109-839: The Beechcraft RC-12 Guardrail is an airborne signals intelligence (SIGINT) collection platform based on the Beechcraft King Air and Super King Air . While the US military and specifically the United States Army have numerous personnel transport variants of the King Air platforms referred to with the general C-12 designation, the RC-12 specification refers to a heavily modified platform that collects SIGINT through various sensors and onboard processors. The US Army Guardrail platform has been in service since 1971. Prior to
218-426: A central point, or perhaps to a distributed system in which all participate, such that the information can be correlated and a location computed. Modern SIGINT systems, therefore, have substantial communications among intercept platforms. Even if some platforms are clandestine, there is still a broadcast of information telling them where and how to look for signals. A United States targeting system under development in
327-426: A central point, or perhaps to a distributed system in which all participate, such that the information can be correlated and a location computed. Modern SIGINT systems, therefore, have substantial communications among intercept platforms. Even if some platforms are clandestine, there is still a broadcast of information telling them where and how to look for signals. A United States targeting system under development in
436-472: A confirmation, followed by observation of artillery fire, may identify an automated counterbattery fire system. A radio signal that triggers navigational beacons could be a radio landing aid for an airstrip or helicopter pad that is intended to be low-profile. Patterns do emerge. A radio signal with certain characteristics, originating from a fixed headquarters, may strongly suggest that a particular unit will soon move out of its regular base. The contents of
545-472: A confirmation, followed by observation of artillery fire, may identify an automated counterbattery fire system. A radio signal that triggers navigational beacons could be a radio landing aid for an airstrip or helicopter pad that is intended to be low-profile. Patterns do emerge. A radio signal with certain characteristics, originating from a fixed headquarters, may strongly suggest that a particular unit will soon move out of its regular base. The contents of
654-458: A different ECCM way to identify frequencies not being jammed or not in use. The earliest, and still common, means of direction finding is to use directional antennas as goniometers , so that a line can be drawn from the receiver through the position of the signal of interest. (See HF/DF .) Knowing the compass bearing, from a single point, to the transmitter does not locate it. Where the bearings from multiple points, using goniometry, are plotted on
763-458: A different ECCM way to identify frequencies not being jammed or not in use. The earliest, and still common, means of direction finding is to use directional antennas as goniometers , so that a line can be drawn from the receiver through the position of the signal of interest. (See HF/DF .) Knowing the compass bearing, from a single point, to the transmitter does not locate it. Where the bearings from multiple points, using goniometry, are plotted on
872-640: A lower level, German cryptanalysis, direction finding, and traffic analysis were vital to Rommel's early successes in the Western Desert Campaign until British forces tightened their communications discipline and Australian raiders destroyed his principle SIGINT Company. The United States Department of Defense has defined the term "signals intelligence" as: Being a broad field, SIGINT has many sub-disciplines. The two main ones are communications intelligence (COMINT) and electronic intelligence (ELINT). A collection system has to know to look for
981-565: A lower level, German cryptanalysis, direction finding, and traffic analysis were vital to Rommel's early successes in the Western Desert Campaign until British forces tightened their communications discipline and Australian raiders destroyed his principle SIGINT Company. The United States Department of Defense has defined the term "signals intelligence" as: Being a broad field, SIGINT has many sub-disciplines. The two main ones are communications intelligence (COMINT) and electronic intelligence (ELINT). A collection system has to know to look for
1090-407: A map, the transmitter will be located at the point where the bearings intersect. This is the simplest case; a target may try to confuse listeners by having multiple transmitters, giving the same signal from different locations, switching on and off in a pattern known to their user but apparently random to the listener. Individual directional antennas have to be manually or automatically turned to find
1199-407: A map, the transmitter will be located at the point where the bearings intersect. This is the simplest case; a target may try to confuse listeners by having multiple transmitters, giving the same signal from different locations, switching on and off in a pattern known to their user but apparently random to the listener. Individual directional antennas have to be manually or automatically turned to find
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#17327836526451308-509: A message written in the new ADFGVX cipher , which was cryptanalyzed by Georges Painvin . This gave the Allies advance warning of the German 1918 Spring Offensive . The British in particular, built up great expertise in the newly emerging field of signals intelligence and codebreaking (synonymous with cryptanalysis). On the declaration of war, Britain cut all German undersea cables. This forced
1417-648: A particular signal. "System", in this context, has several nuances. Targeting is the process of developing collection requirements : First, atmospheric conditions, sunspots , the target's transmission schedule and antenna characteristics, and other factors create uncertainty that a given signal intercept sensor will be able to "hear" the signal of interest, even with a geographically fixed target and an opponent making no attempt to evade interception. Basic countermeasures against interception include frequent changing of radio frequency , polarization , and other transmission characteristics. An intercept aircraft could not get off
