108-465: 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 is usually encrypted , signals intelligence may necessarily involve cryptanalysis (to decipher
216-571: A Tuath . The North Sea has provided waterway access for commerce and conquest. Many areas have access to the North Sea because of its long coastline and the European rivers that empty it. There is little documentary evidence concerning the North Sea before the Roman conquest of Britain in 43 CE, however, archaeological evidence reveals the diffusion of cultures and technologies from across or along
324-425: 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
432-738: A challenge to their dominance of the North Sea until the 20th century. Tensions in the North Sea were again heightened in 1904 by the Dogger Bank incident . During the Russo-Japanese War , several ships of the Russian Baltic Fleet, which was on its way to the Far East, mistook British fishing boats for Japanese ships and fired on them, and then upon each other, near the Dogger Bank, nearly causing Britain to enter
540-472: 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
648-458: 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
756-639: 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
864-407: 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
972-580: A maximum depth of 725 metres (2,379 ft). The Dogger Bank , a vast moraine , or accumulation of unconsolidated glacial debris, rises to a mere 15 to 30 m (50 to 100 ft) below the surface. This feature has produced the finest fishing location of the North Sea. The Long Forties and the Broad Fourteens are large areas with roughly uniform depth in fathoms (forty fathoms and fourteen fathoms or 73 and 26 m or 240 and 85 ft deep, respectively). These great banks and others make
1080-508: 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
1188-648: 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
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#17327905707871296-489: 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
1404-401: 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
1512-401: 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
1620-403: 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)
1728-426: 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
1836-478: 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
1944-717: A vast merchant marine, a large fishing fleet, powerful navy, and sophisticated financial markets made the Dutch the ascendant power in the North Sea, to be challenged by an ambitious England. This rivalry led to the first three Anglo-Dutch Wars between 1652 and 1673, which ended with Dutch victories. After the Glorious Revolution in 1688, the Dutch prince William ascended to the English throne. With unified leadership, commercial, military, and political power began to shift from Amsterdam to London. The British did not face
2052-411: 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
2160-578: 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
2268-620: Is 17 °C (63 °F) in the summer and 6 °C (43 °F) in the winter. The average temperatures have been trending higher since 1988, which has been attributed to climate change . Air temperatures in January range on average between 0 and 4 °C (32 and 39 °F) and in July between 13 and 18 °C (55 and 64 °F). The winter months see frequent gales and storms. The salinity averages between 34 and 35 grams per litre (129 and 132 g/US gal) of water. The salinity has
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#17327905707872376-417: 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
2484-415: 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
2592-526: Is also home to marine mammals. Common seals , grey seals , and harbour porpoises can be found along the coasts, at marine installations, and on islands. The very northern North Sea islands such as the Shetland Islands are occasionally home to a larger variety of pinnipeds including bearded , harp , hooded and ringed seals , and even walrus . North Sea cetaceans include various porpoise , dolphin and whale species. Plant species in
2700-543: 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
2808-699: Is recorded to have killed more than 100,000 people. In 1362, the Second Marcellus Flood , also known as the Grote Manndrenke , hit the entire southern coast of the North Sea. Chronicles of the time again record more than 100,000 deaths, large parts of the coast were lost permanently to the sea, including the now legendary lost city of Rungholt . In the 20th century, the North Sea flood of 1953 flooded several nations' coasts and cost more than 2,000 lives. 315 citizens of Hamburg died in
2916-463: Is usually confused with their brother agency MI5, which focuses on the security of Britain. Financial intelligence (FININT) are gathered from analysis of monetary transactions. Geospatial intelligence (GEOINT) are gathered from satellite and aerial photography, or mapping/terrain data. Measurement and signature intelligence (MASINT) are gathered from an array of signatures (distinctive characteristics) of fixed or dynamic target sources. According to
