The DEBRIS tutorial

This tutorial takes you step by step through a mini-analysis of a set of data using the DEBRIS package. To do so you will need the data to be analysed and of course the software. For information on how to get both, contact me.

You have both the data and the software (already installed)? Then login to IRAF, load the DEBRIS package and let's go.

From now on I will assume that the DEBRIS package was loaded so that the IRAF prompt is now "de>".

First of all, all images must be converted from fits format to IRAF format using the task RFITS. cd to the directory where your data is stored, type

de> eparam rfits

and make it look like this.
Type :go to run RFITS.
If you want, you can now delete all the fits files or store them somewhere else for future use.

This image (demo3) is an example of the data we are analysing. In fact, it is exactly the same as data0022 (except for the circle of course). It has a point source artificially added to it at the indicated position. In the rest of the data set this point source moves in both x- and y-directions at a speed of 2 pixels/image.

This image (demo4) shows what DEBMV made out of the data set represented by demo3. We will now attempt to remake this image from the given data set. Go to your data directory, type

de> eparam debmv

and make it look like this.
Again, type :go to run DEBMV.
Don't be irritated by a warning about image orientation. Read the help documentation to see what this is about. Allow DEBMV to run a few minutes before suspecting that something is wrong. The result should be an image called demo0001.imh and two logfiles, logdemo and logdemo0001. They should look like this: logdemo, logdemo0001. The image demo0001.imh should be the same as demo4.

We will now search demo0001 for any objects using DEBFIND:

de> eparam debfind

The result will be a file called demo0001.coo.1. It should be the same as this. You will notice that besides the one detection we expected, this coordinate file contains a number of unwanted detections all of which are very faint though. To discard these (and to search the thousands of other coordinate files that would need processing were this a detailed analysis of the data) we will now run DEBREPORT:

de> eparam debreport

The resultant output should be as shown here.

I hope everything went as it should. At this time, I am not aware of any bugs in the software except for bugs in older versions of the task IMCOMBINE which is of central importance to the DEBRIS package. I am of course more than willing to help with any problems or clarify any of the above. Just send me a mail and I'll do what I can to help.

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