Know about Astra Missile's Seeker

Fact for 6/6/2021



Astra uses a terminal active radar seeker, let's see the philosophy behind it. Other seekers are only receivers, but the one used in Astra is a transceiver a transistor cum receiver, it is basically a mini radar itself radars can be fooled and can be deceived , but the more a radar is closer to the target the lesser are the chances of fooling it. Since terminal guidance stage goes active when it is 'enough near’ the target the question weather the terminal active seeker be spoofed, jammed or decoyed is a big question. To counter the spoofing and jamming their is an effective technique, which is passive radiation homing . Spoofing the active seeker means using the radio waves coming from it and showing a false target, Jamming means shooting heavy pulses at an antenna in an order to overload and burn it from inside.
Here in both spoofing and jamming the enemy would be giving radio waves and the technique of passive radiation homing uses these same waves as 'feed’ and homes in on a target. During tests in March 2016 conducted near Pune, Astra Missile was tested, it was sought to be jammed to see how it performs in such a scenario at the time of war when the enemy tries to jam its operation. The ECCM (electronic counter-countermeasure) features of the missile to overcome any jamming were evaluated. “The trials were vigorous. But the state-of-the-art missile did very well,” said a source that reported this event.

Origin and development

Astra used 9B-1103M seeker which is used in R-77 missile variants. It is a multi-function doppler-monopulse active radar seeker. The seeker features two modes of operation, over short distances, the missile will launch in an active "fire-and-forget" mode. Over longer distances the missile is controlled by an inertial guidance autopilot with occasional encoded data link updates from the launch aircraft's radar on changes in spatial position or G of the target. As the missile comes within 20 km (12 mi) of its target, the missile switches to its active radar mode. The host radar system maintains computed target information in case the target breaks the missile's lock-on. Later on DRDO’s RCI developed an indigenous seeker it is a Ku band seeker which is manufactured by VEM technologies. During tests this new seeker performed very well and hit the PTA Lakshya. DRDO has now mated the Astra missile with indigenous KU-band Active radar seeker which is a miniaturised version of the seeker which DRDO developed some time ago for PAD
In India, R & D work began in 2016 for developing AESA-based X-band and Ku-band active seekers for both the XR-SAM long-range surface-to-air missile and the SFDR-powered Astra-2 BVRAAM, with Hyderabad-based Astra Microwave already having developed two types of such seekers, with work now underway on developing their Ka-band successors that too will be compatible with the Meteor BVRAAM. The Ka-band seeker with an active phased-array antenna (with 20km-range) and a secondary X-band passive channel will replace existing Ku-band seekers (with 6km-range) and provide higher resolution and countermeasures resistance.
Such seekers can effortlessly work across multiple frequencies simultaneously, which makes them not only better at finding objects, but are also more difficult to detect. In addition, electronically steered antenna beams also offer other improvements: it is possible to perform an adaptive antenna beam-forming based on antenna sub-group transmit (Tx) and receive (Rx) channels or even adjusting all the single antenna transceiver elements. This put us into a position to use algorithms of super resolution in order to recognise and localise jammer sources while concurrently conducting target acquisition and tracking.

info gathered by - exeter#3926 in Defence Matrix Discord Server