The SIM command is used to perform a lunar siting on the brewer when the lunar disc is used as the radiation source. After the date, time, and station co-ordinates have been set accurately, a set of four controls on the front of the instrument are used to introduce ‘Horizon’ and ‘North’ corrections which compensate for any offsets that may occur. These corrections are saved and used by the software in future pointing calculations.

Refer to the Brewer Site Operator's Manual in Section 2.2 for more information on how to preform a sighting.