Editing Command guidance (section)

====Line of sight beam riding guidance (LOSBR)====
{{Main|Beam riding}}
LOSBR uses a ''beam'' of some sort, typically [[radio]], [[radar]] or [[laser]], which is aimed at a target and detectors on the rear of the missile keep it centered in the beam. Beam riding systems are often [[SACLOS]], but do not need to be; in other systems the beam is part of an automated radar tracking system. An example is later versions of the [[RIM-8 Talos]] missile as used in Vietnam: the radar beam was used to take the missile on a high arcing flight and then gradually brought down in the vertical plane of the target aircraft, the more accurate [[semi-active radar homing]] (SARH) being used at the last moment for the terminal homing and strike. This gave an enemy pilot the least possible warning that the aircraft was being illuminated by missile guidance radar, in contrast to search radar. This is an important distinction, as the properties of the signal differ, and are used as a cue for evasive action.

LOSBR suffers from the inherent weakness of inaccuracy with increasing range as the beam spreads out. Laser beam riders are more accurate because beams of lasers spread less than of radars, but are all short-range, and a laser can be degraded by bad weather. In contrast, SARH becomes more accurate with decreasing distance to a target, so the two systems are complementary.