amplitude

amplitude

1. Astronomy the angular distance along the horizon measured from true east or west to the point of intersection of the vertical circle passing through a celestial body

2. Maths (of a complex number) the angle that the vector representing the complex number makes with the positive real axis. If the point (x, y) has polar coordinates (r, θ), the amplitude of x + iy is θ, that is, arctan y/x

3. Physics the maximum variation from the zero or mean value of a periodically varying quantity

Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

amplitude

1. Symbol: δm . The difference between the maximum and minimum magnitudes of a variable star, i.e. the range in magnitude of the star. The amplitude of pulsating variables is related to the logarithm of the period.

2. The maximum instantaneous deviation of an oscillating quantity from its average value.

Collins Dictionary of Astronomy © Market House Books Ltd, 2006

amplitude

[′am·plə‚tüd]

(astronomy)

The range in brightness of a variable star, usually expressed in magnitudes.

(mathematics)

The angle between a vector representing a specified complex number on an Argand diagram and the positive real axis. Also argument.

(navigation)

Angular distance north or south of the prime vertical; the arc of the horizon, or the angle at the zenith between the prime vertical and a vertical circle, measured north or south from the prime vertical to the vertical circle.

(physics)

The maximum absolute value attained by the disturbance of a wave or by any quantity that varies periodically.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

amplitude

Of oscillation or vibration, the maximum displacement from the mean position.

McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.

amplitude

i. The amplitude of a wave is the maximum displacement, or the maximum value, it attains from its mean position during a cycle. It is both positive and negative. With sound waves, the greater the amplitude, the louder is the sound.
ii. Angular distance north or south of the prime vertical; the arc of the horizon or the angle at the zenith between the prime vertical and a vertical circle, measured north or south from the prime vertical circle. The term is used customarily only to refer to bodies whose centers are on the celestial horizon and is prefixed “E” or “W” as the body is rising or setting, respectively, and suffixed “N” or “S” to agree with the declination.

An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved

amplitude

The strength or volume of a signal, usually measured in decibels. See wavelength.

Amplitude

The amplitude is the power of a signal. The greater the amplitude, the greater the energy carried.

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