As taken from a US Army technical report written about the Spetnaz. It should not be a surprise that not all former USSr specops soldiers did not know about this device. After all not all US Special Forces were arware of the Special Purpose 308- gear (see my thread on these items). Am trying to get a good photo of the set up on a small tripod and will post it as soon as I can. Actually I took 2 different write ups about the missile and combined them.
Spetsnaz Opsremote SA 7 set up
A spetsnaz weapon known as theStrela-Blok, was used in the second half of the 1960s and the first half of the 1970s. It is quite possible that by now it has been very substantially improved. In a sense it can be described as an anti-aircraft mine, because it operates on the same principle as the mine laid at the side of a road which acts against a passing vehicle. It is related to mines which are based on portable grenade-launchers which fire at the side of a tank or an armoured personnel carrier.The Strela-Blok is an ordinary Soviet Strela-7 portable missile. A spetsnaz would carry one or several of these missiles with it. In the area of a major airfield the launch tube would be attached to a tall tree (or the roof of a building, a tall mast,a hayrick) and camouflaged. The missile was usually installed at a short distance from the end of the runway. That done, the group leaves the area. The missile was launched automatically. A clockwork mechanism operates first, for safe separation time of the then, when the set time has run out (from an hour to several days) an acoustic detector is switched on which reacts to the noise of an aircraft engine. The acouostic device was able to tell the difference of an aircraft taking off or landing, but was normally set for targeting aircraft in take off operations. At a preset decible reading the targeting system fired the missile, the infra-red warhead reacts to the heat radiated bythe engine, follows the aircraft and catches up with it.
The Soviets developed a special version of the Sa-7 for use by the special operations forces, the spetznaz. It was called the Strela-Blok. It was an automatic missile, designed to be emplaced before hostilities near an enemy (i.e., NATO) air base. A timer would be set for it to become "active." Afterward, a directional microphone, aimed at the air base, would detect the sound of aircraft engines.The acoustic mike was linked to a frequency filter, a Doppler sensor. The Doppler sensor was connected to the firing mechanism through the power module(a separate power module from the thermal battery normally used with the launcher). In this set up the normal thermal battery and the handle trigger were replaced with a different triggering system. This system provided battery power to the acoustic sensor and power to launch the missile.
Usually, the mike was designed to aimed at the end of the runway, at a45-degree angle upward. It would detect all aircraft noise from ground level to12 degrees past vertical in the sky.
When an aircraft passed overhead, the Doppler sensor would compute when theDoppler curve began to decrease, indicating that the closest approach had justbeen passed. It would send an electrical signal to the firing mechanism, whichwould confirm an infrared lock on the target. The rocket would then fire,sending it toward the aircraft at 1,600 kilometers per hour (about 1,000 mph).