1526-648: A particular signal. "System", in this context, has several nuances. Targeting is the process of developing collection requirements : First, atmospheric conditions, sunspots , the target's transmission schedule and antenna characteristics, and other factors create uncertainty that a given signal intercept sensor will be able to "hear" the signal of interest, even with a geographically fixed target and an opponent making no attempt to evade interception. Basic countermeasures against interception include frequent changing of radio frequency , polarization , and other transmission characteristics. An intercept aircraft could not get off
1635-515: A peace-time codebreaking agency should be created. The Government Code and Cypher School (GC&CS) was the first peace-time codebreaking agency, with a public function "to advise as to the security of codes and cyphers used by all Government departments and to assist in their provision", but also with a secret directive to "study the methods of cypher communications used by foreign powers". GC&CS officially formed on 1 November 1919, and produced its first decrypt on 19 October. By 1940, GC&CS
1744-523: A precise picture of the normal operation of the High Seas Fleet , to infer from the routes they chose where defensive minefields had been placed and where it was safe for ships to operate. Whenever a change to the normal pattern was seen, it immediately signalled that some operation was about to take place, and a warning could be given. Detailed information about submarine movements was also available. The use of radio-receiving equipment to pinpoint
1853-613: A prominent dorsal radome housing a satellite communications antenna. The RC-12 in various versions to include the newest RC-12X and RC-12X+ have seen deployments to Operation Enduring Freedom and Operation Iraqi Freedom . As of July 2012 , Northrop Grumman announced that its RC-12X Guardrails had completed over 1,000 missions since going into theatre in 2011. Recent upgrades and force realignments have seen these newest models replace older variants in Korea. A 2017 $ 462 million RC-12X program, by Northrop Grumman, will upgrade all aircraft in
1962-493: A public function "to advise as to the security of codes and cyphers used by all Government departments and to assist in their provision", but also with a secret directive to "study the methods of cypher communications used by foreign powers". GC&CS officially formed on 1 November 1919, and produced its first decrypt on 19 October. By 1940, GC&CS was working on the diplomatic codes and ciphers of 26 countries, tackling over 150 diplomatic cryptosystems. The US Cipher Bureau
2071-401: A radar is operating. Once the radar is known to be in the area, the next step is to find its location. If operators know the probable frequencies of transmissions of interest, they may use a set of receivers, preset to the frequencies of interest. These are the frequency (horizontal axis) versus power (vertical axis) produced at the transmitter, before any filtering of signals that do not add to
2180-401: A radar is operating. Once the radar is known to be in the area, the next step is to find its location. If operators know the probable frequencies of transmissions of interest, they may use a set of receivers, preset to the frequencies of interest. These are the frequency (horizontal axis) versus power (vertical axis) produced at the transmitter, before any filtering of signals that do not add to
2289-401: A safe distance from the user of the transmitter. When locations are known, usage patterns may emerge, from which inferences may be drawn. Traffic analysis is the discipline of drawing patterns from information flow among a set of senders and receivers, whether those senders and receivers are designated by location determined through direction finding , by addressee and sender identifications in
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#17327836526452398-401: A safe distance from the user of the transmitter. When locations are known, usage patterns may emerge, from which inferences may be drawn. Traffic analysis is the discipline of drawing patterns from information flow among a set of senders and receivers, whether those senders and receivers are designated by location determined through direction finding , by addressee and sender identifications in
2507-404: A sensor is unique. MASINT then becomes more informative, as individual transmitters and antennas may have unique side lobes, unintentional radiation, pulse timing, etc. Network build-up , or analysis of emitters (communication transmitters) in a target region over a sufficient period of time, enables creation of the communications flows of a battlefield. COMINT ( com munications int elligence)
2616-404: A sensor is unique. MASINT then becomes more informative, as individual transmitters and antennas may have unique side lobes, unintentional radiation, pulse timing, etc. Network build-up , or analysis of emitters (communication transmitters) in a target region over a sufficient period of time, enables creation of the communications flows of a battlefield. COMINT ( com munications int elligence)
2725-426: A tactical SIGINT requirement, whereas the larger aircraft tend to be assigned strategic/national missions. Before the detailed process of targeting begins, someone has to decide there is a value in collecting information about something. While it would be possible to direct signals intelligence collection at a major sports event, the systems would capture a great deal of noise, news signals, and perhaps announcements in
2834-426: A tactical SIGINT requirement, whereas the larger aircraft tend to be assigned strategic/national missions. Before the detailed process of targeting begins, someone has to decide there is a value in collecting information about something. While it would be possible to direct signals intelligence collection at a major sports event, the systems would capture a great deal of noise, news signals, and perhaps announcements in