3024-689: The Air Force Institute of Technology 's Center for MASINT Studies and Research, MASINT is split into six major disciplines: electro-optical, nuclear, radar, geophysical, materials, and radiofrequency. Open-source intelligence (OSINT) are gathered from open sources. OSINT can be further segmented by the source type: Internet/General, Scientific/Technical, and various HUMINT specialties, e.g. trade shows, association meetings, and interviews. Signals intelligence (SIGINT) are gathered from interception of signals. Technical intelligence (TECHINT) are gathered from analysis of weapons and equipment used by
3132-473: The Battle of Heligoland Bight , the Battle of the Dogger Bank , and the Battle of Jutland . World War I also brought the first extensive use of submarine warfare , and a number of submarine actions occurred in the North Sea. The Second World War also saw action in the North Sea, though it was restricted more to aircraft reconnaissance and action by fighter/bomber aircraft, submarines and smaller vessels such as minesweepers and torpedo boats . After
3240-592: The English Channel was triggered by the earthquake, which in turn caused a tsunami. The tsunami triggered by the 1755 Lisbon earthquake reached Holland, although the waves had lost their destructive power. The largest earthquake ever recorded in the United Kingdom was the 1931 Dogger Bank earthquake , which measured 6.1 on the Richter magnitude scale and caused a small tsunami that flooded parts of
3348-684: The Frisian Islands . The North Sea receives freshwater from a number of European continental watersheds, as well as the British Isles . A large part of the European drainage basin empties into the North Sea, including water from the Baltic Sea . The largest and most important rivers flowing into the North Sea are the Elbe and the Rhine – Meuse . Around 185 million people live in
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3456-517: The Last Glacial Maximum when the sea began to flood the European continental shelf. In 2006 a bone fragment was found while drilling for oil in the North Sea. Analysis indicated that it was a Plateosaurus from 199 to 216 million years ago. This was the deepest dinosaur fossil ever found and the first find for Norway. Copepods and other zooplankton are plentiful in the North Sea. These tiny organisms are crucial elements of
3564-965: The Latin names Mare Germanicum and Oceanus Germanicus , and these persisted in use until the First World War. Other common names in use for long periods were the Latin terms Mare Frisicum , as well as the English equivalent, "Frisian Sea". The modern names of the sea in the other local languages are: Danish : Vesterhavet , lit. 'West Sea' [ˈvestɐˌhɛˀvð̩] or Nordsøen [ˈnoɐ̯ˌsøˀn̩] , Dutch : Noordzee , Dutch Low Saxon : Noordzee , French : Mer du Nord , West Frisian : Noardsee , German : Nordsee , Low German : Noordsee , North Frisian : Weestsiie , lit. 'West Sea', Swedish : Nordsjön , Bokmål : Nordsjøen [ˈnûːrˌʂøːn] , Nynorsk : Nordsjøen , Scots : North Sea and Scottish Gaelic : An Cuan
3672-531: 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
3780-529: The North Sea flood of 1962 . Though rare, the North Sea has been the site of a number of historically documented tsunamis . The Storegga Slides were a series of underwater landslides, in which a piece of the Norwegian continental shelf slid into the Norwegian Sea. The immense landslips occurred between 8150 BCE and 6000 BCE, and caused a tsunami up to 20 metres (66 ft) high that swept through
3888-879: The Shetland Islands). On the North. From the North point (Fethaland Point) of the Mainland of the Shetland Islands, across to Graveland Ness (60°39'N) in the Island of Yell , through Yell to Gloup Ness (1°04'W) and across to Spoo Ness (60°45'N) in Unst island, through Unst to Herma Ness (60°51'N), on to the SW point of the Rumblings and to Muckle Flugga ( 60°51′N 0°53′W / 60.850°N 0.883°W / 60.850; -0.883 ) all these being included in
3996-496: The catchment area of the rivers discharging into the North Sea encompassing some highly industrialized areas. For the most part, the sea lies on the European continental shelf with a mean depth of 90 metres (300 ft). The only exception is the Norwegian trench , which extends parallel to the Norwegian shoreline from Oslo to an area north of Bergen . It is between 20 and 30 kilometres (12 and 19 mi) wide and has
4104-463: The food chain supporting many species of fish. Over 230 species of fish live in the North Sea. Cod , haddock , whiting , saithe , plaice , sole , mackerel , herring , pouting , sprat , and sandeel are all very common and are fished commercially. Due to the various depths of the North Sea trenches and differences in salinity, temperature, and water movement, some fish such as blue-mouth redfish and rabbitfish reside only in small areas of
