This is very cool. Check out the video.
   ----
   [1]http://www.raytheonmissilesanddefense.com/news/2023/03/27/over-the-h
   orizon-radar
   Raytheon Technologies is building a next-generation over-the-horizon
   radar, offering advanced detection of cruise missiles.
   April 05, 2023
   For decades, the focus of missile defense for the U.S. and its allies
   has been on nuclear ballistic weapons, which can fly high and fast to
   strike a target half a world away.
   But another threat lurks beneath: cruise missiles, which fly lower and
   slower but, as seen in strikes on Ukraine, can carry devastating
   payloads.
   One important defense against those threats are surface-based radars
   that can see over the horizon to provide earlier warning and cue
   defensive measures.
   Raytheon Technologies is using its decades of expertise as an
   integrator of missile defense systems to develop a first-of-its-kind,
   next-generation over-the-horizon radar to defend the homeland. The new
   system will be able to quickly detect, track and classify cruise
   missiles – day or night, and in any conditions, including when the
   northern lights, also known as the aurora borealis, are on display.
   “The next-generation over-the-horizon radar represents a quantum leap
   forward in our ability to not only detect and track aircraft and
   surface vessels, but also detect and defend the homeland against cruise
   missiles and other weapons,” said Paul Ferraro, president of Air Power
   at Raytheon Missiles & Defense, a Raytheon Technologies business. “With
   its unprecedented sensitivity, this new radar technology will be a game
   changer, providing our military with an unparalleled advantage in
   cruise missile defense.”
   Over-the-horizon radars can detect objects hundreds to thousands of
   miles away beyond the range limit of conventional radars. They operate
   in the high-frequency band of 5 MHz to 35 MHz, using powerful radio
   signals transmitted by a large antenna.
   What sets them apart from other missile defense systems is that they
   can see around the curves of Earth. They do that through what is
   essentially a bank shot: they bounce their signal off the ionosphere,
   then the target, which reflects the energy back to the ionosphere and
   ultimately to the radar's receiver.
   The next-generation over-the-horizon radar builds on technology and
   design that power a system known as ROTHR, which the U.S. Navy uses as
   its primary detection system for border security and drug smuggling.
   That system, which stands for Relocatable Over-The-Horizon Radar, is
   built by Raytheon Technologies. The company's experts are leading the
   integration of several advancements in its maritime capabilities.
   And that work, naturally, will benefit the development of a
   first-of-its-kind system, with a 2D array and digital receiver.
   “We’re leveraging more than three decades of ROTHR and HF (high
   frequency) technologies across our portfolios as well as research and
   investment to deliver a next-generation system built to detect advanced
   threats,” program manager Jeremy Hurley said.
   Raytheon Technologies has worked with the U.S. Navy, U.S. Air Force,
   the U.S. Missile Defense Agency and research laboratories to
   continuously improve technologies critical to over-the-horizon radars,
   such as systems processing.

References

   1. http://www.raytheonmissilesanddefense.com/news/2023/03/27/over-the-horizon-radar