HARD 3D

The HARD 3D is an X-band (8,800–9,300 MHz) 3D search and target acquisition radar designed for Short-Range Air Defense (SHORAD) systems. The original HARD 3D, known as PS-91, is exclusively used by the Swedish Armed Forces. An improved version, the Improved HARD 3D, features alternate pulse repetition frequency (PRF) modes and the ability to locate hovering helicopters. Its 3D capability, up to a maximum elevation angle of 35 degrees, is achieved through a linear phased array antenna composed of 16 antenna groups, each driven by a novel transmitter module, which increases transmit power (65 W peak, 8 W average). This, combined with adaptive Moving Target Indication (MTI) filtering, nearly doubles the instrumented range to 20 km compared to the basic version, while maintaining a high antenna rotation speed of 40 rpm and a range resolution of 50 m and 0.5 degrees. The radar's search strategy allows it to cover the entire 35-degree elevation angle range after two rotations. The Improved HARD 3D is designed for low probability of intercept, making it difficult to detect with radar warning receivers and, according to the manufacturer, almost impossible to counter with anti-radiation missiles (ARMs). Key features include low-altitude target detection and electronic protective measures (EPM) capability.

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