(Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1988-08)
Nicholson, John W.
This thesis presents the results of several experiments performed on side scan sonar equipment
and imagery with the aim of characterizing the acoustic variability of side scan sonar imagery
and applying this information to image rectification and registration. A static test tank
experiment is presented which analyzes the waveform, power spectral density, and temporal
variability of the transmitted waveform. The results of a second static experiment conducted
from the Woods Hole Oceanographic Institution Pier in Woods Hole, Massachusetts permit
determination of the distribution and moments of intensity fluctuations of echoes from objects
imaged in side scan sonograms. This experiment also characterizes temporal and spatial
coherence of intensity fluctuations. A third experiment is presented in which a side scan
sonar towfish images the bottom adjacent to the pier while running along an underwater
track which reduces towfish instability. Imagery from this experiment is used to develop
a rectification and registration algorithm for side scan sonat images. Preliminary image
processing is described and examples presented, followed by favorable results for automated
image rectification and registration.