AWS-4

The AWS-4 is an S-band (2.7-3.1 GHz) 2D naval radar designed in the late 1970s for surface and low-level air search. Its lightweight antenna and low-volume transmitter make it suitable for installation on fast attack craft and patrol vessels. The system provides surface and air tactical surveillance and target designation to weapon systems, detecting surface craft at the horizon and other targets up to 60 nautical miles (110 km) at 38,000 feet with an 80% detection probability. The antenna is a double-curved, fiberglass-reinforced plastic parabolic reflector with a galvanic metal coating, providing a cosecant-squared pattern and incorporating feed horn radiators for an interrogator. The AWS-4i is an upgraded version featuring a coherent-on-receive moving target indicator subsystem with automatic plot and track extraction, variable polarization to mitigate precipitation effects, and a transmitter utilizing tunable magnetrons operating in either the 2.7-2.9 GHz or 2.9-3.1 GHz range.

radartutorial.eu: https://www.radartutorial.eu/19.kartei/07.naval/karte087.en.html