Ground-to-Air Transmitter Facilities (GAT Facility) were surface-to-air missile radio uplink stations of the
United States Air Force
The United States Air Force (USAF) is the Air force, air service branch of the United States Department of Defense. It is one of the six United States Armed Forces and one of the eight uniformed services of the United States. Tracing its ori ...
.
They were located near
CIM-10 Bomarc
The Boeing CIM-10 Bomarc ("Boeing Michigan Aeronautical Research Center") (IM-99 Weapon System prior to September 1962) was a supersonic ramjet powered long-range surface-to-air missile (SAM) used during the Cold War for the air defense of No ...
bases (e.g.,
Suffolk County Missile Annex on
Long Island
Long Island is a densely populated continental island in southeastern New York (state), New York state, extending into the Atlantic Ocean. It constitutes a significant share of the New York metropolitan area in both population and land are ...
) for
command guidance
Command guidance is a type of missile guidance in which a ground station or aircraft relay signals to a guided missile via radio control or through a wire connecting the missile to the launcher and tell the missile where to steer to intercept its ...
of the Interceptor Missiles.
[Distances of each GAT Facility from the Launch Area were tbd (Patrick), tbd (Hurlburt)(http://www.radomes.org/museum/HurlburtFieldBOMARCFLGATSite.html/documents ) 1 mile ( McGuire), 2⅓ mi (Suffolk), 2¼ mi (Otis), 4½ mi (Dow), 4½ mi (Langley), tbd (Sault Ste. Marie), tbd (Ottawa).] The unmanned sites with a transmitter building and 2 antenna towers converted the digital "midcourse guidance commands" (after the launch/climb and before the homing dive) received from an
AN/FSQ-7 Combat Direction Central into the transmitter building's
Digital Data Receivers, processing 28 channels of uplink data.
Processing by the
AN/GKA-4A's demultiplexer group prepared the SAGE data for
amplitude modulation
Amplitude modulation (AM) is a signal modulation technique used in electronic communication, most commonly for transmitting messages with a radio wave. In amplitude modulation, the instantaneous amplitude of the wave is varied in proportion t ...
on separate frequencies for each missile (FDDL:
frequency-division data link), e.g., 3 missiles were simultaneously controlled in a 1960 test. An
AN/GRT-3 transmitter provided the modulated signals to a UHF Klystron high power amplifier—dual chains of components provided redundancy, including 2 exterior GAT Antennas on GAT Towers from which a missile's "command receiver" demodulated the signal. A single local monitoring cabinet allowed review of either chain's function (e.g., during test input to the dummy load), ventilation provided cooling of the building equipment, and "three 150 KVA diesel driven generators housed in the GAT building" provided power.
For the advanced Bomarc (IM-99B), a
Time-Division Data Link was planned for GAT Facilities to provide an
electronic counter-countermeasures
Electronic counter-countermeasures (ECCM) is a part of electronic warfare which includes a variety of practices which attempt to reduce or eliminate the effect of electronic countermeasures (ECM) on electronic sensors aboard vehicles, ships and a ...
capability using a "directional hlgh-gain data link antenna…composed of 16 stationary segments in a circular pattern 60 feet high".
References
* {{Cite report , date=December 3, 1959 , title=IM-99A Bases Manual , location=Seattle, Washington , publisher=Boeing: Pilotless Aircraft Division , quote=Differences in the Langley Base layout are due to planning for accommodation of the advanced missile system
M-99Bground equipment with
reviousequipment for the IM-99A system
External links
Remaining Langley GAT building and tower
Aerial warfare ground equipment
Equipment of the United States Air Force
Anti-aircraft warfare
Defunct radio stations in the United States