Current Search: Signal processing--Computer simulation (x)
-
-
Title
-
Real time method for remote measurement of compressional wave attenuation.
-
Creator
-
DeBruin, Darryl L., Florida Atlantic University, Schock, Steven G.
-
Abstract/Description
-
An acoustic measurement system is developed to estimate the compressional wave attenuation of marine sediments in real time. A chirp sonar transmits filtered digital reflection data to a signal processing computer that processes the data on an AT&T DSP32C chip. The signal processing computer estimates and displays the center frequency of the processed pulse as it is attenuated by the ocean sediments. Wavelet modelling establishes the relationship between the center frequency shift and...
Show moreAn acoustic measurement system is developed to estimate the compressional wave attenuation of marine sediments in real time. A chirp sonar transmits filtered digital reflection data to a signal processing computer that processes the data on an AT&T DSP32C chip. The signal processing computer estimates and displays the center frequency of the processed pulse as it is attenuated by the ocean sediments. Wavelet modelling establishes the relationship between the center frequency shift and relaxation time, from which the sediment type and compressional wave attenuation are determined. Frequency contours from two different data sites demonstrate that the system is able to reliably estimate sediment type and compressional wave attenuation. Error introduced by noise is below 1% for noise levels less than 0.1 of the normalized processed signal. Random error in the estimates is minimized by determining reliable frequency values and by ensemble averaging the values.
Show less
-
Date Issued
-
1992
-
PURL
-
http://purl.flvc.org/fcla/dt/14824
-
Subject Headings
-
Marine sediments--Acoustic properties, Signal processing--Computer simulation
-
Format
-
Document (PDF)
-
-
Title
-
Estimation of cross range dimensions from a single beam forward look SONAR.
-
Creator
-
Park, Joseph C., Florida Atlantic University, Cuschieri, Joseph M., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
-
Abstract/Description
-
A computer algorithm is developed to provide real-time cross range spatial quantization for a single beam forward look SONAR similar in operation to a typical sidescan SONAR. This involves the computer simulation of return time signals generated by scanning a surface profile. The time signals are normalized with respect to the scanning altitude to simulate the application of a time varying gain, and then are used as input to the surface estimation algorithm. The algorithm requires two time...
Show moreA computer algorithm is developed to provide real-time cross range spatial quantization for a single beam forward look SONAR similar in operation to a typical sidescan SONAR. This involves the computer simulation of return time signals generated by scanning a surface profile. The time signals are normalized with respect to the scanning altitude to simulate the application of a time varying gain, and then are used as input to the surface estimation algorithm. The algorithm requires two time signals acquired from adjacent scanning positions and solves a stereoscopic geometry in arriving at the surface estimate. Final estimates have an error of less than 1% in target height determination within a set range of operation.
Show less
-
Date Issued
-
1989
-
PURL
-
http://purl.flvc.org/fcla/dt/14501
-
Subject Headings
-
Sonar--Computer simulation, Signal processing--Computer simulation, Underwater acoustics--Computer simulation
-
Format
-
Document (PDF)