2943-478: A tank battalion or tank-heavy task force. Another set of transmitters might identify the logistic net for that same unit. An inventory of ELINT sources might identify the medium - and long-range counter-artillery radars in a given area. Signals intelligence units will identify changes in the EOB, which might indicate enemy unit movement, changes in command relationships, and increases or decreases in capability. Using
3052-429: A tank battalion or tank-heavy task force. Another set of transmitters might identify the logistic net for that same unit. An inventory of ELINT sources might identify the medium - and long-range counter-artillery radars in a given area. Signals intelligence units will identify changes in the EOB, which might indicate enemy unit movement, changes in command relationships, and increases or decreases in capability. Using
3161-411: A vehicle. If these are regular reports over a period of time, they might reveal a patrol pattern. Direction-finding and radio frequency MASINT could help confirm that the traffic is not deception. The EOB buildup process is divided as following: Separation of the intercepted spectrum and the signals intercepted from each sensor must take place in an extremely small period of time, in order to separate
3270-411: A vehicle. If these are regular reports over a period of time, they might reveal a patrol pattern. Direction-finding and radio frequency MASINT could help confirm that the traffic is not deception. The EOB buildup process is divided as following: Separation of the intercepted spectrum and the signals intercepted from each sensor must take place in an extremely small period of time, in order to separate
3379-578: Is Amplitude comparison . An alternative to tunable directional antennas or large omnidirectional arrays such as the Wullenweber is to measure the time of arrival of the signal at multiple points, using GPS or a similar method to have precise time synchronization. Receivers can be on ground stations, ships, aircraft, or satellites, giving great flexibility. A more accurate approach is Interferometer. Modern anti-radiation missiles can home in on and attack transmitters; military antennas are rarely
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3488-518: Is Amplitude comparison . An alternative to tunable directional antennas or large omnidirectional arrays such as the Wullenweber is to measure the time of arrival of the signal at multiple points, using GPS or a similar method to have precise time synchronization. Receivers can be on ground stations, ships, aircraft, or satellites, giving great flexibility. A more accurate approach is Interferometer. Modern anti-radiation missiles can home in on and attack transmitters; military antennas are rarely
3597-417: Is a sub-category of signals intelligence that engages in dealing with messages or voice information derived from the interception of foreign communications. COMINT is commonly referred to as SIGINT, which can cause confusion when talking about the broader intelligence disciplines. The US Joint Chiefs of Staff defines it as "Technical information and intelligence derived from foreign communications by other than
3706-417: Is a sub-category of signals intelligence that engages in dealing with messages or voice information derived from the interception of foreign communications. COMINT is commonly referred to as SIGINT, which can cause confusion when talking about the broader intelligence disciplines. The US Joint Chiefs of Staff defines it as "Technical information and intelligence derived from foreign communications by other than
3815-415: Is acquired by a given country. Knowledge of physics and electronic engineering further narrows the problem of what types of equipment might be in use. An intelligence aircraft flying well outside the borders of another country will listen for long-range search radars, not short-range fire control radars that would be used by a mobile air defense. Soldiers scouting the front lines of another army know that
3924-415: Is acquired by a given country. Knowledge of physics and electronic engineering further narrows the problem of what types of equipment might be in use. An intelligence aircraft flying well outside the borders of another country will listen for long-range search radars, not short-range fire control radars that would be used by a mobile air defense. Soldiers scouting the front lines of another army know that
4033-543: Is in the general area of the signal. The owner of the transmitter can assume someone is listening, so might set up tank radios in an area where he wants the other side to believe he has actual tanks. As part of Operation Quicksilver , part of the deception plan for the invasion of Europe at the Battle of Normandy , radio transmissions simulated the headquarters and subordinate units of the fictitious First United States Army Group (FUSAG), commanded by George S. Patton , to make
4142-491: Is in the general area of the signal. The owner of the transmitter can assume someone is listening, so might set up tank radios in an area where he wants the other side to believe he has actual tanks. As part of Operation Quicksilver , part of the deception plan for the invasion of Europe at the Battle of Normandy , radio transmissions simulated the headquarters and subordinate units of the fictitious First United States Army Group (FUSAG), commanded by George S. Patton , to make
4251-433: Is the act and field of intelligence-gathering by interception of signals , whether communications between people ( communications intelligence —abbreviated to COMINT ) or from electronic signals not directly used in communication ( electronic intelligence —abbreviated to ELINT ). As classified and sensitive information is usually encrypted , signals intelligence may necessarily involve cryptanalysis (to decipher
4360-511: Is usually encrypted , signals intelligence may necessarily involve cryptanalysis (to decipher the messages). Traffic analysis —the study of who is signaling to whom and in what quantity—is also used to integrate information, and it may complement cryptanalysis. Electronic interceptions appeared as early as 1900, during the Boer War of 1899–1902. The British Royal Navy had installed wireless sets produced by Marconi on board their ships in
