The AN/FPS-117 is an L-band active electronically scanned array (AESA) 3-dimensional air search radar first produced by GE Aerospace in 1980 and now part of Lockheed Martin.

To fill a need for the US Marine Corps, GE developed the transportable AN/TPS-59, and later combined design elements to produce the smaller AN/TPS-77 which is even more mobile, requiring only one prime mover in some deployment scenarios.

[3][4] A key problem for radar systems of the 1950s was the introduction of the carcinotron, a microwave-producing tube that could be rapidly tuned across a wide bandwidth.

Scanning rapidly, it appeared to be a constant radiator across an entire band, creating a powerful form of barrage jamming.

By the late 1970s all of these technologies were maturing, and the possibility of fully active radars at reasonable price points emerged for the first time.

These used two 500 kW magnetrons on huge always-turning parabolic antenna systems and rooms filled with tube-based electronics to drive them.

Desiring a much simpler, and less-costly, system, in 1977 the Rome Air Development Center (RADC) began the "Seek Igloo" project to find a replacement for the FPS-19 that would require less power and would run for extended times without maintenance.

Conversations among NORAD commands about the DEW line had been ongoing for some time, and the Royal Canadian Air Force was aware of the plans to convert to the new radars.

As part of the 24-hour whirlwind Shamrock Summit in 1984, Canadian Prime Minister Brian Mulroney and US President Ronald Reagan signed an agreement to create the North Warning System to replace DEW.

The RAF planned to replace Linesman with the IUKADGE network using the Marconi Martello radars, but as this system dragged on they eventually purchased two AN/FPS-117 as well.

As the first FPS-117 systems were being tested, the US Marine Corps sent out a tender for an air-warning radar with long range and good jamming rejection.

The main antenna was mounted on a custom trailer and offloaded at the operational site and then raised and leveled using hydraulic jacks.

The system is a long range (up to 250 nautical miles or 460 kilometres),[6] L-band pencil beam search radar with solid-state transmitters.

The combined power of the entire array is about 25 kW,[6] much lower than the multi-megawatt transmitters found in earlier radar designs.

The system design includes a redundant architecture with computer software remote controlled and monitored operations to minimize manning requirements.