Getting started

In order to work through the recipes you should use a colour display capable of receiving X-output (typically an X-terminal or a workstation console). Before starting you should ensure that your display is configured to receive X-output.

To work through the recipes as they are presented you should take a copy of the example data provided with the cookbook. Proceed as follows.

1. Create a new subdirectory, perhaps called sc5, in some convenient location and make it your current directory:

   mkdir sc5
   cd sc5

2. Copy the example data files into this subdirectory:

   cp -r /star/examples/sc5/data .

   Note that the data files are kept in various subdirectories of /star/examples/sc5/data and a recursive copy (the `-r' option) is used to preserve this structure. Each subdirectory contains a different type of file, as follows:

   bias   

   - bias frames,

   flats  

   - flat fields,

   targets

   - images of target astronomical objects.

   Keeping the different types of files in separate subdirectories makes them easier to manage.

As an alternative to using the data supplied with the cookbook you could use data of your own. Suitable data are available on the CD-ROM Astronomical Images[14] or from the ING data archive. However, if you substitute your own data you will need to ensure that you know the extent of any bias strips on the CCD frames and similar auxiliary information. For data from Astronomical Images these details are given in file descript.ccd included on the CD-ROM.