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Eng ID Term Definition
4921
spatial
(adj.). Pertaining to or limited by space.
4922
special mark
In the IALA Maritime Buoyage System, a special mark indicates an area or FEATURE referred to in NAUTICAL documents; it is not primarily inte... more
In the IALA Maritime Buoyage System, a special mark indicates an area or FEATURE referred to in NAUTICAL documents; it is not primarily intended to assist NAVIGATION.
4923
special purpose map
See MAP.
4924
specific gravity
The ratio of the density of a sub­stance at a given temperature and the density of some other substance used as a STANDARD. For liquids and ... more
The ratio of the density of a sub­stance at a given temperature and the density of some other substance used as a STANDARD. For liquids and solids, the STANDARD assumed is the density of distil­led water at 4°C.
4925
spectroscope
An optical instrument for forming SPEC­TRA. It is very useful in studying the characteris­tics of CELESTIAL BODIES.
4926
spectrum
(pl. spectra). A series of IMAGES formed when a BEAM of RADIANT ENERGY is separated into its various WAVE LENGTH components, as when a BEAM ... more
(pl. spectra). A series of IMAGES formed when a BEAM of RADIANT ENERGY is separated into its various WAVE LENGTH components, as when a BEAM of white light is refracted and dispersed by a prism. The entire RANGE of electromagnetic RADIATIONS, or any part of it used for a specific purpose, as the RADIO SPECTRUM (10 kilohertz to 300,000 MEGAHERTZ).
4927
specular reflection
The type of reflection, in optics or microwave theory, characteristic of a highly polis­hed plane surface from which all rays are reflected ... more
The type of reflection, in optics or microwave theory, characteristic of a highly polis­hed plane surface from which all rays are reflected at an angle equal to the angle of incidence.
4928
speed
Rate of motion. The terms speed and VELOCITY are often used interchan­geably, but speed is a scalar, having magnitude only, while VELOCITY i... more
Rate of motion. The terms speed and VELOCITY are often used interchan­geably, but speed is a scalar, having magnitude only, while VELOCITY is a vector quan­tity, having both magnitude and direction. Speed may either be the ship's speed through water, or the SPEED MADE GOOD over ground.
4929
speed: angular
Change of direction per unit time. Also called angular rate or angular velocity.
4930
speed: ground
See GROUND SPEED.
4931
speed: linear
Rate of motion in a straight line.
4932
speed: relative
See RELATIVE MOTION.
4933
speed line
A LINE OF POSITION approximately perpendi­cular to the COURSE.
4934
speed made good
The actual velocity of the ship along a course measured in relation to the ocean bottom or to fixed objects ashore.
4935
speed of lens
See APERTURE: RELATIVE.
4936
speed of propagation
The speed with which waves of energy travel through or along a medium other than a specially constructed path.
4937
speed of relative movement
See RELATIVE MOTION.
4938
speed of sound
The SPEED OF PROPAGATION of sound waves .
4939
speedometer
An ODOMETER recording the SPEED of a craft by a process of differentiation.
4940
speed scale
See SCALE.