Imagery intelligence (IMINT), pronounced as either as ''Im-Int'' or ''I-Mint'', is an intelligence gathering discipline wherein

image An image is a visual representation of something. It can be two-dimensional, three-dimensional, or somehow otherwise feed into the visual system to convey information. An image can be an artifact, such as a photograph or other two-dimensio ...

ry is analyzed (or "exploited") to identify information of intelligence value. Imagery used for defense intelligence purposes is generally collected via

satellite imagery Satellite images (also Earth observation imagery, spaceborne photography, or simply satellite photo) are images of Earth collected by imaging satellites operated by governments and businesses around the world. Satellite imaging companies sell ima ...

or aerial photography. As an intelligence gathering discipline, IMINT production depends heavily upon a robust intelligence collection management system. IMINT is complemented by non-imaging

MASINT Measurement and signature intelligence (MASINT) is a technical branch of intelligence gathering, which serves to detect, track, identify or describe the distinctive characteristics (signatures) of fixed or dynamic target sources. This often incl ...

electro-optical and radar sensors.

History

Origins

Although aerial photography was first used extensively in the

First World War World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was List of wars and anthropogenic disasters by death toll, one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, ...

, it was only in the

Second World War World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposi ...

that specialized imagery intelligence operations were initiated. High quality images were made possible with a series of innovations in the decade leading up to the war. In 1928, the RAF developed an electric heating system for the aerial camera. This allowed reconnaissance aircraft to take pictures from very high altitudes without the camera parts freezing. In 1939, Sidney Cotton and Flying Officer Maurice Longbottom of the RAF suggested that airborne reconnaissance may be a task better suited to fast, small aircraft which would use their speed and high service ceiling to avoid detection and interception. They proposed the use of

Spitfires The Supermarine Spitfire is a British single-seat fighter aircraft used by the Royal Air Force and other Allied countries before, during, and after World War II. Many variants of the Spitfire were built, from the Mk 1 to the Rolls-Royce Gri ...

with their armament and

radio Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 30 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a tr ...

s removed and replaced with extra fuel and cameras. This led to the development of the Spitfire PR variants. These planes had a maximum speed of 396 mph at 30,000 feet with their armaments removed, and were used for photo-reconnaissance missions. The aircraft were fitted with five cameras which were heated to ensure good results. The systematic collection and interpretation of the huge amounts of aerial reconnaissance intelligence data soon became imperative. Beginning in 1941, RAF Medmenham was the main interpretation centre for photographic reconnaissance operations in the European and

Mediterranean The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on ...

theatres.Unlocking Buckinghamshire's Past
/ref> The ''

Central Interpretation Unit MI4 was a department of the British Directorate of Military Intelligence, Section 4, part of the War Office. It was responsible for aerial reconnaissance and interpretation. It developed into the JARIC intelligence agency. The present day su ...

'' (CIU) was later amalgamated with the Bomber Command Damage Assessment Section and the Night Photographic Interpretation Section of No 3 Photographic Reconnaissance Unit, RAF Oakington, in 1942.Allied Central Interpretation Unit (ACIU)
During 1942 and 1943, the CIU gradually expanded and was involved in the planning stages of practically every operation of the war, and in every aspect of intelligence. In 1945, daily intake of material averaged 25,000 negatives and 60,000 prints. Thirty-six million prints were made during the war. By VE-day, the print library, which documented and stored worldwide cover, held 5,000,000 prints from which 40,000 reports had been produced. American personnel had for some time formed an increasing part of the CIU and on 1 May 1944 this was finally recognized by changing the title of the unit to the ''Allied Central Interpretation Unit'' (ACIU). There were then over 1,700 personnel on the unit's strength. A large number of photographic interpreters were recruited from the Hollywood Film Studios including

Xavier Atencio Francis Xavier Atencio, also known as X Atencio (September 4, 1919 – September 10, 2017) was an animator and Imagineer for The Walt Disney Company. He is perhaps best known for writing the scripts and song lyrics of the Disney theme park attra ...

. Two renowned archaeologists also worked there as interpreters: Dorothy Garrod, the first woman to hold an Oxbridge Chair, and Glyn Daniel, who went on to gain popular acclaim as the host of the television game show ''

Animal, Vegetable or Mineral? ''Animal, Vegetable, Mineral?'' was a popular television game show which ran from 1952 to 1959. In the show, a panel of archeologists, art historians, and natural history experts were asked to identify interesting objects or artifacts from muse ...