4212-535: The littoral is low and marshy. The east coast and south-east of the North Sea ( Wadden Sea ) have coastlines that are mainly sandy and straight owing to longshore drift , particularly along Belgium and Denmark. The southern coastal areas were originally flood plains and swampy land. In areas especially vulnerable to storm surges, people settled behind elevated levees and on natural areas of high ground such as spits and geestland . As early as 500 BC, people were constructing artificial dwelling hills higher than
4320-531: 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
4428-741: The 13th century the Hanseatic League , though centred on the Baltic Sea , started to control most of the trade through important members and outposts on the North Sea. The League lost its dominance in the 16th century, as neighbouring states took control of former Hanseatic cities and outposts. Their internal conflict prevented effective cooperation and defence. As the League lost control of its maritime cities, new trade routes emerged that provided Europe with Asian, American, and African goods. The 17th century Dutch Golden Age saw Dutch maritime power at its zenith. Important overseas colonies,
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4536-592: The British coast. Shallow epicontinental seas like the current North Sea have since long existed on the European continental shelf . The rifting that formed the northern part of the Atlantic Ocean during the Jurassic and Cretaceous periods, from about 150 million years ago , caused tectonic uplift in the British Isles. Since then, a shallow sea has almost continuously existed between
4644-549: 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
4752-540: 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
4860-548: 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
4968-438: 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
5076-513: 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
5184-568: The Middle Ages through the 15th century, the northern European coastal ports exported domestic goods, dyes, linen, salt, metal goods and wine. The Scandinavian and Baltic areas shipped grain, fish, naval necessities, and timber. In turn, the North Sea countries imported high-grade cloths, spices, and fruits from the Mediterranean region. Commerce during this era was mainly conducted by maritime trade due to underdeveloped roadways. In
5292-588: The Middle Ages to the modern era. It was also important globally through the power northern Europeans projected worldwide during much of the Middle Ages and into the modern era. The North Sea was the centre of the Vikings' rise . The Hanseatic League , the Dutch Republic , and the British each sought to gain command of the North Sea and access to the world's markets and resources. As Germany's only outlet to
5400-486: The Netherlands. The North Sea Floods of 1953 and 1962 were the impetus for further raising of the dikes as well as the shortening of the coast line so as to present as little surface area as possible to the punishment of the sea and the storms. Currently, 27% of the Netherlands is below sea level protected by dikes, dunes, and beach flats. Coastal management today consists of several levels. The dike slope reduces
5508-926: The North Sea are home to nature reserves including the Ythan Estuary , Fowlsheugh Nature Preserve, and Farne Islands in the UK and the Wadden Sea National Parks in Denmark, Germany and the Netherlands. These locations provide breeding habitat for dozens of bird species. Tens of millions of birds make use of the North Sea for breeding, feeding, or migratory stopovers every year. Populations of black-legged kittiwakes , Atlantic puffins , northern gannets , northern fulmars , and species of petrels , seaducks , loons (divers), cormorants , gulls , auks , and terns , and many other seabirds make these coasts popular for birdwatching . The North Sea
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#17327905707875616-674: The North Sea area; thence up the meridian of 0°53' West to the parallel of 61°00' North and eastward along this parallel to the coast of Norway, the whole of Viking Bank is thus included in the North Sea. On the East. The Western limit of the Skagerrak [A line joining Hanstholm ( 57°07′N 8°36′E / 57.117°N 8.600°E / 57.117; 8.600 ) and the Naze ( Lindesnes , 58°N 7°E / 58°N 7°E / 58; 7 )]. The average temperature
5724-523: The North Sea during the Migration Period . They made successive invasions of the island from what is now the Netherlands, Denmark, and Germany. The Viking Age began in 793 with the attack on Lindisfarne ; for the next quarter-millennium, the Vikings ruled the North Sea. In their superior longships , they raided, traded, and established colonies and outposts along the coasts of the sea. From
5832-613: The North Sea include species of wrack , among them bladder wrack , knotted wrack , and serrated wrack. Algae , macroalgal, and kelp , such as oarweed and laminaria hyperboria, and species of maerl are found as well. Eelgrass , formerly common in the entirety of the Wadden Sea, was nearly wiped out in the 20th century by a disease. Similarly, sea grass used to coat huge tracts of ocean floor, but have been damaged by trawling and dredging have diminished its habitat and prevented its return. Invasive Japanese seaweed has spread along
