Beam-riding SACLOS
With beam-riding SACLOS, the sighting device emits a directional signal directed toward the target. A detector in the tail of the missile looks for the signal. Electronics in the missile then keep it centered in the beam. It differs notably from the SARH (semi-active radar homing) and SALH (semi-active laser homing) in which target is illuminated by a powerful emitter and a sensor on the head of missile direct it to the target.
Radar was the most common form of SACLOS signals in early systems, because, in the anti-aircraft role the target is typically being "illuminated" by a radar signal anyway. However, a beam-riding missile flies directly at the target, which is often inefficient for a high-speed target like an aircraft. For this reason, most anti-aircraft missiles follow their own route to intercept the target, and do not "ride" the beam.
A more modern use of beam-riding uses laser signals because they are compact, insensitive to distance and are difficult to detect and jam.
This was also one of the main advantages over concurrent SALH systems: regarding detection laser riding beam emitter is typically a low powered device and does not need to be pointed immediately to the target, and because the missile sensor "looks" backward to it, the whole system is impervious to most jamming devices. Another advantage in antitank applications is that the backward-looking guidance system does not interfere with the process of jet formation of HEAT charges, thus maximizing weapon's effectiveness.
However, such systems don't allow for a top-attack mode, or target illumination from a different source than the launcher itself, so choice between the two operating modes may vary between operators.
The main disadvantage of both SACLOS guidance systems in an anti-tank role is that working on angular differences evaluation, it doesn't allow any notable separation between guidance system and missile launch post opposite to former MCLOS ones, thus allowing updated version of such anti-tank weapons (notably AT-3 Malyutka) to still remain in service in some countries.
Examples:
- Kornet
- Starstreak
- Ingwe
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