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Storm spotting is a form of weather spotting in which observers watch for the approach of severe weather, monitor its development and progression, and actively relay their findings to local authorities.〔(【引用サイトリンク】title=Tornado and Thunderstorm Spotting, Getting Started )〕 == History == Storm spotting developed in the United States during the early 1940s. A joint project between the military and the weather bureau saw the deployment of trained military and aviation lightning spotters in areas where amunitions for the war were manufactured. During 1942, a serious tornado struck a key operations center in Oklahoma and another tornado on May 15, 1943 destroyed parts of the Fort Riley military base located in Kansas. After these two events and a string of other tornado outbreaks, spotter networks became commonplace, and it is estimated that there were over 200 networks by 1945.〔(【引用サイトリンク】title=Storm Spotting and Public Awareness )〕 Their mandate had also changed to include reporting all types of active or severe weather; this included giving snow depth and other reports during the winter as well as fire reports in the summer, along with the more typical severe weather reports associated with thunderstorms. However, spotting was still mainly carried out by trained individuals in either the military, aviation, or law enforcement fields of service. It was not until 1947 that volunteer spotting, as it exists today, was born. After a series of vicious tornado outbreaks hit the state of Texas in 1947, the state placed special emphasis on volunteer spotting, and the local weather offices began to offer basic training classes to the general public.〔 Spotting required the delivery of timely information so that warnings could be issued as quickly as possible, thus civilian landline phone calls and amateur radio operators provided the most efficient and fastest means of communication. While phone lines were reliable to a degree, a common problem was the loss of service when an approaching storm damaged phone lines in its path. This eventually led to amateur radio becoming the predominant mean of communication and resulted in the installation of special amateur radio work zones within local weather offices. Volunteer spotters would come into the local office and run a radio net from within, directly relaying information to meteorologists. The 1950s saw the deployment of the first dedicated weather radars in the United States, and by this time, civilian spotter networks were commonplace. The new reflectivity-only radars provided meteorologists with basic information and helped identify potentially severe storms, but due to the nature of weather radar, most precipitation was detected at a height of 1 kilometer or more above the ground. Ultimately, the radar cannot see what exactly occurs at the surface of the earth, and storm spotters now correlated ground truthing with radar signatures. New spotter technologies and training techniques have been developing since the 1960s. Prior to the 1960s, the vast majority of amateur radio communication relied on AM-modulated signals and the use of simplex. It was not uncommon for spotters to hear the distant net control station and not hear other mobile or base stations which were much closer. After 1960, amateurs adopted the use of FM repeaters which operated in the VHF spectrum. The use of FM repeaters was a huge advancement for storm spotters; spotters could now hear each other regularly. The low noise floor and greatly improved audio quality meant much better signal reception for all stations. By the 1970s, nearly all spotter radio activity consisted of half-duplex FM repeater use.〔(Amateur Radio History )〕 The next major technology to aid spotters was the development of the cell phone in the late 1970s and early 1980s. It was thsn possible for non-amateur radio operators to directly report severe weather. Storm spotting became more popular with the public during the late 1980s and early 1990s. During this period, a number of NSSL (National Severe Storms Laboratory) projects were carried out, some of which were documented and broadcast on television in a number of specials.〔(Amazon.com: Nova: Tornado: Video: Nova )〕 Spotters and their actions were attributed to saving lives as well as aiding university research groups, who would drop sensors such as TOTO in the path of tornadoes and at times fire rocketsondes directly at or very close to tornadoes.〔(Microsoft Word - edo.doc )〕 At about the same time, early storm chasers were popularized and associated with spotters. It is believed this association is what has led many in the present era to associate storm chasers and storm spotters as carrying out the same actions or having the same goals. 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「Storm spotting」の詳細全文を読む スポンサード リンク
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