5940-559: The North Sea particularly hazardous to navigate, which has been alleviated by the implementation of satellite navigation systems . The Devil's Hole lies 320 kilometres (200 mi) east of Dundee , Scotland. The feature is a series of asymmetrical trenches between 20 and 30 kilometres (12 and 19 mi) long, one and two kilometres (0.6 and 1.2 mi) wide and up to 230 metres (750 ft) deep. Other areas which are less deep are Cleaver Bank , Fisher Bank and Noordhinder Bank . The International Hydrographic Organization defines
6048-500: The North Sea to Great Britain and Scandinavia and reliance by some prehistoric cultures on fishing, whaling, and seaborne trade on the North Sea. The Romans established organised ports in Britain, which increased shipping and began sustained trade the diffusion of cultures and technologies from across or along the North Sea to Great Britain and Scandinavia and reliance by some prehistoric cultures on fishing, whaling, and seaborne trade on
6156-416: The North Sea until the 20th century, when numbers declined due to overfishing . Other factors like the introduction of non-indigenous species , industrial and agricultural pollution , trawling and dredging , human-induced eutrophication , construction on coastal breeding and feeding grounds, sand and gravel extraction, offshore construction , and heavy shipping traffic have also contributed to
6264-590: The North Sea, having the greatest effect on Scotland and the Faeroe Islands . The Dover Straits earthquake of 1580 is among the first recorded earthquakes in the North Sea measuring between 5.6 and 5.9 on the Richter scale. This event caused extensive damage in Calais both through its tremors and possibly triggered a tsunami , though this has never been confirmed. The theory is a vast underwater landslide in
6372-453: The North Sea. Crustaceans are also commonly found throughout the sea. Norway lobster , deep-water prawns , and brown shrimp are all commercially fished, but other species of lobster , shrimp , oyster , mussels and clams all live in the North Sea. Recently non-indigenous species have become established including the Pacific oyster and Atlantic jackknife clam . The coasts of
6480-517: The North Sea. The Romans established organised ports in Britain, which increased shipping and began sustained trade and many Scandinavian tribes participated in raids and wars against the Romans and Roman coinage and manufacturing were important trade goods. When the Romans abandoned Britain in 410, the Germanic Angles , Frisians , Saxons , and Jutes began the next great migration across
6588-500: The North Sea. The wave continues to travel northward in the Atlantic Ocean, and once past the northern tip of Great Britain, the Kelvin wave turns east and south and once again enters the North Sea. The eastern and western coasts of the North Sea are jagged, formed by glaciers during the ice ages . The coastlines along the southernmost part are covered with the remains of deposited glacial sediment. The Norwegian mountains plunge into
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#17327905707876696-558: The Orkney Islands through the mid-16th century, as both Sable Island and Orkney Islands lay within their normal range. Grey whales also resided in the North Sea but were driven to extinction in the Atlantic in the 17th century Other species have dramatically declined in population, though they are still found. North Atlantic right whales , sturgeon , shad , rays , skates , salmon , and other species were common in
6804-453: 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
6912-640: The armed forces of foreign nations, or environmental conditions. North Sea Download coordinates as: The North Sea lies between Great Britain , Denmark , Norway , Germany , the Netherlands , Belgium and France . An epeiric sea on the European continental shelf , it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian Sea in
7020-587: 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
7128-505: 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
7236-551: The coasts of the Netherlands, Belgium, Germany, and Denmark and low-lying areas of eastern England particularly around The Wash and Fens . Storm surges are caused by changes in barometric pressure combined with strong wind created wave action . The first recorded storm tide flood was the Julianenflut , on 17 February 1164. In its wake, the Jadebusen , (a bay on the coast of Germany), began to form. A storm tide in 1228
7344-446: 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
7452-586: The decline. For example, a resident orca pod was lost in the 1960s, presumably due to the peak in PCB pollution in this time period. The OSPAR commission manages the OSPAR convention to counteract the harmful effects of human activity on wildlife in the North Sea, preserve endangered species , and provide environmental protection. All North Sea border states are signatories of the MARPOL 73/78 Accords, which preserve
7560-468: 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
