High-frequency system offers low-level surveillance range of more than 200km

AMS is putting its high frequency over-the-horizon surface radar (HFSWR) into production as the Anglo-Italian company believes there are several sales prospects for the system.

HFSWR uses surface waves to propagate an HF signal across the sea surface to extend the radar's low-level surveillance range to over 200km (110nm), which is beyond the radar horizon. As well as seeing targets above the radar horizon, HFSWR can also detect surface vessels, low flying aircraft as well as cruise and sea-skimming missiles.

Andy Wilkins, AMS radar systems sales manager, says the prospects for the system mean the company is putting it into production, but declines to specify any interested parties. HFSWR has potential civil uses, including fishery protection and safety of shipping. Wilkins says the radar would typically be located on a beach looking out to sea, providing 120¡-azimuth of coverage.

AMS has developed new tetrahedral doublet antennas that co-locate the transmit and receive elements. The array has been tested at AMS's site in Essex, UK, overlooking the North Sea. The company says an array comprises multiples of 16 tetrahedral elements and that digital beamforming allows multiple beams over the whole coverage sector.

Although HF radars are not new, commercial off-the-shelf processing means that such systems are now a practical proposition, says AMS. Wilkins says the radar is affected by environmental conditions, including sea state, and acknowledges that the Gulf provides suitable conditions. The system was showcased at the IDEX show in Abu Dhabi last week.

AMS was also involved in Australia's JORN long-range radar, which is also an HF system but bounces signals off the ionosphere rather than allowing the waves to propagate across the sea surface.

Source: Flight International