Radar Concept & History

Drodion’s solution is what is known as a ‘passive bistatic radar’(PBR).  The first PBR experiments were conducted in the United Kingdom in 1935 by Robert Watson-Watt.  He demonstrated the principle by detecting a Heyford bomber at a distance of 12km by using the BBC’s shortwave transmitter at Daventry as the illumination source.

Passive Radar

Watson-Watt then went on to develop the Home Chain which was the first early warning radar network in the world and it proved to be decisive during the Battle of Britain in 1940.  Home Chain consisted of forty active radar stations located around the British coastline. It wasn’t until after the war that the British discovered that the German’s had later developed a PBR system, which used the Home Chain broadcast signals as the illumination source. The German’s had turned the great British asset on its head; and were detecting British aircraft by passive means.

Find the Location, Speed & Direction of One or Many Targets

A radar works by processing a received signal; comparing it with the transmitted one; and then analysing the differences to find the location; speed, and direction of one or many targets. In the case of active radars, the transmitted signal is generated by the radar system itself. Active radar can be very costly as it needs to generate and emit the energy source, then process the signals.

Passive radars are opportunistic and use existing energy sources already present in the environment. Examples include; commercial broadcast signals (e.g. FM-radio or digital broadcast networks); communication network signals such as Global Navigation Satellite Systems (GNSS); or mobile phone networks. These existing sources are referred to as non-cooperative sources of illumination.

Passive Radar Concept for Detecting Drones or UAVs

Drodion mainly uses the GNSS signals due to their global coverage. However, satellite signals typically have a relatively weak power when they reach the ground and consequently they have not been used as an illumination source for bistatic radar.  Despite this, after many years of research, Drodion has developed a way to be able to identify and process these signals by using its patent pending technology and algorithms. This means that Drodion can now provide a unique and cost effective solution to detect drones, in any environment, or in any location.

Passive Radar
Passive Radar Airport Drone Detection Systems

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