from one directory (possible a read only area)
and then saving to the current directory.
CLEAN - Flag, if set, calls clnspec to allow removing bad points before
saving spectrum.

Outputs

spec - 1-D spectrum extracted from spectral image.
all - i1-i2 after XD spectra extracted to strip image. (see getpair)

Keyword Output Parameters

Common Blocks

Side Effects

Restrictions

Specifically written for OSIRIS cross-dispersed spectral data. MASK
does not work particularly well.

Procedure

Modification History

95/03/24, Written by Marc W. Buie, Lowell Observatory
95/06/21, MWB, modified aperture algorithm.
95/09/14, MWB, added calib structure pass through, added SAVE flag, added
PATH keyword, added CLEAN flag.
95/09/18, MWB, improved auto-aperture locating algorithm
95/09/21, MWB, added APLOC and APSIZE keywords