4469-510: The Admiralty ; Room 40 . An interception service known as 'Y' service , together with the post office and Marconi stations, grew rapidly to the point where the British could intercept almost all official German messages. The German fleet was in the habit each day of wirelessing the exact position of each ship and giving regular position reports when at sea. It was possible to build up
Beechcraft RC-12 Guardrail - Misplaced Pages Continue
4578-527: The Battle of Jutland as the British fleet was sent out to intercept them. The direction-finding capability allowed for the tracking and location of German ships, submarines, and Zeppelins . The system was so successful that by the end of the war, over 80 million words, comprising the totality of German wireless transmission over the course of the war, had been intercepted by the operators of the Y-stations and decrypted. However, its most astonishing success
4687-533: The North Sea . The battle of Dogger Bank was won in no small part due to the intercepts that allowed the Navy to position its ships in the right place. It played a vital role in subsequent naval clashes, including at the Battle of Jutland as the British fleet was sent out to intercept them. The direction-finding capability allowed for the tracking and location of German ships, submarines, and Zeppelins . The system
4796-610: The Russian Army ’s advance early in World War I and led to their disastrous defeat by the Germans under Ludendorff and Hindenburg at the Battle of Tannenberg . In 1918, French intercept personnel captured a message written in the new ADFGVX cipher , which was cryptanalyzed by Georges Painvin . This gave the Allies advance warning of the German 1918 Spring Offensive . The British in particular, built up great expertise in
4905-468: The post office and Marconi stations, grew rapidly to the point where the British could intercept almost all official German messages. The German fleet was in the habit each day of wirelessing the exact position of each ship and giving regular position reports when at sea. It was possible to build up a precise picture of the normal operation of the High Seas Fleet , to infer from the routes they chose where defensive minefields had been placed and where it
5014-848: The 3rd Military Intelligence Battalion at Camp Humphreys in Pyongtaek, South Korea. The next model was the RC-12K, after the RC-12H. The US Army ordered nine RC-12Ks in October 1985, of which eight replaced RC-12Ds in the 1st Military Intelligence Battalion in May 1991. One of these was lost in an accident. The ninth US Army aircraft was retained by the contractor, Raytheon, for conversion to the planned RC-12N configuration. An additional 2 RC-12K aircraft were delivered to Israel in May–June 1991. The prototype RC-12N
5123-837: The ATM Tasks for stalls, slow flight and VMC.' In February 1999, Commanding General, USAIC and FH, Major General John D. Thomas, sent a senior standardization instructor pilot and the 305th Military Intelligence Battalion Safety Officer to USAAVNC to review the RC-12K Accident Board findings to determine if training was a contributing factor. They recommended to Major General Thomas that the TC 1-219, Tasks for Slow Flight, Stalls and VMC , be rewritten. Data from operating manual General characteristics Performance Related development Related lists Signals intelligence Signals intelligence ( SIGINT )
5232-541: The Army's RC-12 fleet to the RC-12X standard, replacing or upgrading all older variants. The Guardrail Modernization program extends the life of the aircraft to 2025 and introduces new payloads to the system with enhanced capabilities. The program enhances the sustainability of the RC-12X through commonality, a new glass cockpit, structural upgrades, and significant hardware and software improvements. The newest Guardrail variant,
5341-549: The British forces in World War II came under the code name " Ultra ", managed from Government Code and Cypher School at Bletchley Park . Properly used, the German Enigma and Lorenz ciphers should have been virtually unbreakable, but flaws in German cryptographic procedures, and poor discipline among the personnel carrying them out, created vulnerabilities which made Bletchley's attacks feasible. Bletchley's work
5450-609: The British were the only people transmitting at the time, the British did not need special interpretation of the signals that they were. The birth of signals intelligence in a modern sense dates from the Russo-Japanese War of 1904–1905. As the Russian fleet prepared for conflict with Japan in 1904, the British ship HMS Diana stationed in the Suez Canal intercepted Russian naval wireless signals being sent out for
5559-548: The COMINT gathering method enables the intelligence officer to produce an electronic order of battle by traffic analysis and content analysis among several enemy units. For example, if the following messages were intercepted: This sequence shows that there are two units in the battlefield, unit 1 is mobile, while unit 2 is in a higher hierarchical level, perhaps a command post. One can also understand that unit 1 moved from one point to another which are distant from each 20 minutes with
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#17327836526455668-495: The COMINT gathering method enables the intelligence officer to produce an electronic order of battle by traffic analysis and content analysis among several enemy units. For example, if the following messages were intercepted: This sequence shows that there are two units in the battlefield, unit 1 is mobile, while unit 2 is in a higher hierarchical level, perhaps a command post. One can also understand that unit 1 moved from one point to another which are distant from each 20 minutes with
5777-438: The German defense think that the main invasion was to come at another location. In like manner, fake radio transmissions from Japanese aircraft carriers, before the Battle of Pearl Harbor , were made from Japanese local waters, while the attacking ships moved under strict radio silence. Traffic analysis need not focus on human communications. For example, a sequence of a radar signal, followed by an exchange of targeting data and
