Raytheon Wins $45 Million Re-locatable Over-the-horizon Radar System Contract

Raytheon is being awarded $45 million contract for fully integrated replacement shelters for transmit array, transmit site monitors and receive site monitors for the Re-locatable Over-the-Horizon Radar system (ROTHR). 

Work is expected to be completed by Sept. 2022, the US department of defense said in a statement Monday.

The ROTHR uses high-frequency radar waves that bounce off a layer of the atmosphere called the ionosphere to provide long-range over-the-horizon radar coverage. It achieves long ranges just like shortwave radio.

ROTHR uses HF radio waves, which are particularly susceptible to interference from lightning almost anywhere in the world. HF signal reception also changes throughout the course of the day and the seasons, as well as at night, so ROTHR poses a particularly difficult digital signal processing (DSP) problem.