Operation Igloo White
The Operation Igloo White (also briefly Igloo White ) was an American military operation in the Vietnam War in the years 1968 to 1973. The background was the planned destruction of the well-camouflaged Ho Chi Minh path , a logistical network of roads and other traffic routes, which led from North Vietnam via Laos and Cambodia to South Vietnam. For this purpose, electronic sensors were dropped from aircraft as part of the operation. These registered noises and reported them to nearby low-flying aircraft.
history
The operation was launched by Secretary of Defense Robert S. McNamara on September 16, 1966 . The program cost approximately $ 1.7 billion to develop and deploy and consisted of 20,000 battery-powered electronic sensors. These sensors cost approximately $ 1 billion a year to monitor and replace. Three different models of sensors were used.
The acoubuoy were sensors equipped with microphones that were parachuted down. You should get caught in the branches of a tree. These sensors could detect noises from vehicles at a distance of up to 1000 meters and people at a distance of up to 400 meters. Noises were broadcast over the radio. The range of the radio signals was over 50 kilometers. The VHF band between 168 and 174 MHz was used as the frequency . The sensor battery lasted about 30 days.
Air-Delivered Seismic Intrusion Detectors (ADSID) responded to vibrations in the ground caused by vehicles or people. They were simply thrown off, with the tip rammed into the ground, or laid by ground troops. They were secured against manipulation. Their range was much less than that of the Acoubuoy , 100 meters for vehicles and 30 meters for people. The battery life of the ADSID, however, was longer than that of the Acoubuoy . The ADSID were well camouflaged; only the camouflaged antenna protruded from the ground. These sensors weighed around 12 kilograms.
Mini-Seismic Intrusion Detectors (MINISID) were sensors that were designed by ground troops and responded to changes in the magnetic field. These sensors also sent signals in the VHF band. Later in the war, sensors were also used that could detect the electronic ignition of vehicles (EDET III).
The cost of an ADSID sensor was $ 619, an ACOUSID sensor was $ 1,452, and an EDET-III sensor was $ 2,997.
The sensors of anti-submarine aircraft OP-2E of the US Navy were often exposed. The radio signals were received from EC-121R electronic surveillance aircraft or from remote-controlled, unmanned aircraft such as a converted Beech 36 Bonanza . The planes transmitted the radio signals to the Infiltration Surveillance Center , or ISC for short, at the Thai air force base in Nakhon Phanom , Thailand . UHF in the 2.3 GHz range was used for this. The information was analyzed by System / 360 computers (IBM) . Analysts tried to determine the location, speed and direction of the vehicle or people. This information was passed on to Forward Air Controller, or FAC for short. Often this information was inaccurate or incorrect because the sensors also responded to animal movements. The US Air Force claimed the program was a complete success. In the early days of the program ( 1966 - 1967 ) 49 371 trucks had been tracked down. Of these, 10,472 could have been destroyed or damaged. For the year 1970 - 1971 the Air Force estimated that the program was involved in the destruction of 25,000 trucks. These numbers are considered to be embellished.
Many of the sensors were able to be switched off by the North Vietnamese. They were able to locate and destroy the sensors with radio direction finding. Sometimes the sensors were tricked by using sounds played by cassette recorders. Despite these failures, the technology was used on the border with Mexico from 1972.
Technical details
The sensors worked on ultra-short wave frequencies with an output power of 2 watts . If a sensor was activated by a noise or vibration, a digital signal with an identifier was sent out. 39 frequencies were available. Hundreds of different identifiers could be used. The EC-121R were equipped with multiple receivers that could receive the frequency range between 161,500 MHz (channel 0) and 175,750 MHz (channel 39). The bandwidth of a channel was 250 kilohertz. There was a console with lights that indicated the identifier of the received signal. The technique was originally developed for submarine hunting. There were 8 AN / ARR-52 receivers in a console on board the aircraft. There were 4 consoles in the aircraft, which meant that up to 24 frequencies could be monitored in parallel. An operator was able to activate the sensor to send ambient noise. Usually the signals were forwarded to the ISC via the UHF link. But sometimes the link failed or the data center in Nakhon Phanom was out of order. In these cases, the operator on board could also evaluate the signal from the probe himself.
The EC-121R were stationed at the air base of the Thai Air Force in Korat, briefly KRTAFB. They belonged to the 553 Reconnaissance Wing . Often whole fields or chains of sensors were laid out. The ISC collected the activations of the sensors and the computers generate statistics, forecasts and maps.
Web links
- How the Vietnam War Brought High-Tech Border Surveillance to America
- Air Force Magazine Igloo White
- Bugging the Battlefield . Department of Defense, National Archives and Records Administration, 1969, 00:30:28.
literature
- Correll, John T. Igloo White , Air Force Magazine. November 2004, Vol. 87, No. 11.
- The RAND Cooperation US Air Ground Operations Against the Ho Chi Minh Trail, 1966–1972
- Jack Sikora, Larry Westin Batcats: The United States Air Force 553rd Reconnaissance Wing in Southeast Asia
- John T. Halliday: Flying through Midnight: A Pilot's Dramatic Story of His Secret Missions over Laos during the Vietnam War, Charles Scribner's Sons, New York 2005, p. 17 f.
See also
Individual evidence
- ↑ Vietnam War: The City That Nobody Was Allowed To Know. In: Spiegel Online photo gallery. November 14, 2008, accessed January 22, 2017 .
- ^ The RAND Cooperation US Air Ground Operations Against the Ho Chi Minh Trail, 1966–1972 page 11
- ↑ Beech QU-22B
- ^ Paul Dickson: The electronic battlefield . Ed .: Bloomington, Indiana University Press. 1976, p. 136 ff . (English, archive.org ): “These early uses of ground sensors were effective and within a year John Mitchell's Justice Department was seeding a 65-mile experimental stretch of the border with Vietnam-tested acoustic sensors, buried strain-sensitive cables and infrared detection devices. "