7668-555: The energy of the incoming sea, so that the dike itself does not receive the full impact. Dikes that lie directly on the sea are especially reinforced. The dikes have, over the years, been repeatedly raised, sometimes up to 9 metres (30 ft) and have been made flatter to better reduce wave erosion. Where the dunes are sufficient to protect the land behind them from the sea, these dunes are planted with beach grass ( Ammophila arenaria ) to protect them from erosion by wind, water, and foot traffic. Storm surges threaten, in particular,
7776-510: 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
7884-420: 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
7992-531: The highest variability where there is fresh water inflow, such as at the Rhine and Elbe estuaries, the Baltic Sea exit and along the coast of Norway. The main pattern to the flow of water in the North Sea is an anti-clockwise rotation along the edges. The North Sea is an arm of the Atlantic Ocean receiving the majority of ocean current from the northwest opening, and a lesser portion of warm current from
8100-499: 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
8208-448: 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,
8316-418: The intended recipients". List of intelligence gathering disciplines This is a list of intelligence gathering disciplines . Human intelligence (HUMINT) are gathered from a person in the location in question. Sources can include the following: MI6 is often thought to use human intelligence to operate in different countries or Britain itself to protect the country from global affairs. However, this
8424-541: 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
8532-1045: The limits of the North Sea as follows: On the Southwest. A line joining the Phare de Walde (Walde Lighthouse, in France, 50°59'37"N, 1°54'53"E) and Leathercoat Point (England, 51°10'01.4"N 1°24'07.8"). northeast of Dover. On the Northwest. From Dunnet Head (58°40'20"N, 3°22'30"W) in Scotland to Tor Ness (58°47'N) in the Island of Hoy , thence through this island to the Kame of Hoy (58°55'N) on to Breck Ness on Mainland (58°58'N) through this island to Costa Head (3°14'W) and Inga Ness (59'17'N) in Westray through Westray, to Bow Head, across to Mull Head (North point of Papa Westray ) and on to Seal Skerry (North point of North Ronaldsay ) and thence to Horse Island (South point of
8640-489: The marine environment by preventing pollution from ships. Germany, Denmark, and the Netherlands also have a trilateral agreement for the protection of the Wadden Sea , or mudflats , which run along the coasts of the three countries on the southern edge of the North Sea. The North Sea has had various names throughout history. One of the earliest recorded names was Septentrionalis Oceanus , or "Northern Ocean", which
8748-562: 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
8856-410: 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
8964-639: 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
9072-631: 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
9180-615: The north it is bordered by the Shetland Islands , and connects with the Norwegian Sea , which is a marginal sea in the Arctic Ocean . The North Sea is more than 970 kilometres (600 mi) long and 580 kilometres (360 mi) wide, with an area of 750,000 square kilometres (290,000 sq mi) and a volume of 54,000 cubic kilometres (13,000 cu mi). Around the edges of the North Sea are sizeable islands and archipelagos , including Shetland , Orkney , and
9288-575: The north. It is more than 970 kilometres (600 mi) long and 580 kilometres (360 mi) wide, covering 570,000 square kilometres (220,000 sq mi). It hosts key north European shipping lanes and is a major fishery . The coast is a popular destination for recreation and tourism in bordering countries, and a rich source of energy resources, including wind and wave power . The North Sea has featured prominently in geopolitical and military affairs, particularly in Northern Europe , from
9396-425: The ocean, the North Sea was strategically important through both world wars. The coast has diverse geology and geography. In the north, deep fjords and sheer cliffs mark much of its Norwegian and Scottish coastlines respectively, whereas in the south, the coast consists mainly of sandy beaches, estuaries of long rivers and wide mudflats . Due to the dense population, heavy industrialisation , and intense use of
9504-461: 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
9612-500: The prevailing flood levels. It was only around the beginning of the High Middle Ages , in 1200 AD, that inhabitants began to connect single ring dikes into a dike line along the entire coast, thereby turning amphibious regions between the land and the sea into permanent solid ground. The modern form of the dikes supplemented by overflow and lateral diversion channels, began to appear in the 17th and 18th centuries, built in