5886-438: The German defense think that the main invasion was to come at another location. In like manner, fake radio transmissions from Japanese aircraft carriers, before the Battle of Pearl Harbor , were made from Japanese local waters, while the attacking ships moved under strict radio silence. Traffic analysis need not focus on human communications. For example, a sequence of a radar signal, followed by an exchange of targeting data and
5995-404: The Germans to communicate exclusively via either (A) a telegraph line that connected through the British network and thus could be tapped; or (B) through radio which the British could then intercept. Rear Admiral Henry Oliver appointed Sir Alfred Ewing to establish an interception and decryption service at the Admiralty ; Room 40 . An interception service known as 'Y' service , together with
6104-518: The Guardrail Common Sensor (GR/CS), also called the RC-12X or RC-12X+, is a "fixed-wing, airborne, SIGINT-collection and precision targeting location system. It collects low-, mid- and high-band radio signals and ELINT signals, identifies and classifies them, determines source location, and provides near-real-time reporting. GR/CS uses a Guardrail Mission Operations Facility (MOF) for the control, data processing and message center for
6213-486: The Russian fleet prepared for conflict with Japan in 1904, the British ship HMS Diana stationed in the Suez Canal intercepted Russian naval wireless signals being sent out for the mobilization of the fleet, for the first time in history. Over the course of the First World War , a new method of signals intelligence reached maturity. Russia’s failure to properly protect its communications fatally compromised
6322-453: The actual information is at 800 kHz and 1.2 MHz. Real-world transmitters and receivers usually are directional. In the figure to the left, assume that each display is connected to a spectrum analyzer connected to a directional antenna aimed in the indicated direction. Spread-spectrum communications is an electronic counter-countermeasures (ECCM) technique to defeat looking for particular frequencies. Spectrum analysis can be used in
6431-453: The actual information is at 800 kHz and 1.2 MHz. Real-world transmitters and receivers usually are directional. In the figure to the left, assume that each display is connected to a spectrum analyzer connected to a directional antenna aimed in the indicated direction. Spread-spectrum communications is an electronic counter-countermeasures (ECCM) technique to defeat looking for particular frequencies. Spectrum analysis can be used in
6540-645: The army in France in 1915. By May 1915, the Admiralty was able to track German submarines crossing the North Sea. Some of these stations also acted as 'Y' stations to collect German messages, but a new section was created within Room 40 to plot the positions of ships from the directional reports. Room 40 played an important role in several naval engagements during the war, notably in detecting major German sorties into
6649-506: The broader organizational order of battle . EOB covers both COMINT and ELINT. The Defense Intelligence Agency maintains an EOB by location. The Joint Spectrum Center (JSC) of the Defense Information Systems Agency supplements this location database with five more technical databases: For example, several voice transmitters might be identified as the command net (i.e., top commander and direct reports) in
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#17327836526456758-416: The broader organizational order of battle . EOB covers both COMINT and ELINT. The Defense Intelligence Agency maintains an EOB by location. The Joint Spectrum Center (JSC) of the Defense Information Systems Agency supplements this location database with five more technical databases: For example, several voice transmitters might be identified as the command net (i.e., top commander and direct reports) in
6867-446: The decision to target is made, the various interception points need to cooperate, since resources are limited. Knowing what interception equipment to use becomes easier when a target country buys its radars and radios from known manufacturers, or is given them as military aid . National intelligence services keep libraries of devices manufactured by their own country and others, and then use a variety of techniques to learn what equipment
6976-446: The decision to target is made, the various interception points need to cooperate, since resources are limited. Knowing what interception equipment to use becomes easier when a target country buys its radars and radios from known manufacturers, or is given them as military aid . National intelligence services keep libraries of devices manufactured by their own country and others, and then use a variety of techniques to learn what equipment
7085-469: The different signals to different transmitters in the battlefield. The complexity of the separation process depends on the complexity of the transmission methods (e.g., hopping or time-division multiple access (TDMA)). By gathering and clustering data from each sensor, the measurements of the direction of signals can be optimized and get much more accurate than the basic measurements of a standard direction finding sensor. By calculating larger samples of
7194-469: The different signals to different transmitters in the battlefield. The complexity of the separation process depends on the complexity of the transmission methods (e.g., hopping or time-division multiple access (TDMA)). By gathering and clustering data from each sensor, the measurements of the direction of signals can be optimized and get much more accurate than the basic measurements of a standard direction finding sensor. By calculating larger samples of
7303-714: The early 1980s, the early Guardrail variants were based on the U-21 . After adopting the C-12 platform over the U-21, the Guardrail platform has received structural, power plant, and equipment upgrades as noted by the various models described below. Initially, the US Army had 13 RC-12Ds converted from C-12Ds , with deliveries starting in mid-1983. One aircraft was assigned to US Army Forces Command (FORSCOM) at Fort McPherson , Georgia, and
7412-512: The fronts, that we won the war!" Supreme Allied Commander, Dwight D. Eisenhower , at the end of the war, described Ultra as having been "decisive" to Allied victory. Official historian of British Intelligence in World War II Sir Harry Hinsley argued that Ultra shortened the war "by not less than two years and probably by four years"; and that, in the absence of Ultra, it is uncertain how the war would have ended. At
