Minutes (angular)
Abbreviation/Symbol:
- MOA
- arcmin
Unit of:
- Angle
Worldwide use:
- Global
Description:
A minute of arc, also known as arcminute is an unit of angle equal to 1⁄60 of a degree, or 1⁄21600 of a circle . It is used in fields that involve very small angles such as optometry, navigation and marksmanship.
Origin:
The milliradian ('mil') was first used in the 19th Century by Charles-Marc Dapples, who was a professor at the University of Lausanne. At the beginning of World War I, France started experimenting with using milliradians on artillery sights instead of decigrades (circle/4000). They were used by France alongside decigrades during World War I. The United States, who copied many French artillery practices, also adopted mils.
Usage context:
Along with the degree,arc minutes and seconds are the most commonly used angular measurement units
Component units:
- An arc minute can be divided into 60 arc seconds
Multiples:
- There are 60 arc minutes in a degree and 21,600 arc minutes in a circle.
