Surface-to-air systems explained layer by layer: sensors, interceptors, command links, magazine depth and the cost per engagement each design accepts.
Radar is a line-of-sight instrument on a curved planet, so a low-flying target hides behind the earth itself — and the entire architecture of layered air defense exists to compensate.
Patriot is a long-range surface-to-air system built around one multifunction radar and two very different interceptor philosophies — a large blast-fragile warhead missile and a hit-to-kill one.
Lockheed Martin's PAC-3 MSE has moved from Army Patriot launchers to the Navy's Mark 41 Vertical Launching System, and official statements and procurement data tie the shift less to any new threat the missile can counter than to production capacity and a fleet still learning to reload its magazines at sea.
One interceptor tries to strike the target itself; the other detonates a wall of fragments nearby. The choice shapes the whole missile.
ESM, infrared, and acoustic receivers hold the air picture in silence, then cue the radar for a few seconds of transmission — the IADS pattern explained.
Drones span five orders of magnitude in size and cost, and that spread defeats any one defense.