Data

Data (/ˈdeɪtə/ DAY-tə, /ˈdætə/ DA-tə, or /ˈdɑːtə/ DAH-tə) is a set of values of qualitative or quantitative variables; restated, pieces of data are individual pieces of information. Data is measured, collected and reported, and analyzed, whereupon it can be visualized using graphs or images. Data as a general concept refers to the fact that some existing information or knowledge is represented or coded in some form suitable for better usage or processing.

Raw data, i.e. unprocessed data, is a collection of numbers, characters; data processing commonly occurs by stages, and the "processed data" from one stage may be considered the "raw data" of the next. Field data is raw data that is collected in an uncontrolled in situ environment. Experimental data is data that is generated within the context of a scientific investigation by observation and recording.

The Latin word "data" is the plural of "datum", and still may be used as a plural noun in this sense. Nowadays, though, "data" is most commonly used in the singular, as a mass noun (like "information", "sand" or "rain").

Tornado Alley

Tornado Alley is a colloquial term for the area of the United States (or by some definitions extending into Canada) where tornadoes are most frequent. The term was first used in 1952 as the title of a research project to study severe weather in parts of Texas, Oklahoma, Kansas, South Dakota, Iowa, Missouri, New Mexico, Colorado, North Dakota, and Minnesota only. It is largely a media driven term although tornado climatologists distinguish peaks in activity in various areas and storm chasers have long recognized the Great Plains tornado belt.

Although the boundaries of Tornado Alley are not clearly defined, its core extends from northern Texas, Oklahoma, Kansas, into Nebraska. Some research suggests that tornadoes are becoming more frequent in the northern parts of Tornado Alley where it reaches the Canadian prairies.

Active tornado regions have also been discovered in other areas of the world, such as in parts of Europe and especially in the Pampas lowlands of Argentina extending into adjacent areas of Paraguay and extreme southern Brazil. The Pampas has a high consistency of tornadoes, whereas Bangladesh and adjacent East India have the highest frequency of violent tornadoes outside the central and southern US.

Pulse-Doppler radar

A pulse-Doppler radar is a radar system that determines the range to a target using pulse-timing techniques, and uses the Doppler effect of the returned signal to determine the target object's velocity. It combines the features of pulse radars and continuous-wave radars, which were formerly separate due to the complexity of the electronics.

Pulse-Doppler systems were first widely used on fighter aircraft starting in the 1960s. Earlier radars had used pulse-timing in order to determine range and the angle of the antenna (or similar means) to determine the bearing. However, this only worked when the radar antenna was not pointed down; in that case the reflection off the ground overwhelmed any returns from other objects. As the ground moves at the same speed but opposite direction of the aircraft, Doppler techniques allow the ground return to be filtered out, revealing aircraft and vehicles. This gives pulse-Doppler radars "look-down/shoot-down" capability. A secondary advantage in military radar is to reduce the transmitted power while achieving acceptable performance for improved safety of stealthy radar.

100 kilometres

A length of 100 kilometers (about 62 English miles), as a rough amount, is relatively common in measurements on Earth and for some astronomical objects. It is the altitude at which the FAI defines spaceflight to begin. To help compare orders of magnitude, this page lists lengths between 100 and 1,000 kilometres (10⁵ and 10⁶metres).

Distances shorter than 100 kilometres

Conversions

A distance of 100 kilometres is equal to about 62 miles (or 62.13711922 miles).

Human-defined scales and structures

New Zealand

New Zealand (/njuːˈziːlənd/ new-ZEE-lənd, Māori: Aotearoa [aɔˈtɛaɾɔa]) is an island country in the southwestern Pacific Ocean. The country geographically comprises two main landmasses – that of the North Island, or Te Ika-a-Māui, and the South Island, or Te Waipounamu – and numerous smaller islands. New Zealand is situated some 1,500 kilometres (900 mi) east of Australia across the Tasman Sea and roughly 1,000 kilometres (600 mi) south of the Pacific island areas of New Caledonia, Fiji, and Tonga. Because of its remoteness, it was one of the last lands to be settled by humans. During its long isolation, New Zealand developed a distinctive biodiversity of animal, fungal and plant life. The country's varied topography and its sharp mountain peaks, such as the Southern Alps, owe much to the tectonic uplift of land and volcanic eruptions. New Zealand's capital city is Wellington, while its most populous city is Auckland.

Somewhere between 1250 and 1300 CE, Polynesians settled in the islands that were to become New Zealand, and developed a distinctive Māori culture. In 1642, Abel Tasman, a Dutch explorer, became the first European to sight New Zealand. In 1840, representatives of the British Crown and Māori Chiefs signed the Treaty of Waitangi, making New Zealand a British colony. Today, the majority of New Zealand's population of 4.5 million is of European descent; the indigenous Māori are the largest minority, followed by Asians and Pacific Islanders. Reflecting this, New Zealand's culture is mainly derived from Māori and early British settlers, with recent broadening arising from increased immigration. The official languages are English, Māori and New Zealand Sign Language, with English predominant.