 AN/FPS-23 radar (on tower) | |
| Country of origin | United States |
|---|---|
| Manufacturer | Motorola |
| Type | early warning radar |
| Frequency | 475 - 525 MHz (UHF) |
| Range | 50 nautical miles (93 km) |
| Diameter | 20 by 6 feet (6.1 by 1.8 m) |
| Power | 1 kW |
| Other Names | Fluttar, Type "F" |
The Motorola AN/FPS-23 was a short-range early warning radar deployed on the Distant Early Warning Line (DEW Line). It was used as a "gap filler", looking for aircraft attempting to sneak by the DEW line by flying between the main AN/FPS-19 stations at low altitude. It could detect aircraft flying at 200 feet over land or 50 feet over water.[1] The system was known as Fluttar (flutter radar) during its development at the Lincoln Laboratory, and this name was widely used for the production units as well. It was also sometimes known as "Type F". The system went into operation in 1957.
A major design goal of the FPS-23 was to use the Doppler effect to filter out low-speed objects. Migrating birds flying by the similar Mid-Canada Line (MCL) stations had rendered that system useless during spring and fall. FPS-23 proved to be largely free of this problem, but instead was constantly triggered by light aircraft flying anywhere near the stations. As these were used for communications and crew rotations, the FPS-23 system ultimately proved to be as ineffective as the MCL and the system was shut down in 1963.