The basics needed to write most procedures are outlined here. The more advanced aspects of integrating a procedure into GBT Observe are given elsewhere , but these are not required to use your own procedures. A typical procedure looks like the following one, called 'stepline'. It does five scans at equally spaced points along a line of constant declination. All scan-related keywords, like scan duration, are assumed to have been set before invoking this procedure.
Glish syntax is case sensitive so keep everything lower case, particularly the function name .
Also, do not use underscores in the function name so that the table parser can recognize it. Aliases are not recognized in procedures because they are defined by the user when a table is executed. Many of the keyword values are strings with a limited set of legal values. All of these legal values are available as string constants in glish which you can use in conditional tests. Use the GBT Observe help facilities or read the web documentation to find a list of legal string constants for any keywords you want to use.