Observing

HartRAO supports a variety of observing programs much the same as in other observatories. HartRAO is unique however in the fact that a number of different programs can be scheduled simultaneously. Conflicts are avoided by the scheduler and by a kind of gentle(wo)man's agreement. This means that long term monitoring programs can be scheduled simultaneously with short term programs . It also means that telescope time is used efficiently. This unique ``multi-tasking'' feature of the HartRAO observing scheduler has to be supported by the NCCS. Another unique feature of the HartRAO system is the large amount of unattended observing which is done. The NCCS has to support this feature as well.

This section will explain the main observing modes used at HartRAO and try to list the main features which are necessary and have to be supported by the NCCS.

They must be written in a pseudo control language which resembles a mixture of C and English. The algorithms must be broken down into short atomic actions. Control flow must be indicated by means of the following control statements :

if ( condition ) then { statement(s) } else { statement(s) }

while ( condition ) do { statement(s) } 

repeat { statement(s) } until ( condition )

for ( i = 0 ; i < N ; i++ ) do { statement(s) }

switch ( condition ) { case (1) : { statement(s) ; break }
                                  .
                                  .
                                  .
                       case (n) : { statement(s) ; break }
                       default  : { statement(s) }
                      }

Comments can be specified in the standard C or C++ style i.e.

/* this is a short comment */

// the whole line is a comment

Here is an example of using this language to specify an algorithm one of the authors uses for waking up in the morning :

repeat
{
   sleep
   alarm rings
   switch off alarm
   if ( first time ) 
   then 
   {
      sleep
   }
   else 
   {
      wakeup
   }
} 
until ( awake)
wash face
brush teeth
while ( not really awake )
{
   make coffee
   drink coffee
   meditate on life
}
if ( dirty )
then
{
   take a shower
}
get dressed
go to work

The NCCS must support the observing algorithms below either as they are described here or in an equivalent manner.

$\clubsuit$

ALL ALGORITHMS MUST BE SUBMITTED BY 1/12/95.