''.

Sidney Cotton's aerial photographs were far ahead of their time. Together with other members of his reconnaissance squadron, he pioneered the technique of high-altitude, high-speed photography that was instrumental in revealing the locations of many crucial military and intelligence targets. Cotton also worked on ideas such as a prototype specialist reconnaissance aircraft and further refinements of photographic equipment. At its peak, British reconnaissance flights yielded 50,000 images per day to interpret. Of particular significance in the success of the work of Medmenham was the use of

stereoscopic Stereoscopy (also called stereoscopics, or stereo imaging) is a technique for creating or enhancing the illusion of depth in an image by means of stereopsis for binocular vision. The word ''stereoscopy'' derives . Any stereoscopic image is ...

images, using a between plate overlap of exactly 60%. Despite initial scepticism about the possibility of the German rocket technology, major operations, including the 1943 offensives against the

V-2 The V-2 (german: Vergeltungswaffe 2, lit=Retaliation Weapon 2), with the technical name ''Aggregat 4'' (A-4), was the world’s first long-range guided ballistic missile. The missile, powered by a liquid-propellant rocket engine, was develope ...

rocket development plant at Peenemünde, were made possible by painstaking work carried out at Medmenham. Later offensives were also made against potential launch sites at

Wizernes Wizernes (; vls, Wezerne) is a commune in the Pas-de-Calais department, northern France. It lies southwest of Saint-Omer on the banks of the river Aa at the D928 and D211 road junction. The commune is twinned with Ensdorf, Germany. Populat ...

and 96 other launch sites in northern France. It is claimed that Medmanham's greatest operational success was " Operation Crossbow" which, from 23 December 1943, destroyed the V-1 infrastructure in northern France."Operation Crossbow", BBC2, broadcast 15 May 2011
/ref> According to R.V. Jones, photographs were used to establish the size and the characteristic launching mechanisms for both the

V-1 flying bomb The V-1 flying bomb (german: Vergeltungswaffe 1 "Vengeance Weapon 1") was an early cruise missile. Its official Reich Aviation Ministry () designation was Fi 103. It was also known to the Allies as the buzz bomb or doodlebug and in Germany ...

and the

V-2 rocket The V-2 (german: Vergeltungswaffe 2, lit=Retaliation Weapon 2), with the technical name ''Aggregat 4'' (A-4), was the world’s first long-range guided ballistic missile. The missile, powered by a liquid-propellant rocket engine, was develop ...

Post war spyplanes

Immediately after World War II, long range aerial reconnaissance was taken up by adapted jet bombers – such as the

English Electric Canberra The English Electric Canberra is a British first-generation, jet-powered medium bomber. It was developed by English Electric during the mid- to late 1940s in response to a 1944 Air Ministry requirement for a successor to the wartime de Havil ...

, and its American development, the Martin B-57 – capable of flying higher or faster than the enemy. Highly specialized and secretive strategic reconnaissance aircraft, or spy planes, such as the

Lockheed U-2 The Lockheed U-2, nicknamed "''Dragon Lady''", is an American single- jet engine, high altitude reconnaissance aircraft operated by the United States Air Force (USAF) and previously flown by the Central Intelligence Agency (CIA). It provides d ...

and its successor, the SR-71 Blackbird were developed by the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

. Flying these aircraft became an exceptionally demanding task, as much because of the aircraft's extreme speed and altitude as the risk of being captured as spies. As a result, the crews of these aircraft were invariably specially selected and trained. There are claims that the US constructed a

hypersonic In aerodynamics, a hypersonic speed is one that exceeds 5 times the speed of sound, often stated as starting at speeds of Mach 5 and above. The precise Mach number at which a craft can be said to be flying at hypersonic speed varies, since ind ...

reconnaissance aircraft, dubbed the Aurora, in the late 1980s to replace the Blackbird. Since the early 1960s, in the United States aerial and satellite reconnaissance has been coordinated by the National Reconnaissance Office.

