Radar Approach Control (RAPCON)

Introduction

In the late 19th century, Heinrich Hertz conducted experiments to show how radio waves could be reflected using metallic objects. The idea was made possible at James Clerk Maxwell’s seminar where projects related to electromagnetism were being conducted. In the early 20th century, systems were developed that used the principles of radio waves suggested by Heinrich Hertz and these systems became available for operations in the 20th century. The first inventor to use such systems was a German called Christian Hulsmeyer who built a device for ship detection using the principles. The ship detection device was used to help the ship avoid collisions in fog. Eventually, similar systems were produced to provide information about direction to objects over short distances. The emergence of systems that could produce short pulses of radio waves was the advancement that led to development of modern Radar Approach Control Systems (RAPCON). The pulses were timed on an oscilloscope to determine the range, the antenna showed the direction of the targeted location (Harris 23). When the two were combined, they produced a ‘fix’ which was easily used to locate the direction of the targets. During the period between 1934 and 1939, eight nations found RAPCON systems to be effective and efficient, therefore, they decided to use such types of systems in secrecy and independently. Amongst the nations were Japan, Netherlands, United States, United Kingdom, Germany and France.

Additionally, Britain decided to share information with New Zealand, South Africa, Canada, and the United States. These countries used the information received from Britain to develop their own Radar Approach Systems. The term RADAR was introduced in 1939 by the Signal Corps of the United States as they operated on the Navy systems. During World War II, there was rapid and significance progress which led to the development of magnetron in the UK. The magnetron led to the creation of smaller systems that had sub-meter resolution. By the end of the war, Germany, Britain, the USSR, Japan and the United States acquired huge land-based radars and sea-based radars inclusive of small air-borne systems. At the end of the war, the use of RAPCON widened and became relevant in various fields including marine navigation, civil aviation, and medicine, radar guns used by police and in meteorology (Devine 09). The major development was the introduction of travelling wave tubes that could be used to produce large amounts of coherent microwaves. Another major development from the post-war period was the establishment of signal delay systems that led to the development of phased array radars and increasing frequencies that could generate higher resolutions.

The history that RAPCON upholds in the evolution of science and technology is argued differently by various authors. Authors like Maurice Ponte believe that RAPCON contributed less to theory that had already been known thanks to ideas from Maxwell and Hertz. Therefore, according to Ponte and other authors, RAPCON never advanced science but instead, it contributed to engineering and technology. The developers of RAPCON in France argued that the basic principle of RAPCON is based on the common knowledge of physicians and technicians who measure effective reality with operational materials. There have also been conflicts and allegations concerning the consequences that result from systems that are built using radar. Apart from the atomic bomb, it is argued that RAPCON led to the creation of alliance by different states that later contributed to the victory experienced in World War II.

In the period of 1931-1939, a variety of technical specialists in the Imperial Navy were interested in finding out how radar could be used to detect aircraft. They decided to consult Professor Yagi who was the Director of the Radar Research Laboratory at Osaka Imperial University. Yagi suggested that they could find out the possibility by examining the Doppler frequency-shift in a reflected signal. Osaka Laboratory was then funded in order for the technique to be investigated. The person who was in charge of the investigation was called Kinjiro Okabe, an inventor of split-anode magnetron, who decided to follow Professor Yagi to Osaka. Theoretically, the analysis suggested that the reflections would increase if only the wavelength was approximated to be of similar size as those of the aircraft structures. Hence, a combination of Yagi antennas and the VHF transmitter were used in the experiment to separate distance. In 1936, Okabe used the RAPCON system to successfully detect an aircraft that was passing. The first demonstration of detecting an aircraft using radar was conducted in Japan using a method known as Doppler-interference method. The success of the experiment was considered an achievement of the radar system. Therefore, Okabe decided to change his research interest from split-anode magnetrons to the use of VHF transmitter and receiver for target detection. However, there was no funding reported for such an operation because the highest officials in the Imperial Navy argued that their enemies would easily intercept radio signals and also the sender’s location might also be exposed especially if they had a similar system.