7521-427: The fronts, that we won the war!" Supreme Allied Commander, Dwight D. Eisenhower , at the end of the war, described Ultra as having been "decisive" to Allied victory. Official historian of British Intelligence in World War II Sir Harry Hinsley argued that Ultra shortened the war "by not less than two years and probably by four years"; and that, in the absence of Ultra, it is uncertain how the war would have ended. At
7630-420: The ground if it had to carry antennas and receivers for every possible frequency and signal type to deal with such countermeasures. Second, locating the transmitter's position is usually part of SIGINT. Triangulation and more sophisticated radio location techniques, such as time of arrival methods, require multiple receiving points at different locations. These receivers send location-relevant information to
7739-420: The ground if it had to carry antennas and receivers for every possible frequency and signal type to deal with such countermeasures. Second, locating the transmitter's position is usually part of SIGINT. Triangulation and more sophisticated radio location techniques, such as time of arrival methods, require multiple receiving points at different locations. These receivers send location-relevant information to
7848-500: The importance of interception and decryption firmly established by the wartime experience, countries established permanent agencies dedicated to this task in the interwar period. In 1919, the British Cabinet's Secret Service Committee, chaired by Lord Curzon , recommended that a peace-time codebreaking agency should be created. The Government Code and Cypher School (GC&CS) was the first peace-time codebreaking agency, with
7957-448: The information being transmitted. Received energy on a particular frequency may start a recorder, and alert a human to listen to the signals if they are intelligible (i.e., COMINT). If the frequency is not known, the operators may look for power on primary or sideband frequencies using a spectrum analyzer . Information from the spectrum analyzer is then used to tune receivers to signals of interest. For example, in this simplified spectrum,
8066-448: The information being transmitted. Received energy on a particular frequency may start a recorder, and alert a human to listen to the signals if they are intelligible (i.e., COMINT). If the frequency is not known, the operators may look for power on primary or sideband frequencies using a spectrum analyzer . Information from the spectrum analyzer is then used to tune receivers to signals of interest. For example, in this simplified spectrum,
8175-412: The intended recipients". ELINT Signals intelligence ( SIGINT ) is the act and field of intelligence-gathering by interception of signals , whether communications between people ( communications intelligence —abbreviated to COMINT ) or from electronic signals not directly used in communication ( electronic intelligence —abbreviated to ELINT ). As classified and sensitive information
8284-473: The late 1890s, and the British Army used some limited wireless signalling. The Boers captured some wireless sets and used them to make vital transmissions. Since the British were the only people transmitting at the time, the British did not need special interpretation of the signals that they were. The birth of signals intelligence in a modern sense dates from the Russo-Japanese War of 1904–1905. As
8393-541: The late 1990s, PSTS, constantly sends out information that helps the interceptors properly aim their antennas and tune their receivers. Larger intercept aircraft, such as the EP-3 or RC-135 , have the on-board capability to do some target analysis and planning, but others, such as the RC-12 GUARDRAIL , are completely under ground direction. GUARDRAIL aircraft are fairly small and usually work in units of three to cover
8502-427: The late 1990s, PSTS, constantly sends out information that helps the interceptors properly aim their antennas and tune their receivers. Larger intercept aircraft, such as the EP-3 or RC-135 , have the on-board capability to do some target analysis and planning, but others, such as the RC-12 GUARDRAIL , are completely under ground direction. GUARDRAIL aircraft are fairly small and usually work in units of three to cover
8611-407: The location of any single transmitter was also developed during the war. Captain H.J. Round , working for Marconi , began carrying out experiments with direction-finding radio equipment for the army in France in 1915. By May 1915, the Admiralty was able to track German submarines crossing the North Sea. Some of these stations also acted as 'Y' stations to collect German messages, but a new section
8720-564: The message need not be known to infer the movement. There is an art as well as science of traffic analysis. Expert analysts develop a sense for what is real and what is deceptive. Harry Kidder , for example, was one of the star cryptanalysts of World War II, a star hidden behind the secret curtain of SIGINT. Generating an electronic order of battle (EOB) requires identifying SIGINT emitters in an area of interest, determining their geographic location or range of mobility, characterizing their signals, and, where possible, determining their role in
8829-564: The message need not be known to infer the movement. There is an art as well as science of traffic analysis. Expert analysts develop a sense for what is real and what is deceptive. Harry Kidder , for example, was one of the star cryptanalysts of World War II, a star hidden behind the secret curtain of SIGINT. Generating an electronic order of battle (EOB) requires identifying SIGINT emitters in an area of interest, determining their geographic location or range of mobility, characterizing their signals, and, where possible, determining their role in
8938-410: The message, or even MASINT techniques for "fingerprinting" transmitters or operators. Message content other than the sender and receiver is not necessary to do traffic analysis, although more information can be helpful. For example, if a certain type of radio is known to be used only by tank units, even if the position is not precisely determined by direction finding, it may be assumed that a tank unit
