In track-while-scan mode the radar has the ability to acquire and lock/track multiple targets while simultaneously providing a view of the surrounding airspace, which in turn aids the pilot and or operator in maintaining better situational awareness.
From then on it would automatically keep its antenna pointed at the target, feeding out accurate direction, altitude and range information on a B-Scope display.
Advances in electronics meant it was only a matter of time before automated radars like the SCR-584 could be reduced in size and weight enough to fit into an aircraft.
To improve the operator's ability to read the display, the oscilloscopes typically used a slowly fading phosphor as a crude form of "memory".
A second system continuously reads the data in the track files from memory, and displays this on the radar as a series of annotated icons.
So in spite of the radar not constantly painting the target as it would in a traditional lock-on, enough energy is sent in that direction to allow a missile to track.
It was actually the Soviet-made missile guidance, target detection and tracking radar known as B-200,[4] firstly designed in 1953 by KB-1 (today known as NPO Almaz), as a part of multi-channel, stationary anti-aircraft missile system designated as S-25 (Sistema-25, initial name Berkut - Golden eagle, in English) or SA-1 Guild (by NATO designation), which was intended exclusively for defense against possible massive air raid on Moscow and especially Kremlin from long-range strategic USAF bombers[5] (especially the ones like B-47 and later B-52, capable of stratospheric flights, which made them completely immune to ordinary anti-aircraft guns).
Since the S-25 was also designed as the first multi-channel missile system in history (the first one which had the ability to engage multiple targets completely simultaneously - as much as twenty targets by a single battery, each with up to three missiles),[6] it thus required a proper radar capable of fulfilling such a demanding task, what ultimately resulted in creation of the B-200, as the very first fire-control radar intended for multiple guidance of missiles on multiple different air targets, what was ensured exactly by its TWS ability.
Rather than using later phased-array antennas and multiprocessor digital computers (both which did not exist yet back in the time) the TWS ability in B-200 was actually achieved by an alternative method, that is, by the so-called "brute use of force" approach (B-200 featured massive and very bulky electronics[7] featuring many analog computers together with its own power supply in shape of heavy generators, regulators, stabilizers and ventilators, all which were placed inside a relatively large concrete bunker).
The B-200 also featured very unique and advanced design for its time as well as an unusual operating mode; consisting of two symmetrical antennas (one intended for azimuth and the other one for elevation surveillance), each featuring two hexagonal, diamond-shaped discs (each as much as 10 meters high), both which were rotating around its own axles (like a propeller or windmill) in mutually opposite directions and as fast as 50 turns per minute, which enabled them as much as target scans.
It was the first Western radar which featured ability to engage aircraft on multiple airborne targets while still simultaneously scanning for new ones.