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 />
Figure Chapter 4 - -20: Finding the Roll-Adjusted Angles Nearest the Beam Angle<br />
Both θ n and θ n+1 have amplitude values associated with them, A n and A n+1 . They will also have<br />
complex beam patterns, which tell you their response to echoes as a function <strong>of</strong> angle from their<br />
axis (see Figure Chapter 4 - -21). For each <strong>of</strong> these two beams, you can calculate a relative<br />
“weight” based on the response level <strong>of</strong> their beam pattern at the angle between them and θ B (θ B -<br />
θ n , or θ n+1 - θ B ). From their amplitudes A n and A n+1 and these computed weights, you can<br />
interpolate a new amplitude A B , which is the amplitude <strong>of</strong> the echo received from direction θ B .<br />
Thus, you are obtaining the echo returns in a beam whose axis is always fixed with reference to<br />
earth. This processing is repeated for each time slice.<br />
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