9047-410: The message, or even MASINT techniques for "fingerprinting" transmitters or operators. Message content other than the sender and receiver is not necessary to do traffic analysis, although more information can be helpful. For example, if a certain type of radio is known to be used only by tank units, even if the position is not precisely determined by direction finding, it may be assumed that a tank unit
9156-526: The messages). Traffic analysis —the study of who is signaling to whom and in what quantity—is also used to integrate information, and it may complement cryptanalysis. Electronic interceptions appeared as early as 1900, during the Boer War of 1899–1902. The British Royal Navy had installed wireless sets produced by Marconi on board their ships in the late 1890s, and the British Army used some limited wireless signalling. The Boers captured some wireless sets and used them to make vital transmissions. Since
9265-453: The mobilization of the fleet, for the first time in history. Over the course of the First World War , a new method of signals intelligence reached maturity. Russia’s failure to properly protect its communications fatally compromised the Russian Army ’s advance early in World War I and led to their disastrous defeat by the Germans under Ludendorff and Hindenburg at the Battle of Tannenberg . In 1918, French intercept personnel captured
9374-492: The newly emerging field of signals intelligence and codebreaking (synonymous with cryptanalysis). On the declaration of war, Britain cut all German undersea cables. This forced the Germans to communicate exclusively via either (A) a telegraph line that connected through the British network and thus could be tapped; or (B) through radio which the British could then intercept. Rear Admiral Henry Oliver appointed Sir Alfred Ewing to establish an interception and decryption service at
9483-461: The other side will be using radios that must be portable and not have huge antennas. Even if a signal is human communications (e.g., a radio), the intelligence collection specialists have to know it exists. If the targeting function described above learns that a country has a radar that operates in a certain frequency range, the first step is to use a sensitive receiver, with one or more antennas that listen in every direction, to find an area where such
9592-461: The other side will be using radios that must be portable and not have huge antennas. Even if a signal is human communications (e.g., a radio), the intelligence collection specialists have to know it exists. If the targeting function described above learns that a country has a radar that operates in a certain frequency range, the first step is to use a sensitive receiver, with one or more antennas that listen in every direction, to find an area where such
9701-441: The remainder to the 1st Military Intelligence Battalion at Wiesbaden, Germany, and the 2nd Military Intelligence Battalion at Stuttgart, Germany. The German-based aircraft were re-assigned in late 1991 to 3rd, 15th and 304th Military Intelligence Battalions at Camp Humphreys (South Korea), Fort Hood (Texas) and Fort Huachuca (Arizona) respectively. One was converted back to an earlier configuration as C-12D-1. The next model
9810-417: The sensor's output data in near real-time, together with historical information of signals, better results are achieved. Data fusion correlates data samples from different frequencies from the same sensor, "same" being confirmed by direction finding or radiofrequency MASINT. If an emitter is mobile, direction finding, other than discovering a repetitive pattern of movement, is of limited value in determining if
9919-417: The sensor's output data in near real-time, together with historical information of signals, better results are achieved. Data fusion correlates data samples from different frequencies from the same sensor, "same" being confirmed by direction finding or radiofrequency MASINT. If an emitter is mobile, direction finding, other than discovering a repetitive pattern of movement, is of limited value in determining if
10028-509: The signal direction, which may be too slow when the signal is of short duration. One alternative is the Wullenweber array technique. In this method, several concentric rings of antenna elements simultaneously receive the signal, so that the best bearing will ideally be clearly on a single antenna or a small set. Wullenweber arrays for high-frequency signals are enormous, referred to as "elephant cages" by their users. A more advance approach
10137-450: The signal direction, which may be too slow when the signal is of short duration. One alternative is the Wullenweber array technique. In this method, several concentric rings of antenna elements simultaneously receive the signal, so that the best bearing will ideally be clearly on a single antenna or a small set. Wullenweber arrays for high-frequency signals are enormous, referred to as "elephant cages" by their users. A more advance approach
10246-451: The stadium. If, however, an anti-terrorist organization believed that a small group would be trying to coordinate their efforts using short-range unlicensed radios at the event, SIGINT targeting of radios of that type would be reasonable. Targeting would not know where in the stadium the radios might be located or the exact frequency they are using; those are the functions of subsequent steps such as signal detection and direction finding. Once
10355-451: The stadium. If, however, an anti-terrorist organization believed that a small group would be trying to coordinate their efforts using short-range unlicensed radios at the event, SIGINT targeting of radios of that type would be reasonable. Targeting would not know where in the stadium the radios might be located or the exact frequency they are using; those are the functions of subsequent steps such as signal detection and direction finding. Once
