The Mount Fuji Radar System is a historic

weather radar A weather radar, also called weather surveillance radar (WSR) and Doppler weather radar, is a type of radar used to locate precipitation (meteorology), precipitation, calculate its motion, and estimate its type (rain, snow, hail etc.). Modern w ...

system located on the summit of

Mount Fuji is an active stratovolcano located on the Japanese island of Honshu, with a summit elevation of . It is the highest mountain in Japan, the second-highest volcano on any Asian island (after Mount Kerinci on the Indonesian island of Sumatra), a ...

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

Construction

The installation was completed on August 15, 1964, and is now recorded on the

list of IEEE Milestones #REDIRECT List of IEEE Milestones {{R from merge, Timeline of electrical and electronic engineering#List of IEEE Milestones ...

electrical engineering Electrical engineering is an engineering discipline concerned with the study, design, and application of equipment, devices, and systems that use electricity, electronics, and electromagnetism. It emerged as an identifiable occupation in the l ...

. When first built, the Mount Fuji Radar System was the world's highest weather radar (elevation ), and could observe major weather phenomena, such as destructive

typhoon A typhoon is a tropical cyclone that develops between 180° and 100°E in the Northern Hemisphere and which produces sustained hurricane-force winds of at least . This region is referred to as the Northwestern Pacific Basin, accounting for a ...

s, at a range of more than . It was designed by the

Japan Meteorological Agency The Japan Meteorological Agency (JMA; ''気象庁, Kishō-chō'') is a division of the Ministry of Land, Infrastructure, Transport and Tourism dedicated to the Scientific, scientific observation and research of natural phenomena. Headquartered ...

and built by Mitsubishi Electric Corporation.

Technology

The system is notable for its advances in weather radar technology,

remote control A remote control, also known colloquially as a remote or clicker, is an consumer electronics, electronic device used to operate another device from a distance, usually wirelessly. In consumer electronics, a remote control can be used to operat ...

, and difficulty of construction, as it required the transport and assembly of some 500 tons of material during mountain's short summer. It operated at a frequency of , with output power of 1500

kilowatt The watt (symbol: W) is the unit of Power (physics), power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantification (science), quantify the rate of Work ...

s, and a pulse width of 3.5

microsecond A microsecond is a unit of time in the International System of Units (SI) equal to one millionth (0.000001 or 10−6 or ) of a second. Its symbol is μs, sometimes simplified to us when Unicode is not available. A microsecond is to one second, ...

s. Its antenna was a circular dish, 5 meters in diameter, of parabolic shape, rotating at either 3 or 5 revolutions per minute, and housed within a 9-meter

radome A radome (a portmanteau of "radar" and "dome") is a structural, weatherproof enclosure that protects a radar antenna (radio), antenna. The radome is constructed of material transparent to radio waves. Radomes protect the antenna from weathe ...

Use after decommission

The system was decommissioned in 1999, as it was superseded by

weather satellite A weather satellite or meteorological satellite is a type of Earth observation satellite that is primarily used to monitor the weather and climate of the Earth. Satellites are mainly of two types: polar orbiting (covering the entire Earth asyn ...

s. The dome, radar dish and support equipment were relocated to a purpose-built museum in

Fujiyoshida is a Cities of Japan, city located in Yamanashi Prefecture, Japan. , the city had an estimated population of 48,782 in 19,806 households and a population density of 400 persons per km2. The total area of the city is . Geography Fujiyoshida lie ...

, Yamanashi in 2001. It was replaced by an automated weather system on October 1, 2008.https://www.gov-online.go.jp/eng/publicity/book/hlj/html/201801/201801_09_en.html

Construction

Technology

Use after decommission

References

Further reading