question on IRAF noao > onedspec > dispcor
Guest wrote on Aug 07, 2006
Hi,
I am an user on IRAF (2.12.2) and I have a question when doing the data
reduction on my 1D spectral data, by using the task dispcor uder the package:
noao > onedspec.
I have a set of scientific and calibrating (lamp) data, and both of them
extracted and identified. Then I processed to the task dispcor aiming to apply
the calibrated wavelength database to the scientific data. After I typed in
something like
hedit vegartds.ms.imh refspec hgrtds.ms.imh add+ ver-
dispcor vegartds.ms.imh vegawcal linearize=no
then a warning ¡§resampling using current coordinate system¡¨ printed.
When I splot vegawcal.imh, the x-axis of the graph is in the unit of pixel,
rather than wavelength.
I would like to ask is ¡§resampling¡¨ means something is missing or wrong? How
can I make a wavelength calibrated graph (i.e. x-axis in wavelength)? Please
notice that I had rotated the data in 90 degrees before inputting them in IRAF.
Thanks. Looking for the replay.
C.W. SO
HK research student
Post generated using Mail2Forum (http://www.mail2forum.com)
I am an user on IRAF (2.12.2) and I have a question when doing the data
reduction on my 1D spectral data, by using the task dispcor uder the package:
noao > onedspec.
I have a set of scientific and calibrating (lamp) data, and both of them
extracted and identified. Then I processed to the task dispcor aiming to apply
the calibrated wavelength database to the scientific data. After I typed in
something like
hedit vegartds.ms.imh refspec hgrtds.ms.imh add+ ver-
dispcor vegartds.ms.imh vegawcal linearize=no
then a warning ¡§resampling using current coordinate system¡¨ printed.
When I splot vegawcal.imh, the x-axis of the graph is in the unit of pixel,
rather than wavelength.
I would like to ask is ¡§resampling¡¨ means something is missing or wrong? How
can I make a wavelength calibrated graph (i.e. x-axis in wavelength)? Please
notice that I had rotated the data in 90 degrees before inputting them in IRAF.
Thanks. Looking for the replay.
C.W. SO
HK research student
Post generated using Mail2Forum (http://www.mail2forum.com)
Francisco Valdes wrote on Aug 07, 2006
Hello,
The message you report occurs when DISPCOR believes the data has already been dispersion calibrated or no calibration information is given. It may also occur because the reference spectrum must include information that it has been used by IDENTIFY. In particular the reference spectrum, hgrtds.ms in your case, should also have a refspec keyword whose value is itself. The problem could also be that the keyword is refspec1 and not refspec.
Please consult the help page for DISPCOR further and possible take a look at REFSPEC. If you still have problems post a header listing for vegartds.ms and hgrtds.ms.
Yours,
Frank Valdes
The message you report occurs when DISPCOR believes the data has already been dispersion calibrated or no calibration information is given. It may also occur because the reference spectrum must include information that it has been used by IDENTIFY. In particular the reference spectrum, hgrtds.ms in your case, should also have a refspec keyword whose value is itself. The problem could also be that the keyword is refspec1 and not refspec.
Please consult the help page for DISPCOR further and possible take a look at REFSPEC. If you still have problems post a header listing for vegartds.ms and hgrtds.ms.
Yours,
Frank Valdes
Last post on Aug 07, 2006