Thales is targeting the huge potential for unmanned aerial vehicles (UAVs) for coastal surveillance in Southeast Asia by offering a compact, lightweight radar system called the Coastmaster. The UK group’s aerospace division developed the 66-pound system from the ground surveillance radar being fitted to the British Army’s Watchkeeper UAVs. (Helicopters and small manned aircraft could also carry the new radar.)
“This radar is particularly suitable for the detection of small, fast-moving targets in estuarine regions and those with a large number of islands and waterways,” said James Lazell, Thales UK’s program manager for UAVs. “The applications include anti-drug trafficking, counterterrorism and the protection of valuable maritime assets such as offshore oil rigs, ecological zones and fisheries,” he added.
In the Watchkeeper radar, which features SAR (synthetic aperture radar) and GMTI (ground moving target indicator) modes there is no requirement for maritime reconnaissance (MR). However, with decades of experience in the maritime field–with the Searchwater series, employed on UK Nimrods and helicopters, and the OceanMaster series, which are exported–Thales UK is adding MR, Inverse SAR and Maritime MTI modes to the Coastmaster, which also employs standard SAR and GMTI. The new radar can scan by sector, by broadside strip map, by spotlighted area or by continuous 360-degree rotation.
However, as Lazell noted, compared with detecting targets in the open ocean, it’s quite a challenge to detect them in littoral and riverine environments. Thales is bringing particular techniques to bear on the problem–pulse compression, adaptive thresholding and scan-to-scan integration.
Small Target Capability
The slow scan rate (6 rpm) enables the Coastmaster system to detect small targets, such as fast-attack boats and even jet skis constructed of composite materials. A profile of the target can be built by using “A-scan ranging,” still in the MR mode. The Inverse SAR mode can then provide higher resolution, leading to target classification.
In the SAR mode, which provides very good resolution at a range of up to 12 miles, the Coastmaster can detect nonmoving targets, according to Lazell. SAR allows for change detection over periodic revisits, while GMTI and Maritime MTI provide the ability to overlay moving targets on digital maps and to replay the radar history to identify change.
The maximum range of the Coastmaster radar is about 25 miles, achieved with a peak power of only 620 watts. The system also operates in lower power standby modes that require 125 to 500 watts. It is self-cooling and the whole thing fits in a turret no bigger than those used to house EO/IR systems, with which it is interchangeable. “But unlike an IR sensor, the Coastmaster provides rapid classification of targets in all weather and sea states,” Lazell claimed.
Flight trials of the Coastmaster radar began late last year in a light aircraft. “We are getting good results,” a Thales UK spokesperson told AIN. Lazell said the company has already received export inquiries and can deliver within 15 months.