Early use of satellites

Early photographic reconnaissance satellites used photographic film, which was exposed on-orbit and returned to earth for developing. These satellites remained in orbit for days, weeks, or months before ejecting their film-return vehicles, called "buckets." Between 1959 and 1984 the U.S. launched around 200 such satellites under the codenames CORONA and GAMBIT, with ultimate photographic resolution (ground-resolution distance) better than . The first successful mission concluded on 1960-08-19 with the mid-air recovery by a C-119 of film from the Corona mission code-named Discoverer 14. This was the first successful recovery of film from an orbiting satellite and the first aerial recovery of an object returning from Earth orbit. Because of a tradeoff between area covered and ground resolution, not all reconnaissance satellites have been designed for high resolution; the

KH-5 KH-5 ARGON was a series of reconnaissance satellites produced by the United States from February 1961 to August 1964. The KH-5 operated similarly to the CORONA series of satellites, as it ejected a canister of photographic film. At least ...

-ARGON program had a ground resolution of 140 meters and was intended for mapmaking. Between 1961 and 1994 the USSR launched perhaps 500 Zenit film-return satellites, which returned both the film and the camera to earth in a pressurized capsule. The U.S. KH-11 series of satellites, first launched in 1976, was made by Lockheed, the same contractor who built the

Hubble Space Telescope The Hubble Space Telescope (often referred to as HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most vers ...

. HST has a 2.4 metre telescope mirror and is believed to have had a similar appearance to the KH-11 satellites. These satellites used charge-coupled devices, predecessors to modern digital cameras, rather than film. Russian reconnaissance satellites with comparable capabilities are named Resurs DK and Persona.

Aircraft

Low- and high-flying planes have been used all through the last century to gather intelligence about the enemy. U.S. high-flying reconnaissance planes include the

, and the much faster SR-71 Blackbird, (retired in 1998). One advantage planes have over satellites is that planes can usually produce more detailed photographs and can be placed over the target more quickly, more often, and more cheaply, but planes also have the disadvantage of possibly being intercepted by aircraft or missiles such as in the 1960 U-2 incident.

Unmanned aerial vehicle An unmanned aerial vehicle (UAV), commonly known as a drone, is an aircraft without any human pilot, crew, or passengers on board. UAVs are a component of an unmanned aircraft system (UAS), which includes adding a ground-based controll ...

s have been developed for imagery and signals intelligence. These drones are a force multiplier by giving the battlefield commander an "eye in the sky" without risking a pilot.

Satellite

Though the resolution of satellite photographs, which must be taken from distances of hundreds of kilometers, is usually poorer than photographs taken by air, satellites offer the possibility of coverage for much of the earth, including hostile territory, without exposing human pilots to the risk of being shot down. TheGambitStoryPage154

There have been hundreds of reconnaissance satellites launched by dozens of nations since the first years of space exploration. Satellites for imaging intelligence were usually placed in high-inclination

low Earth orbit A low Earth orbit (LEO) is an orbit around Earth with a period of 128 minutes or less (making at least 11.25 orbits per day) and an eccentricity less than 0.25. Most of the artificial objects in outer space are in LEO, with an altitude never m ...

s, sometimes in

Sun-synchronous orbit A Sun-synchronous orbit (SSO), also called a heliosynchronous orbit, is a nearly polar orbit around a planet, in which the satellite passes over any given point of the planet's surface at the same local mean solar time. More technically, it is ...

s. Since the film-return missions were usually short, they could indulge in orbits with low

perigee An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any el ...

s, in the range of 100–200 km, but the more recent CCD-based satellites have been launched into higher orbits, 250–300 km perigee, allowing each to remain in orbit for several years. While the exact resolution and other details of modern spy satellites are classified, some idea of the trade-offs available can be made using simple physics. The formula for the highest possible resolution of an optical system with a circular aperture is given by the Rayleigh criterion: :

\sin \theta = 1.22 \frac.

Using :

\sin \theta =  \frac,

we can get :

\text =  1.22\frac \text,

where ''θ'' is the angular resolution, ''λ'' is the

wavelength In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats. It is the distance between consecutive corresponding points of the same phase on the wave, such as two adjacent crests, tr ...

of light, and ''D'' is the diameter of the lens or mirror. Were the

, with a 2.4 m telescope, designed for photographing Earth, it would be diffraction-limited to resolutions greater than 16 cm (6 inches) for green light (

