|
During 1914-18, driven primarily by the introduction of heavier-than-air aircraft, aerial reconnaissance developed from an almost zero baseline to a vast, complex science. Equipment, tactics, procedures and terminology that would survive with modifications to this day had their origins in this period. ==Beginnings== The first use of an airplane war was a reconnaissance flight performed on 23 October 1911 by Captain Carlo Maria Piazza in a Blériot XI during the Italo-Turkish War in Tripolitania. Military aerial photography began that December. The experience in World War I would begin on very similar terms, with French Bleriot and German Taube monoplanes. Reconnaissance was widely perceived as the only practical use of airplanes. While most of the combatant countries possessed a few military aircraft in August 1914, these were almost exclusively devoted to reconnaissance and artillery spotting), supplementing well-tried and familiar platforms like balloons and kites. Tethered balloons could ascend to as high as a mile, but were easy to shoot down. Furthermore, they were unstable observation platforms in any wind, leading to attempts to stabilize them with kite-tails or drogues attached to the basket. Dirigibles like the huge new German Zeppelins were considered the best reconnaissance platforms and they served effectively for maritime patrols. Vertical camera installations were used from the beginning of the war, but they were too heavy and bulky for light airplanes, and most early reconnaissance from airplanes consisted of visual observation and written reports. Handheld cameras were widely used but with disappointing results. Good photographs required both skilled flying and an operator who could devote time to handle the camera and the unwieldy and heavy glass plates it required. In time, longer focal length lenses were used, cameras and gear grew lighter and bigger, and for survival, operating altitudes increased up to the 12-18,000 foot level. Driven high, aircrews began to use oxygen and heated clothing items. The critical discipline of communicating results led to rampant improvisation. At first it was not uncommon for aircraft to land next to command posts so the pilot could personally pass on urgent information. For artillery spotting, time was of the essence, and the French tried air-dropped messaging, colored flares, and pre-arranged aircraft maneuvers to convey information. France was reportedly the first to try airborne radios, often transmitters alone due to the weight penalty; others maintain that Britain preceded with the light-weight Sterling radio set in aircraft by 1915. Germany had a scientific lead and adopted the first aerial camera, a Görz, in 1913. Austria-Hungary followed their lead. Just two weeks into the war, reporters noted of airplanes: “They have ranged constantly over the enemy’s positions, so that the French have always known what the Germans have been doing. This has so disconcerted the latter that they are now making efforts to frighten the French air scouts away.” By 17 August 1914 and repeatedly thereafter, Belgian “air scouts” reported on German troop movements.〔New York Times, 15 August, 17 August, 22 August, 4 November 1914.〕 France was by far the aeronautical leader at the time, and the French Army had incorporated cameras in airplanes from the beginning. France began the war with several squadrons of Blériot observation planes. The French Army developed procedures for getting prints into the hands of field commanders quickly. In Britain, then lagging far behind in aviation, the reconnaissance pioneer F.C.V. Laws established the first heavier-than-air photography unit at Farnborough in 1913, using a Farman fitted with a Watson camera. In stark contrast with the French, early British reconnaissance was essentially conducted on an amateur basis, lacking in official backing. The United States played an important role in the last months of the war, using French aircraft and modified cameras. Some techniques and equipment used in civilian surveying and mapping were developed by the US Army Corps of Engineers when the topographic engineer, James W. Bagley, transferred from the US Geological Survey to the army.〔Bagley, James Warren. 1917. (''The use of the panoramic camera in topographic surveying: with notes on the application of photogrammetry to aerial surveys'' ). US Geological Survey Bulletin #657. Washington: Government Printing Office.〕 Major Bagley brought his recently invented tri-lens camera to France, where it was used to make one vertical and two oblique images from airplanes. These images were used to overprint enemy trenches and gun emplacements over existing maps for precision targeting. An example of this camera is held at the Smithsonian Institution: "This object is on display in the Boeing Aviation Hangar at the Steven F. Udvar-Hazy Center in Chantilly, VA. Fairchild Aerial Camera Corporation built the production model of the T-2 and T-2A four-lens camera, which improved upon the T-1 tri-lens mapping camera developed by Maj. James Bagley of the U.S. Army Signal Corps. The T-2A had one vertical lens and three oblique lenses set at 35 degrees, which provided a 120-degree field of view at right angles to the direction of flight. Four lens caps are also displayed."〔(Camera, Aerial, Mapping, Fairchild T-2A ). National Air and Space Museum.〕 Italy and Russia had prominent roles as well, with Italy deploying some of the best performing aircraft. The small Ottoman air forces were mostly an extension of German air power. The failure of the Schlieffen Plan offensive in 1914 is attributed in part to French air superiority blinding German reconnaissance, but the German victory at Tannenberg is thought to have been helped by prompt response to air intelligence about Russian movements. Despite the improvised start, all sides quickly learned the importance of aerial photography, and by 1916 heavier-than-air reconnaissance was a regular practice along the front. This in turn necessitated fighter escorts, and thus drove much of the rapid aeronautical progress of the four years of war. Support of ground forces was almost the sole role of reconnaissance; strategic air war concepts were as yet embryonic. At sea, lighter-than-air photography still dominated; but Zeppelins turned out to be very vulnerable over settled areas. Flying boats and seaplanes ("Hydro-aeroplanes")came into their own for coastal patrol duties. By the end of the war both sides maintained detailed maps of the front derived from mosaics of aerial photograps. Germany alone reportedly generated 4,000 images a day in 1918. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Aerial reconnaissance in World War I」の詳細全文を読む スポンサード リンク
|