Multibeam Sonar Theory of Operation
Multibeam Sonar Theory of Operation
Multibeam Sonar Theory of Operation
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Detection Processing and Range Calculations <strong>Multibeam</strong> <strong>Sonar</strong> <strong>Theory</strong> <strong>of</strong> <strong>Operation</strong><br />
The effect <strong>of</strong> rotation about each <strong>of</strong> these directions is illustrated in Figure Chapter 4 - -14. The<br />
degree <strong>of</strong> rotation is measured as an angle.<br />
Figure Chapter 4 - -14: Roll, Pitch, and Yaw Angles<br />
Between time slices, the ship moves in each <strong>of</strong> these six different ways: surge, sway, and heave<br />
<strong>of</strong> its center <strong>of</strong> mass, and roll, pitch, and yaw about its center <strong>of</strong> mass. In other words, the ship has<br />
six degrees <strong>of</strong> freedom to its motion. The SEA BEAM 2100 accepts input from two<br />
measurement systems that constantly monitor all six degrees <strong>of</strong> freedom:<br />
• The Navigation instrument records the position <strong>of</strong> the ship (latitude, longitude, and heading at<br />
time <strong>of</strong> ping) associated with surge, sway, and yaw motions.<br />
• The Vertical Reference Unit (VRU) records roll, pitch, and heave information.<br />
Of these instrument readings, the roll and pitch values from the VRU are necessary for per-timeslice<br />
processing. The VRU, however, does not make measurements with the frequency <strong>of</strong> the<br />
time slices. Obtaining unique and accurate values that correspond to the times <strong>of</strong> the time slices<br />
requires linear interpolations from the two nearest VRU measurements.<br />
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No portion <strong>of</strong> this document may be reproduced without the expressed written permission <strong>of</strong> L-3 Communications SeaBeam Instruments