In the history of the Navy, warships used horns and lights to signal each other at night and when in fog with an objective of avoiding collisions. The current Navy warships are advanced with installation of radar system with new techniques from VHF communications and antennas for direction to avoid and detect collisions at night and in fog. Other inventors like Yoji Ito suggested the use of UHF signal to create a narrow beam that could limit any chance of enemy detection. The microwave system that was also part of the radar system was developed in 1939 to detect and avoid collision, this was after the Imperial Navy provided funding that could be used for preliminary experiments. An equipment was then designed using a 10-GHZ magnetron that had a frequency modulation to detect any reflections from tall buildings or structures that could be at a particular distance. Poor results were obtained and the equipment was later designed with a 1.9-GHZ and power was increased to higher voltage and better results were achieved. In 1940, the RAPCON system with the help of the magnetron apparatus detected clear echoes 10 kilometers from the Tokyo Bay. The system was fully adopted in late 1941 to be used by the Imperial Navy while still under testing. Japan experienced success in their experiments concerning the use of RAPCON to detect collisions in the sea and decided to share their military technological achievement in the late 1940s with Germany (Skloot 219). The Navy were represented by their commander in radar applications and the army were also represented by their commander in radar applications. Japan exchanged their radar-detection techniques with Germany while Germany on the other hand exchanged their pulsed techniques with Japan.

Radar Approach Control System (RAPCON) is capable of providing full control of the airspace to support the requirements that may be needed to control the terminal and Air Traffic Control (ATC). RAPCON is also capable of integrating the ATC systems that are used in theater. RAPCON design makes sure that elements that are scalable and independent can be deployed efficiently to meet the needs of USAF. Radar solutions are also capable of integrating operations that deal with Air-Surveillance Radar (ASR). Radar configurations are installed in various mobile, transport and fixed applications to generate a high level of flexibility. Nevertheless, the radar package meets the deployment flexibility requirements for USAF but using a different mobile ASR which is fully integrated and equipped to operate independently. Radar and non-radar applications are capable of providing control services to transiting airspace and also to control arriving and departing aircraft. RAPCON is also capable of providing radar air traffic control services to aircrafts that operate around military airport terminals. The system also provides Ground Control Approach services (GCA) like radar surveillance in airports and precise radar approach services (Ladson-Billings 11).

In summary, the emerging West and the histories of World War II were twisted together right from the origin of the Western Evolution. Air Traffic Control has experienced a variety of changes and trends all because of the development of the Radar Approach Control System (RAPCON). RAPCON brought significant changes in aircraft control both in equipment and operations as well as on personnel. Northern and Southern states had drifted far apart regarding military technology, and this was after the drafting of the constitution in 1787 (Joseph 18). The North feared with the belief that the South were able to exert pressure towards the complete union with its institution. Due to the demands of war and the threat made towards the union, the federal government decided to bring closer the new country into the Nation. The western development was highly shaped between the period of 1861 and 1877, and this was as a result of the aftermath of the war which was mostly fought on the East side. The following discussion shows how the western expansion of the United States was responsible for causing the Civil War. First of all, slavery was an issue together with its Westward expansion that politicians decided to deal with in the early 1820s of the Missouri Compromise. Missouri Compromise had declared Missouri as a slave State to the Union and a free state was declared to Maine to maintain the balance which was in Congress. Surprisingly, Missouri Compromise did not cater for the new territories which did not appear in the Louisiana Purchase, and so slavery continued with the expansion of the nation. Secondly, as Americans continued to migrate to the west despite the sectional conflict, thousands found themselves entering the territories of Mexico that included New Mexico, Texas and California. James K. Polk who was elected in 1844 as the president of America through his allies enabled Texas to stand as a slave state in 1846 and later Oregon also became a free state when it joined the Union. It is the same Polk who then declared war against Mexico was saying falsely that an army from Mexico had terrorized Americans and shed their blood. This brought about the war in the region which others thought to be very unpopular.</p>