Forum der Vereinigung der Sternfreunde

I have developed some IRAF scripts that reduce my echelle spectra.

The script has several places where it needs the date and object name. I would like to be able to set these in one place and use a variable to pass the value.

I have tried for example

char Target = "object"

scopy ABC.fit Target.fit

but get the file Target.fit rather than object.fit

Is there a way to do this?

Thanks in advance for any advice.

Regards Andrew

Hi Andrew,
do you use CL or pyraf?
Christian

Hello Andrew,
I didn't realize that the answer to my question was already mentioned in the subject. You will find the answer here:
http://stsdas.stsci.edu/documents/SUG/U ... HEADING161
Cheers
Christian

Thanks I will look at the document. Regards Andrew

Hi Andrew,
perhaps I should draw your attention on the (==>)-operator. E. g. given some images im1.fit, im2.fit, ...,im10.fit plus dark.fit you can with the command
files im*.fit > list
generate a file with all the names of images. With
imarith @list - dark.fit d//@list
the dark will be subtracted from all images. The resulting images are named dim1.fit, ..., dim10.fit
This technique replaces the need for scripts in many cases.
The power of CL is very limited. E. g. there are only string variables called s1, s2, s3. For many cases this may be sufficient. When you use the above mentioned (==>)-operator it no Problem to write a script for the normal reduction procedure. Pyraf is a more powerful choice. It seems to be quite popular. However I have no experience with Pyraf.
Regards
Christian

Thanks Christian, I have use the (==>) and * in my script and with the other advice you gave now have just what I need. I can input the star name and observation date and do all the processing without further intervention.

Thanks Andrew

Hi Andrew,
today I used an Iraf script for the first time. I had 60 1D spectra and for each spectrum an individual calibration file. The problem was to assign each header of the object spectra the correct calibration files. Firstly I created a file
spec1 cal1
spec2 cal2
.... .....
spec60 cal60

called comb.dat. My script was

list = "comb.dat"
while (fscan( list, s1, s2) != EOF) hedit(s1, "REFSPEC1", s, add+, ver-, show)
I saw no other solution for this problem.
Cheers
Christian

I can see that will be a help in the future, Christian

Thanks Andrew

Hi Andrew

I am interested and Klaus too to reduce echelle spectra with IRAF too. Do you think, I could use your Script to do so? If yes, could you give me your script?

Cheers
Berthold

Hi Berthold, I am sorry but it is not that simple.

You have to set up IRAF to match your spectrograph first.

I did the basic image processing using elementary tasks as described here: http://www.twilightlandscapes.com/IRAFtutorial/

I then followed the setting up of the extraction and wavelength calibration (missing out flat fielding and scattered light) from here:
http://citeseerx.ist.psu.edu/viewdoc/do ... 1&type=pdf

I am still very much a novice at this and am reluctant to share my primitive script as it is as it is a work in progress.

There are turorials on the IRAF site and I tried these as well. The main stumbling block is learning the way to use the interactive windows as they are non standard and differ in different tasks. I sent Klaus a list of IRAF references.

I did do a note on getting IRAF installed on Windows (attached). I will do an overview of the steps I use and post later.

I hope this helps.

Regards Andrew

Here are the other links I found helpful.


http://iraf.noao.edu/docs/spectra.html

http://iraf.noao.edu/tutorials/tutorials.html

http://iraf.noao.edu/

http://stsdas.stsci.edu/gethelp/HelpSys.html

Regards Andrew