The National Interest:
The solicitation is sparse on details, such as the desired range of the detection system. Nor are there indications of what the robot boat would look like, except that it is 10 feet long and 2 feet wide, suggesting that the air force (or the navy) has a boat already in mind.
Sea-skimming missiles have been the nemesis of surface warships since the 1970s. Weapons such as France’s legendary Exocet, America’s Harpoon or Russia’s Zircon threaten even the most powerful warships with destruction.
Sea-skimmers fly low to avoid radar detection. If warships can’t spot these missiles in time, they can’t shoot them down with point-defense cannons or employ countermeasures such as jamming or decoys. So, the U.S. Air Force has an idea: send out robot boats to detect sea-skimming missiles and give manned warships time to defend themselves.
The goal is to “identify and demonstrate technologies that can detect and track low radar cross-section, high-speed, low-altitude weapons over a large area of water,” according to the Air Force research solicitation. “Tracking on water ranges is limited by the inability of conventional radars to track over-the-horizon.”