Aerial reconnaissance is reconnaissance for a military or strategic purpose that is conducted using reconnaissance aircraft. The role of reconnaissance can fulfil a variety of requirements including artillery spotting, the collection of imagery intelligence, and the observation of enemy maneuvers.
History
Early developments
After the French Revolution, the new rulers became interested in using the balloon to observe enemy manoeuvres and appointed scientist Charles Coutelle to conduct studies using the balloon L'Entreprenant, the first military reconnaissance aircraft. The balloon found its first use in the 1794 conflict with Austria, where in the Battle of Fleurus they gathered information. Moreover, the presence of the balloon had a demoralizing effect on the Austrian troops, which improved the likelihood of victory for the French troops. To operate such balloons, a new unit of the French military, the French Aerostatic Corps, was established; this organisation has been recognised as being the world's first air force.
After the invention of photography, primitive aerial photographs were made of the ground from manned and unmanned balloons, starting in the 1860s, and from tethered kites from the 1880s onwards. An example was Arthur Batut's kite-borne camera photographs of Labruguière starting from 1889.
In the early 20th century, Julius Neubronner experimented with pigeon photography. These pigeons carried small cameras that incorporated timers. (photographs by Alfred Nobel's rocket and the Bavarian pigeon fleet)
Ludwig Rahrmann in 1891 patented a means of attaching a camera to a large calibre artillery projectile or rocket, and this inspired Alfred Maul to develop his Maul Camera Rockets starting in 1903. Alfred Nobel in 1896 had already built the first rocket carrying a camera, which took photographs of the Swedish landscape during its flights. Maul improved his camera rockets and the Austrian Army even tested them in the Turkish-Bulgarian War in 1912 and 1913, but by then and from that time on camera-carrying aircraft were found to be superior. (summary and photo)
The first use of airplanes in combat missions was by the Italian Air Force during the Italo-Turkish War of 1911–1912. On 23 October 1911, an Italian pilot, Capt. Carlo Piazza, flew over the Turkish lines in Libya to conduct an aerial reconnaissance mission; Another aviation first occurred on November 1 with the first ever dropping of an aerial bomb, performed by Sottotenente Giulio Gavotti, on Turkish troops from an early model of Etrich Taube aircraft.U.S. Centennial of Flight Commission: Aviation at the Start of the First World War
The first reconnaissance flight in Europe took place in Greece, over Thessaly, on 18 October 1912 (5 October by the Julian calendar) over the Ottoman army.Walter J. Boyne (ed.) Air Warfare: an International Encyclopedia: A-L, p. 66 Note: The correct date in the Gregorian calendar is 18 October, not 21 as the source claims. The pilot also dropped some hand-grenades over the Turkish Army barracks, although without success. This was the first day of the Balkan wars, and during the same day a similar mission was flown by German mercenaries in Ottoman service in the Thrace front against the Bulgarians. The Greek and the Ottoman mission flown during the same day are the first military aviation combat missions in a conventional war. A few days later, on 16 October 1912, a Bulgarian Albatros aircraft performed one of Europe's first reconnaissance flight in combat conditions, against the Turkish lines on the Balkan Peninsula, during the Balkan Wars of 1912–1913.
Maturation during the First World War
The use of aerial photography rapidly matured during the First World War, as aircraft used for reconnaissance purposes were outfitted with cameras to record enemy movements and defences. At the start of the conflict, the usefulness of aerial photography was not fully appreciated, with reconnaissance being accomplished with map sketching from the air.
Frederick Charles Victor Laws started experiments in aerial photography in 1912 with No. 1 Squadron RAF using the British dirigible Beta. He discovered that vertical photos taken with 60% overlap could be used to create a stereoscopic effect when viewed in a stereoscope, thus creating a perception of depth that could aid in cartography and in intelligence derived from aerial images. The dirigibles were eventually allocated to the Royal Navy, so Laws formed the first aerial reconnaissance unit of fixed-wing aircraft; this became No. 3 Squadron RAF.
Germany was one of the first countries to adopt the use of a camera for aerial reconnaissance, opting for a Görz, in 1913. French Military Aviation began the war with several squadrons of Bleriot observation planes, equipped with cameras for reconnaissance. The French Army developed procedures for getting prints into the hands of field commanders in record time.
The Royal Flying Corps recon pilots began to use cameras for recording their observations in 1914 and by the Battle of Neuve Chapelle in 1915 the entire system of German trenches was being photographed. The first purpose-built and practical aerial camera was invented by Captain John Moore-Brabazon in 1915 with the help of the Thornton-Pickard company, greatly enhancing the efficiency of aerial photography. The camera was inserted into the floor of the aircraft and could be triggered by the pilot at intervals.