\lambda \approx  550

nm) at its orbital altitude of 590 km. This means that it would be impossible to take photographs showing objects smaller than 16 cm with such a telescope at such an altitude. Modern U.S. IMINT satellites are believed to have around 10 cm resolution; contrary to references in popular culture, this is sufficient to detect any type of vehicle, but not to read the headlines of a newspaper. The primary purpose of most spy satellites is to monitor visible ground activity. While resolution and clarity of images has improved greatly over the years, this role has remained essentially the same. Some other uses of satellite imaging have been to produce detailed 3D maps for use in operations and missile guidance systems, and to monitor normally invisible information such as the growth levels of a country's crops or the heat given off by certain facilities. Some of the multi-spectral sensors, such as thermal measurement, are more

electro-optical MASINT Electro-optical MASINT is a subdiscipline of Measurement and Signature Intelligence, (MASINT) and refers to intelligence gathering activities which bring together disparate elements that do not fit within the definitions of Signals Intelligence ( ...

than true IMINT platforms. To counter the threat posed by these "eyes in the sky," the

USSR The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen nati ...

Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-ei ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's List of countries and dependencies by population, most populous country, with a Population of China, population exceeding 1.4 billion, slig ...

and

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area, the List of countries and dependencies by population, second-most populous ...

have developed systems for destroying enemy spy satellites (either with the use of another 'killer satellite', or with some sort of Earth- or air-launched missile). Since 1985, commercial vendors of

have entered the market, beginning with the French

SPOT Spot or SPOT may refer to: Places * Spot, North Carolina, a community in the United States * The Spot, New South Wales, a locality in Sydney, Australia * South Pole Traverse, sometimes called the South Pole Overland Traverse People * Spot (produ ...

satellites, which had resolutions between 5 and 20 metres. Recent high-resolution (4–0.5 metre) private imaging satellites include TerraSAR-X, IKONOS, Orbview, QuickBird and Worldview-1, allowing any country (or any business for that matter) to buy access to satellite images.

Analytical Methodology

The value of IMINT reports are determined on a balance between the timeliness and robustness of the intelligence product. As such, the fidelity of intelligence that may be gleaned from imagery analysis is a traditionally perceived by intelligence professionals as a function of the amount of time an imagery analyst (IA) has to exploit a given image or set of imagery. As such, the

United States Army The United States Army (USA) is the land service branch of the United States Armed Forces. It is one of the eight U.S. uniformed services, and is designated as the Army of the United States in the U.S. Constitution.Article II, section 2, ...

field manual breaks IMINT analysis into three distinct phases, based upon the amount of time expended in exploiting any given image.https://fas.org/irp/doddir/army/fm2-0.pdf

First Phase

First phase imagery analysis is deemed "time-dominant." This means that given imagery must be rapidly exploited in order to satisfy an immediate requirement for imagery-sourced intelligence from which a leader may make an educated political and/or military decision. Due to the need to produce near-real time intelligence assessments based upon collected imagery, first phase imagery analysis is rarely compared to collateral intelligence.

Second Phase

Second phase imagery analysis is centered on the further exploitation of recently collected imagery to support short- to mid-term decision-making. Like first phase imagery analysis, second phase imagery analysis is generally catalyzed by a local commander's Priority Intelligence Requirements, at least in the context of a military operational setting. Whereas first phase imagery analysis may depend on the exploitation of a relatively small repository of imagery, or even a single image, second phase imagery analysis generally mandates a review of a chronological set of imagery over time, so as to establish a temporal understanding of objects and/or activities of interest.

Third Phase

Third phase imagery analysis is generally conducted in order to satisfy strategic intelligence questions or to otherwise explore existing data in the search of "discovery intelligence." Third phase imagery analysis hinges on the use of a large repository of historical imagery as well as access to a variety of sources of information. Third phase imagery analysis incorporates supporting information and intelligence from other intelligence gathering disciplines and is, therefore, generally conducted in support of a multi-source intelligence team. The exploitation of imagery at this level of analysis is typically conducted with the intention of producing

Geospatial Intelligence In the United States, geospatial intelligence (GEOINT) is intelligence about the human activity on earth derived from the exploitation and analysis of imagery, signals, or signatures with geospatial information. GEOINT describes, assesses, and v ...

(GEOINT).

Notes

External links

Australian Defence Satellite Communications Station, GeraldtonJoint Australian-US intelligence facility - Pine Gap
{{Intelligence cycle management Intelligence gathering disciplines Photography by genre Aerial reconnaissance Photography and videography of Earth