Abstract: The invention relates to instruments which include radiometers and which generate a laser beam for striking a target at a distance to assist in aiming the instrument at a selected area of a target. Provision is made for splitting a single beam, used for instance for centering the instrument on the target, into a plurality of beams for creating a pattern or for defining an area on the target. When a single beam is split, the resultant plural beams produced are of relatively lower power, which may be insufficient for visibility on a target at a distance. The invention provides apparatus to increase the power of the single laser beam when it is split, so as to provide plural beams of appropriately higher power and visibility.