CALIBRATE: ONEDSPEC vs LONGSLIT

Frank Valdes wrote on Jul 15, 1998

Q:  I'm using calibration in onedspec.  

I want to calibrate some files with the sensitivity function obtained
from another night.  I called these files sens....  So I copied the
sens files to the directory I was working on.

Here are my parameters in calibrate:


PACKAGE = onedspec
   TASK = calibrate

input   =               w6023r  Input spectra to calibrate
output  =             cal6023r  Output calibrated spectra
(extinct=                  yes) Apply extinction correction?
(flux   =                  yes) Apply flux calibration?
(extinct= onedstds$ssoextinct.dat) Extinction file
(observa=                  sso) Observatory of observation
(ignorea=                   no) Ignore aperture numbers in flux calibration?
(sensiti=            sens4033r) Image root name for sensitivity spectra
(fnu    =                   no) Create spectra having units of FNU?
airmass =                 1.36  Airmass
exptime =                3600.  Exposure time (seconds)
(flpar  =                   no) flush pfile on assign?
(mode   =                   ql)



I'm getting an error saying:

ERROR: Cannot open image (sens4033r.0001)

I can splot sens4033r and look at the header.  So I'm not sure why it wants
to open sens4033r.0001.  I've copied other sens files from elsewhere before
and it has worked. 

I eventually found that calibrate in the longslit package worked.  So I
guess I should have been using this task instead.


A:  Actually CALIBRATE is the same task in ONEDSPEC and LONGSLIT but with
slightly different default parameters.  Your problem was in the setting
for "ignoreaps".  If ignoreaps=yes then it will apply the specified 1D
sensitivity spectrum to all apertures (in multispec data) and all lines
and columns in long slit 2D data.  This is what you needed and this is
the default in the LONGSLIT package.  If ignoreaps=no, the default in
the ONEDSPEC package, then this means that there is a different
sensitivity function for each aperture in the data.  Note that long
slit images are considered as a collection of apertures with each
line/column being an aperture with aperture number given by the line or
column.  The specified name is then a root name and it appends the
aperture number to form the name for the particular aperture.  For
example for aperture 1 (line/column 1 for your data) it wants
sens4033r + .0001 = sens4033r.0001.

---

Last post on Jul 15, 1998