Introduction to UAV Systems. Mohammad H. Sadraey

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СКАЧАТЬ Bug could fly nearly 40 mi at 55 mi/h and carry 180 lb of high explosives. The air vehicle was guided to the target by pre‐set controls and had detachable wings that were released when over the target, allowing the fuselage to plunge to the ground as a bomb. Also, in 1917, Lawrence Sperry developed a UAV, similar to Kettering’s, for the Navy, called the Sperry‐Curtis Aerial Torpedo. It made several successful flights out of Sperry’s Long Island airfield, but was not used in the war.

      We often hear of the UAV pioneers who developed the early aircraft, but other pioneers were instrumental in inventing or developing important parts of the system. One was Archibald Montgomery Low, who developed data links. Professor Low, born in England in 1888, was known as the “Father of Radio Guidance Systems.” He developed the first data link and solved interference problems caused by the UAV engine. His first UAVs crashed, but on September 3, 1924, he made the world’s first successful radio‐controlled flight. He was a prolific writer and inventor and died in 1956.

      In 1933, the British flew three refurbished Fairey Queen biplanes by remote control from a ship. Two crashed, but the third flew successfully, making Great Britain the first country to fully appreciate the value of UAVs, especially after they decided to use one as a target and couldn’t shoot it down.

      In 1937 another Englishman, Reginald Leigh Denny, and two Americans, Walter Righter and Kenneth Case, developed a series of UAVs called RP‐1, RP‐2, RP‐3, and RP‐4. They formed a company in 1939 called the Radioplane Company, which later became part of the Northrop‐Ventura Division. Radioplane built thousands of target drones during World War II. (One of their early assemblers was Norma Jean Daugherty, later known as Marilyn Monroe.) Of course, the Germans used lethal UAVs (V‐1’s and V‐2’s) during the later years of the war, but it was not until the Vietnam War era that UAVs were successfully used for reconnaissance.

      1.2.2 The Vietnam War

      The first real use of UAVs by the United States in a combat reconnaissance role began during the Vietnam War. UAVs, such as the AQM‐34 Firebee developed by Teledyne Ryan, were used for a wide range of missions, such as intelligence gathering, decoys, and leaflet dropping.

During the Vietnam War era, UAVs were used extensively in combat, but for reconnaissance missions only. The air vehicles were usually air launched from C‐130’s and recovered by parachute. The air vehicles were what might be called deep penetrators and were developed from existing target drones.

      The impetus to operations in Southeast Asia came from activities during the Cuban Missile Crisis when UAVs were developed for reconnaissance but not used because the crisis ended before they became available. One of the first contracts was between Ryan and the Air Force, known as 147A, for vehicles based on the Ryan Firebee target drone (stretched versions). This was in 1962 and they were called Fireflys. Although the Fireflys were not operational during the Cuban crisis, they set the stage for Vietnam. Northrop also improved their early designs, which were essentially model airplanes, to jet‐propelled deep penetrators, but stuck mostly to target drones. The Ryan Firefly was the primary air vehicle used in Southeast Asia.

      A total of 3,435 sorties were flown, and most of these (2,873, or nearly 84%) were recovered. One air vehicle, the TOMCAT, successfully completed 68 missions before it was lost. Another vehicle completed 97.3% of its missions of low‐altitude, real‐time photography. By the end of the Vietnam War in 1972, air vehicles were experiencing 90% success rates [1].

      1.2.3 Resurgence

      At the end of the Vietnam War, general interest in UAVs dwindled until the Israelis neutralized the Syrian air defense system in the Bekaa Valley in 1982 using UAVs for reconnaissance, jamming, and decoys. The Israeli Air Force pioneered several UAVs in the early 1980s. In 1982, United States observers noted Israel’s use of UAVs in Lebanon and persuaded the Navy to acquire a UAV capability. One of the early UAVs acquired by the Navy was the RQ‐2 Pioneer. It was developed jointly by AAI Corporation and Israeli Aircraft Industries and became a very useful air vehicle during Desert Storm for collecting tactical intelligence.

      Actually, the Israeli UAVs were not as technically successful as many people believe, with much of their operational success being achieved through the element of surprise rather than technical sophistication. The air vehicle was basically unreliable and couldn’t fly at night, and the data‐link transmissions interfered with the manned fighter communications. However, they proved that UAVs could perform valuable, real‐time combat service in an operational environment.

      The United States began to work again on UAVs in August 1971 when the Defense Science Board recommended mini‐RPVs for artillery target spotting and laser designation. In February 1974, the Army’s Material Command established an RPV weapons system management office and by the end of that year (December) a “Systems Technology Demonstration” contract was awarded to Lockheed Aircraft Company, with the air vehicle subcontracted to Developmental Sciences Incorporated (later DSC, Lear Astronics, Ontario, CA). The launcher was manufactured by All American Engineering (later ESCO‐Datron), and the recovery net system by Dornier of the then still‐partitioned West Germany. Ten bidders competed for the program. The demonstration was highly successful, proving the concept to be feasible. The system was flown by Army personnel and accumulated more than 300 flight hours.

In September 1978, the so‐called Target Acquisition/Designation and Aerial Reconnaissance System (TADARS) required operational capability (ROC) was approved, and approximately 1 year later, in August 1979, a 43‐month Full Scale Engineering Development (FSED) contract was awarded to Lockheed as the sole source. The system was given the name “Aquila” and is discussed in more detail at the end of this chapter. For a number of reasons that provide important lessons to UAV system developers, Aquila development stretched out for many years and the system was never fielded.

      In 1984, partly as a result of an urgent need and partly because the Army desired some competition for Aquila, the Army started a program called Gray Wolf, which demonstrated, for the first time for a UAV, hundreds of hours of night operations in what could be called “combat conditions.” This program, still partly classified, was discontinued because of inadequate funding.

      1.2.4 Joint Operations

      The US Navy and Marine Corps entered the UAV arena in 1985 by purchasing the Mazlat/Israeli Aircraft Industries (IAI) and AAI Pioneer system, which suffered considerable growing pains but still remains in service. However, Congress by this time became restless and demanded that a joint project office (JPO) be formed so that commonality and interoperability among the services would be maximized. The JPO was put under the administrative control of the Department of the Navy. This office has developed a master plan that not only defines the missions but also describes the desirable features for each kind of system needed by the services. Some elements of this plan will be discussed in Chapter 2 in the section called “Classes of UAV Systems.”

      The US Air Force was initially reluctant to embrace UAVs, notwithstanding their wealth of experience with target‐drone unmanned aircraft. However, this attitude changed significantly during the 1990s and the Air Force not only has been very active in developing and using UAVs for a variety of purposes but also has been the most active of the four US services in attempting to take control of all UAV programs and assets within the US military.

      1.2.5 Desert Storm

      The invasion of Iraq to Kuwait in 1990–1991 allowed military planners an opportunity to use UAVs in combat conditions. They found them to be a highly desirable asset even though the performance of the systems then available was less than satisfactory in many ways. Five UAV systems were used in the operation: (1) the СКАЧАТЬ