9720-516: The sea and the area surrounding it, various environmental issues affect the sea's ecosystems. Adverse environmental issues – commonly including overfishing , industrial and agricultural runoff , dredging , and dumping, among others – have led to several efforts to prevent degradation and to safeguard long-term economic benefits. The North Sea is bounded by the Orkney Islands and east coast of Great Britain to
9828-469: The sea creating deep fjords and archipelagos . South of Stavanger, the coast softens, the islands become fewer. The eastern Scottish coast is similar, though less severe than Norway. From north east of England , the cliffs become lower and are composed of less resistant moraine , which erodes more easily, so that the coasts have more rounded contours. In the Netherlands, Belgium and in East Anglia
9936-417: 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
10044-413: The shores of the sea clogging harbours and inlets and has become a nuisance. Due to the heavy human populations and high level of industrialization along its shores, the wildlife of the North Sea has suffered from pollution, overhunting, and overfishing. Flamingos and pelicans were once found along the southern shores of the North Sea, but became extinct over the second millennium. Walruses frequented
10152-509: 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
10260-471: The smaller opening at the English Channel. These tidal currents leave along the Norwegian coast. Surface and deep water currents may move in different directions. Low salinity surface coastal waters move offshore, and deeper, denser high salinity waters move inshore. The North Sea located on the continental shelf has different waves from those in deep ocean water. The wave speeds are diminished and
10368-451: 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
10476-508: 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
10584-825: The uplands of the Fennoscandian Shield and the British Isles. This precursor of the current North Sea has grown and shrunk with the rise and fall of the eustatic sea level during geologic time. Sometimes it was connected with other shallow seas, such as the sea above the Paris Basin to the south-west, the Paratethys Sea to the south-east, or the Tethys Ocean to the south. During the Late Cretaceous, about 85 million years ago , all of modern mainland Europe except for Scandinavia
10692-504: The war on the side of Japan. During the First World War , Great Britain's Grand Fleet and Germany's Kaiserliche Marine faced each other in the North Sea, which became the main theatre of the war for surface action. Britain's larger fleet and North Sea Mine Barrage were able to establish an effective blockade for most of the war, which restricted the Central Powers ' access to many crucial resources. Major battles included
10800-406: The wave amplitudes are increased. In the North Sea there are two amphidromic systems and a third incomplete amphidromic system. In the North Sea the average tide difference in wave amplitude is between zero and eight metres (26 ft). The Kelvin tide of the Atlantic Ocean is a semidiurnal wave that travels northward. Some of the energy from this wave travels through the English Channel into
10908-513: The west and the northern and central European mainland to the east and south, including Norway , Denmark , Germany , the Netherlands , Belgium , and France . In the southwest, beyond the Straits of Dover , the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat , narrow straits that separate Denmark from Norway and Sweden respectively. In
11016-532: Was a scattering of islands. By the Early Oligocene , 34 to 28 million years ago , the emergence of Western and Central Europe had almost completely separated the North Sea from the Tethys Ocean, which gradually shrank to become the Mediterranean as Southern Europe and South West Asia became dry land. The North Sea was cut off from the English Channel by a narrow land bridge until that
11124-566: Was breached by at least two catastrophic floods between 450,000 and 180,000 years ago. Since the start of the Quaternary period about 2.6 million years ago , the eustatic sea level has fallen during each glacial period and then risen again. Every time the ice sheet reached its greatest extent, the North Sea became almost completely dry, the dry landmass being known as Doggerland , whose northern regions were themselves known to have been glaciated. The present-day coastline formed after
11232-632: Was cited by Pliny . He also noted that the Cimbri called it Morimarusa – "Dead Sea". The name "North Sea" probably came into English, however, via the Dutch Noordzee , who named it thus either in contrast with the Zuiderzee ("South Sea"), located south of Frisia , or because the sea is generally to the north of the Netherlands. Before the adoption of "North Sea", the names used in English were "German Sea" or "German Ocean", referred to as
11340-630: 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
11448-558: 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
11556-493: 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
11664-689: 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
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