Sonardyne 8142-000-01, Руководство пользователя

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User Manual: Generic Section
Section: Introduction 0-4
Revision: 00 Page 13 of 21
Sonardyne Systems
Term Definition
Vertical Reference Gyroscope (VRG) A gyroscopically stabilised VRU.
Vertical Reference Unit (VRU) Measures the instantaneous roll and pitch of a vessel
Vessel A body floating in the sea with at least part of it penetrating the
surface. It is free to move and rotate relative to the seabed.
Signal Processing and Communications Terms
Term Definition
Bore-Sight The axis about which the transducer maximum power gain is
being directed.
Capture Area The effective aperture size of the array. It is directly related to
the array gain.
Configuration Status (CS)
Directivity Index This is the ratio of the radiation intensity in the direction of
interest compared with an isotropic radiator.
False Alarm An invalid signal which has satisfied all of the detection criteria,
and the detection process incorrectly declares a valid signal.
False Alarm Number Predicts the average number of possible decisions between
false alarms
False Alarm Probability The resultant probability of all the false alert probabilities.
False Alarm Rate Predicts the number of false alarms that will occur in a
specified time.
False Alert An invalid signal has satisfied one detection criteria and the
detection process incorrectly declares a valid signal.
False Alert Rate Predicts the number of false alerts that will occur in a specified
time.
Front to Back Ratio for a Transducer Is the ratio of power transmitted in the forward hemisphere of
the polar diagram to that transmitted in the reverse hemisphere
of the polar diagram.
Kalman Filter An adaptive filter that provides optimum filtering of a signal that
has been subjected to a non-stationery environment (i.e. when
the data is significantly changing during the filter convergence
time).
Signal to Noise Ratio (SNR) This is the ratio of the signal power to noise power in unit
bandwidth generally quoted in dB.