Square degree

Square degree

A square degree (denoted deg²) is a non-SI unit measure of solid angle. Just as degrees are used to measure parts of a circle, square degrees are used to measure parts of a sphere. Analogous to one degree being equal to pi/180 radians, a square degree is equal to (pi/180)^2 or about 1/3283 steradian. The number of square degrees in a whole sphere is 4 pi (180/pi)^2 = 129 600/pi or approximately 41,253 deg².

For example, observed from the surface of the Earth, the Moon has a diameter of approximately 0.5°, so it covers an solid angle of approximately 0.20 deg², which is 4.8×10-6 of the total sky sphere.


Wikimedia Foundation. 2010.

Игры ⚽ Нужно сделать НИР?

Look at other dictionaries:

  • square degree — (sq deg)    a unit of solid angle measure. Since one degree of ordinary angle measure equals pi/180 radians, one square degree is defined to be (pi/180)2 = 0.000 304 617 4 steradian. There are 4·1802/(pi) = 129 600/(pi) = 41 252.961 25 square… …   Dictionary of units of measurement

  • Degree (angle) — One degree (shown in red) and ninety degrees (shown in blue) This article describes the unit of angle. For other meanings and some specific usages, see degree. A degree (in full, a degree of arc, arc degree, or arcdegree), usually denoted by °… …   Wikipedia

  • Degree of a polynomial — The degree of a polynomial represents the highest degree of a polynominal s terms (with non zero coefficient), should the polynomial be expressed in canonical form (i.e. as a sum or difference of terms). The degree of an individual term is the… …   Wikipedia

  • Square (geometry) — In Euclidean Geometry geometry, a square is a regular polygon with four equal sides. In Euclidean geometry, it has four 90 degree angles. A square with vertices ABCD would be denoted squarenotation|ABCD. Classification A square (regular… …   Wikipedia

  • Square-free polynomial — In mathematics, a square free polynomial is a polynomial with no square factors, i.e, f in F [x] is square free if and only if b^2 mid f for every b in F [x] with non zero degree. This definition implies that no factors of higher order can exist …   Wikipedia

  • Square measure — measure meas ure (m[e^]zh [ u]r; 135), n. [OE. mesure, F. mesure, L. mensura, fr. metiri, mensus, to measure; akin to metrum poetical measure, Gr. me tron, E. meter. Cf. {Immense}, {Mensuration}, {Mete} to measure.] 1. A standard of dimension; a… …   The Collaborative International Dictionary of English

  • Degree matrix — In the mathematical field of graph theory the degree matrix is a diagonal matrix which contains information about the degree of each vertex. It is used together with the adjacency matrix to construct the Laplacian matrix of a graph. Definition… …   Wikipedia

  • Square (astrological aspect) — In astrology, a square is an astrological aspect is formed when two planets or other heavenly bodies form a 90 degree angle to each other. For example, if the Sun is posited in 10 degrees Aquarius and Neptune is posited in 10 degrees Scorpio then …   Wikipedia

  • Square orthobicupola — Infobox Polyhedron with net Polyhedron Type=Johnson J 27 J28 J29 Face List=8 triangles 2+8 squares Edge Count=32 Vertex Count=16 Symmetry Group=D4h Vertex List=8(32.42) 8(3.43) Dual= Property List= In geometry, the square orthobicupola is one of… …   Wikipedia

  • Degree of truth — In standard mathematics, propositions can typically be considered unambiguously true or false. For instance, the proposition zero belongs to the set { 0 } is regarded as simply true; while the proposition one belongs to the set { 0 } is regarded… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”