Retrieve the Data

All of the images that we take with the 16-inch telescope will be stored on the astronomy lab computers in a directory /moore. Look for a subdirectory with the date of the observations. This directory contains the original ``fits'' image files, and a file of notes that describe each image.

These systems run Linux and have a ``Gnome'' user interface, so there will be a familiar looking graphical screen with icons available. Most work with Linux or Unix is done from the command line, so begin by opening a ``Console'' into which you can type commands. The icon for a console is the image of a computer screen on the top bar. It may have a large X on it as well. Double click this icon and a console window should appear. If you want more than one window, just do this again. You also have four ``workspaces'' available represented by the small images at the bottom right. Click on one these if you need an uncluttered screen. Linux is multi-tasking and you may do several things at once.

Here are a few help commands that can be typed into the console screen that you may need:

cd change directory

mkdir create a directory

ls list files in the directory

ds9 display images

fits_subtract subtract two images

gimp manipulate appearance of images

xephem interactive ephemeris displays the sky

xmccd run a scientific ccd camera

xmtel run a telescope

To begin

• Make a directory to store your work with the commands cd to set to the top level directory of the astrolab account and mkdir myimages or whatever unique directory name you prefer.
• Copy the data to this directory with
  • cd /home/astrolab/moore/20041106 where ``20041106'' was the date of the observation. There may be more than one date, and if that is the case, then repeat this for the other dates to put all of the raw data into your own working directory.
  • cp * /home/astrolab/myimages/ where ``myimages'' is the directory you created above.
• Go back to your directory (cd then cd myimages)
• Try ls and you should see all the fits files and the notes file if it existed in the original directories.