Defining Scan Start and Stop Times

The parameters in the procedure group are defined as they apply to built-in observing procedures. You may use them for other purposes. If you change a parameter value, the value will be changed for all procedures that use it. There are nine generic parameters called parm1-9. These are not used by any built-in procedures. You may assign labels and units to these parameters when you attach your procedure to the the interactive part of GBT Observe.

For most observations procedures will be executed by the GBT as soon as possible, but the start time may be explicitly specified in either UTC or LST with one of the following two parameters. If both start_utc and start_lst are specifed, all but the last one set will be ignored.

$\parbox{6.25in}{ \begin{description} \item [proc.startutc]~~~ \b... ...ter:] \item[YGOR to GO mapping:] }{} \end{description} \end{description}}$

$\parbox{6.25in}{ \begin{description} \item [proc.startlst]~~~ \b... ...ter:] \item[YGOR to GO mapping:] }{} \end{description} \end{description}}$

The ``track'' procedure has three other timing parameters that are unique to it. A stop UTC or LST may be specified so that the scan will be started as soon as possible, but the scan is guaranteed to end at the specified time. This is useful for VLBI observations to keep schedules synchronized at different observatories. When a stop time is used the length of the scan will depend on when the telescope is able to get on position and initiate the data-taking process. If both stop_utc and stop_lst are specifed, all but the last one set will be ignored.

If a start time or no start or stop time is given, the length of a ``track'' scan is set by the scan_duration parameter. All procedure start and stop times are cleared after a procedure is executed so that the next procedure will be executed as soon as possible unless a new time is specified.

$\parbox{6.25in}{ \begin{description} \item [proc.stoputc]~~~ \be... ...ter:] \item[YGOR to GO mapping:] }{} \end{description} \end{description}}$

$\parbox{6.25in}{ \begin{description} \item [proc.stoplst]~~~ \be... ...ter:] \item[YGOR to GO mapping:] }{} \end{description} \end{description}}$