spherical polygon

Any part of a spherical surface that is bounded by arcs of three or more great circles.

spherical powder

A powder consisting of globular-shaped or round particles.

spherical sailing, circular sailing

1. Any of the sailing computation methods which are used to solve the problems of course, distance, difference of latitude, difference of longitude, and departure which take into account the spherical or spheroidal shape of the earth.

2. A method of navigation in which the curvature of the earth is taken into consideration.

spherical sector

A solid formed by rotating a sector of a circle around a diameter of the circle.

The diameter may contain one of the radii bounding the circular sector or it may lie outside the circular sector.

spherical separator

A ball-shaped vessel used for gas and oil separation.

A spherical separator can be used for two-phase or three-phase separation purposes.

Spherical separators are less efficient than either horizontal or vertical cylindrical separators and are seldom used; however, their compact sizes and ease of transportation have made them suitable for crowded processing areas.

spherical triangle

1. A spherical polygon that has three sides with three intersecting great circular arcs.

2. A triangle the three sides of which are arcs of great circles intersecting.

spherical trigonometry

1. Trigonometry that deals with spherical triangles.

2. The study of spherical triangles from the viewpoints of angles, lengths, and areas.

3. A branch of trigonometry concerned with the measurements of the angles and sides of spherical triangles.

spherical wave

A wave generated from a point source; such as, that generated by an underground explosion.

Typical seismic sources; such as, vibrators and air-gun arrays emit elastic waves that are assumed to be spherical waves.

spherical weathering, spheroidal weathering, concentric weathering

1. The chemical weathering of blocks of rock so that they take on a more rounded shape; such as rounded boulders that help to create domed monoliths.

2. Chemical weathering in which concentric or spherical shells of decayed rock are successively separated from a block of rock.

It commonly results in the formation of a rounded boulder of decomposition.

spherical wedge

1. The portion of a sphere bounded by two semicircles and a lune (the surface of the sphere between the semicircles).

2. That part of a sphere included between two planes which intersect in a diameter.

spherical-coordinate robot, spherical robot

A robot in which the degrees of freedom of the manipulator arm are defined primarily by spherical coordinates or the coordinates of a sphere.

spherical-coordinate system

A three-dimensional system for locating points in space b means of a radius vector and two angles measured from the center of a sphere with respect to two arbitrary, fixed, perpendicular directions.

spherical-earth attenuation

In electromagnetism, attenuation over an imperfectly conducting spherical earth in excess of that over a perfectly conducting plane.

The term *attenuation* refers to the reduction with distance from the source of the intensity of an electromagnetic signal propagating through the atmosphere caused by the interaction of the signal with gaseous constituents of the atmosphere, aerosols, or hydrometeors.

It also includes the reduction of intensity of a radiation as it passes through a medium and it includes reductions due to both absorption and scattering.

spherical-earth factor

The ratio of the electric field strength in a wave that would result from propagation over an imperfectly conducting spherical earth to that which would result from propagation over a perfectly conducting plane.

sphericity

1. The state of being spherical; a round form; roundness; as, the sphericity of the planets, or of a drop of water.

2. The degree to which a shape is spherical or approaches that of a sphere.

Related **ball, sphere**-word units:
**glob-, glom-**;
**hemoglobin-**.