Glossary
dielectric constant (DK): the ability of a dielectric to store electrical potential energy under the influence of an electric field. Also known as Relative Permittivity. An increase in the dielectric constant is directly proportional to an increase in signal amplitude. The value is
usually given relative to a vacuum /dry air: the dielectric constant of air is 11.
echo: a signal that has been reflected with sufficient magnitude and delay to be perceived in some manner as a signal distinct from that directly transmitted. Echoes are frequently measured in decibels relative to the directly transmitted signal.
echo confidence: the recognition of the validity of the echo. A measure of echo reliability.
Echo Marker: a marker that points to the processed echo.
Echo Processing: the process by which the radar unit determines echoes.
Echo Strength: describes the strength of the selected echo in dB above 1 ∝V rms.
Echo Profile: a graphical display of a processed echo.
emission cone: the extension of the antenna’s angle
false echo: any echo which is not the echo from the desired target. Generally, false echoes are created by vessel obstructions.
frequency: the number of periods occurring per unit time. Frequency may be stated in cycles per second.
hertz (Hz): unit of frequency, one cycle per second. 1 Gigahertz (GHz) is equal to 109 Hz.
horn antenna: a conical,
inductance: the property of an electric circuit by virtue of which a varying current induces an electromotive force in that circuit or in a neighboring circuit. The unit is a Henry.
microwaves: the term for the electromagnetic frequencies occupying the portion of the radio frequency spectrum from 1 GHz to 300 GHz.
multiple echoes: secondary echoes that appear as double, triple, or quadruple echoes in the distance from the target echo.
Near Range: a blind zone extending away from the reference point plus any additional shield length.The instrument is programmed to ignore this zone.
nozzle: a length of pipe mounted onto a vessel that supports the flange.
parameters: in programming, variables that are given constant values for specific purposes or processes.
polarization: the property of a radiated electromagnetic wave describing the
polarization error: the error arising from the transmission or reception of an electromagnetic wave having a polarization other than that intended for the system.
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