Moore-Brabazon also pioneered the incorporation of stereoscopic techniques into aerial photography, allowing the height of objects on the landscape to be discerned by comparing photographs taken at different angles. In 1916, the Austro-Hungarian Empire made vertical camera axis aerial photos above Italy for map-making.
By the end of the war, aerial cameras had dramatically increased in size and focal power and were used increasingly frequently as they proved their pivotal military worth; by 1918 both sides were photographing the entire front twice a day and had taken over half a million photos since the beginning of the conflict.
In January 1918, General Allenby used five Australian pilots from No. 1 Squadron AFC to photograph a area in Palestine as an aid to correcting and improving maps of the Turkish front. This was a pioneering use of aerial photography as an aid for cartography. Lieutenants Leonard Taplin, Allan Runciman Brown, H. L. Fraser, Edward Patrick Kenny, and L. W. Rogers photographed a block of land stretching from the Turkish front lines deep into their rear areas. Beginning 5 January, they flew with a fighter escort to ward off enemy fighters. Using Royal Aircraft Factory BE.12 and Martinsyde airplanes, they not only overcame enemy air attacks, but also bucked 65 mile-per-hour winds, anti-aircraft fire, and malfunctioning equipment to complete their task circa 19 January 1918.
Second World War
High-speed reconnaissance aircraft
During 1928, the Royal Air Force (RAF) developed an electric heating system for the aerial camera; this innovation 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. Although this may perhaps seem obvious today with modern reconnaissance tasks performed by fast, high flying aircraft, at the time it was radical thinking.
Cotton and Longbottom proposed the use of Spitfires with their armament and radios removed and replaced with extra fuel and cameras. This concept led to the development of the Spitfire PR variants. With their armaments removed, these planes could attain a maximum speed of 396 mph while flying at an altitude of 30,000 feet, and were used for photo-reconnaissance missions. The Spitfire PR was fitted with five cameras, which were heated to ensure good results (while the cockpit was not). In the reconnaissance role, the Spitfire proved to be extremely successful, resulting in numerous Spitfire variants being built specifically for that purpose. These served initially with what later became No. 1 Photographic Reconnaissance Unit (PRU).
Other fighters were also adapted for photo-reconnaissance, including the British Mosquito and the American P-38 Lightning and P-51 Mustang. Such aircraft were painted in PRU Blue or Pink camouflage colours to make them difficult to spot in the air, and often were stripped of weapons or had engines modified for better performance at high altitudes (over ).
The American F-4, a factory modification of the Lockheed P-38 Lightning, replaced the nose-mounted four machine guns and cannon with four high-quality K-17 cameras. Approximately 120 F-4 and F-4As were hurriedly made available by March 1942, reaching the 8th Photographic Squadron in Australia by April (the first P-38s to see action). The F-4 had an early advantage of long range and high speed combined with ability to fly at high altitude; a potent combination for reconnaissance. In the last half of 1942 Lockheed would produce 96 F-5As, based on the P-38G with all later P-38 photo-reconnaissance variants designated F-5. In its reconnaissance role, the Lightning was so effective that over 1,200 F-4 and F-5 variants were delivered by Lockheed, and it was the United States Army Air Forces's (USAAF) primary photo-reconnaissance type used throughout the war in all combat theatres. The Mustang F-6 arrived later in the conflict and, by spring 1945, became the dominant reconnaissance type flown by the USAAF in the European theatre. American photo-reconnaissance operations in Europe were centred at RAF Mount Farm, with the resulting photographs transferred to Medmenham for interpretation. Approximately 15,000 Fairchild K-20 aerial cameras were manufactured for use in Allied reconnaissance aircraft between 1941 and 1945.
The British de Havilland Mosquito excelled in the photo-reconnaissance role; the converted bomber was fitted with three cameras installed in what had been the bomb bay. It had a cruising speed of 255 mph, maximum speed of 362 mph and a maximum altitude of 35,000 feet. The first converted PRU (Photo-Reconnaissance Unit) Mosquito was delivered to RAF Benson in July 1941 by Geoffrey de Havilland himself. The PR Mk XVI and later variants had pressurized cockpits and also pressurized central and inner wing tanks to reduce fuel vaporization at high altitude. The Mosquito was faster than most enemy fighters at 35,000 ft,Bowman 2005, p. 21. and could roam almost anywhere. Colonel Roy M. Stanley II of United States Air Force (USAF) stated of the aircraft: "I consider the Mosquito the best photo-reconnaissance aircraft of the war".Stanley 2010, p. 35. The United States Army Air Forces (USAAF) designation for the photo-reconnaissance Mosquito was F-8.