The main observing task, CAOBS, reads the schedule file in order to determine what sources are to be observed, for how long, and in what order. The schedule file also defines the frequencies, integration averaging unit and correlator setup to use.
You can use the program ATCASCHED (Section3.3.1) to prepare schedule files. (ATCASCHED is the linux version of the program SCHED than ran on the VAX computers. It is often referred to simply as SCHED for that reason.)
You should prepare at least two schedule files:
If your observation involves looking at five or more sources you are advised to create a text `command procedure' as described below. ATCASCHED can then read this file and convert it to a schedule file.
For observations of many sources, use the ATMOS program in MIRIAD to solve the ``travelling salesman'' problem and optimise the order in which your sources are observed.
It is often the case with synthesis instruments that system errors lead to artefacts at the centre of the field. It is therefore advisable to displace the source position a few synthesised beamwidths from the field centre. Note that ATCA software never checks to see how close you are to the sun!