10464-509: The story of Operation SALAM , László Almásy 's mission across the desert behind Allied lines in 1942. Prior to the Normandy landings on D-Day in June 1944, the Allies knew the locations of all but two of Germany's fifty-eight Western Front divisions. Winston Churchill was reported to have told King George VI : "It is thanks to the secret weapon of General Menzies , put into use on all
10573-403: The story of Operation SALAM , László Almásy 's mission across the desert behind Allied lines in 1942. Prior to the Normandy landings on D-Day in June 1944, the Allies knew the locations of all but two of Germany's fifty-eight Western Front divisions. Winston Churchill was reported to have told King George VI : "It is thanks to the secret weapon of General Menzies , put into use on all
10682-524: The system.” On 16 April 1997, the 224th Military Intelligence Battalion lost an RC-12N and 2 crew members in a fatal training accident. The following year on 6 November 1998, the 1st Military Intelligence Battalion lost a RC-12K and 2 crew members in a similar training accident. In both accidents, the United States Army Safety Center Accident Boards listed in their recommendations to TRADOC to 'Re-evaluate
10791-438: The whole of the British forces in World War II came under the code name " Ultra ", managed from Government Code and Cypher School at Bletchley Park . Properly used, the German Enigma and Lorenz ciphers should have been virtually unbreakable, but flaws in German cryptographic procedures, and poor discipline among the personnel carrying them out, created vulnerabilities which made Bletchley's attacks feasible. Bletchley's work
10900-723: Was converted from an RC-12K. A total of 15 were converted by E-Systems and delivered 1992-93 to the 224th Military Intelligence Battalion at Hunter Army Airfield , Georgia and the 304th Military Intelligence Battalion at Libby Army Airfield, Fort Huachuca, Arizona. One of these was lost in accident. These led to the next model, the RC-12P. A total of 9 RC-12P aircraft were delivered to ESL/TRW at Moffett Federal Airfield in late 1994 and 1995. These airframes remained there in 1999. Three RC-12Ps were then modified by Raytheon and TRW to become RC-12Q. They were transferred to TRW in 1996 for outfitting, where they remained in 1999. The aircraft featured
11009-437: Was created within Room 40 to plot the positions of ships from the directional reports. Room 40 played an important role in several naval engagements during the war, notably in detecting major German sorties into the North Sea . The battle of Dogger Bank was won in no small part due to the intercepts that allowed the Navy to position its ships in the right place. It played a vital role in subsequent naval clashes, including at
11118-686: Was essential to defeating the U-boats in the Battle of the Atlantic , and to the British naval victories in the Battle of Cape Matapan and the Battle of North Cape . In 1941, Ultra exerted a powerful effect on the North African desert campaign against German forces under General Erwin Rommel . General Sir Claude Auchinleck wrote that were it not for Ultra, "Rommel would have certainly got through to Cairo". Ultra decrypts featured prominently in
11227-461: Was essential to defeating the U-boats in the Battle of the Atlantic , and to the British naval victories in the Battle of Cape Matapan and the Battle of North Cape . In 1941, Ultra exerted a powerful effect on the North African desert campaign against German forces under General Erwin Rommel . General Sir Claude Auchinleck wrote that were it not for Ultra, "Rommel would have certainly got through to Cairo". Ultra decrypts featured prominently in
11336-558: Was established in 1919 and achieved some success at the Washington Naval Conference in 1921, through cryptanalysis by Herbert Yardley . Secretary of War Henry L. Stimson closed the US Cipher Bureau in 1929 with the words "Gentlemen do not read each other's mail." The use of SIGINT had even greater implications during World War II . The combined effort of intercepts and cryptanalysis for the whole of
11445-647: Was in decrypting the Zimmermann Telegram , a telegram from the German Foreign Office sent via Washington to its ambassador Heinrich von Eckardt in Mexico. With the importance of interception and decryption firmly established by the wartime experience, countries established permanent agencies dedicated to this task in the interwar period. In 1919, the British Cabinet's Secret Service Committee, chaired by Lord Curzon , recommended that
11554-494: Was safe for ships to operate. Whenever a change to the normal pattern was seen, it immediately signalled that some operation was about to take place, and a warning could be given. Detailed information about submarine movements was also available. The use of radio-receiving equipment to pinpoint the location of any single transmitter was also developed during the war. Captain H.J. Round , working for Marconi , began carrying out experiments with direction-finding radio equipment for
11663-436: Was so successful that by the end of the war, over 80 million words, comprising the totality of German wireless transmission over the course of the war, had been intercepted by the operators of the Y-stations and decrypted. However, its most astonishing success was in decrypting the Zimmermann Telegram , a telegram from the German Foreign Office sent via Washington to its ambassador Heinrich von Eckardt in Mexico. With
11772-576: Was the RC-12G. Three RC-12G were delivered in 1985 after conversion from C-12D airframes. These aircraft served in Latin America and then with the 138th Military Intelligence Company (Aerial Exploitation) in Orlando, Florida, before being moved into storage at Fort Sill , Oklahoma. After the RC-12G, the next model was the RC-12H. The initial system contractor ESL Inc. delivered 6 RC-12H in 1988 for
11881-533: Was working on the diplomatic codes and ciphers of 26 countries, tackling over 150 diplomatic cryptosystems. The US Cipher Bureau was established in 1919 and achieved some success at the Washington Naval Conference in 1921, through cryptanalysis by Herbert Yardley . Secretary of War Henry L. Stimson closed the US Cipher Bureau in 1929 with the words "Gentlemen do not read each other's mail." The use of SIGINT had even greater implications during World War II . The combined effort of intercepts and cryptanalysis for
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