A combinatorial approach to automated LOFARGRAM analysis
Brahosky, Vance A.
MetadataShow full item record
This thesis examines the combination of three algorithms: Graph Theoretic Tracker (GTT), Hough Transform, and Heuristic Search to enhance the detection of spectral tracks of underwater targets in LOFARGRAMS. Previous studies examined these algorithms separately. Here, GTT is used as a pre-processor of the LOFARGRAM display data to locat optimum paths of signals through noise. The line tonals in the output image from GTT are then manipulated by the Hough Transform into clusters of points in parameter space. A Heuristic Search sorting technique is employed to determine cluster centers. These cluster centers are then reconstructed back into line tonals using the inverse Hough Transform formula. The results of this thesis show improvements by taking the Hough Transform of the original LOFARGRAM masked by the output of GTT. The effect of background noise is offset by the accumulation in the parameter space. Subsequently, the recovery of desired tonals is improved.
RightsThis publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
Showing items related by title, author, creator and subject.
Rocha Pitta, Jorge Antonio Fernandes da. (Monterey, California. Naval Postgraduate School, 1995-03);The analysis of transient signals using classical techniques is frequently not satisfactory. The Fourier analysis is based on stationarity of the signaL and transients are nonstationary. A new technique for the analysis ...
Retsas, Ioannis. (Monterey California. Naval Postgraduate School, 2002-03);Digital watermarking is a highly evolving field, which involves the embedding of a certain kind of information under a digital object (image, video, audio) for the purpose of copyright protection. Both the image and the ...
Chua, Cheng Lock Charles (Monterey California. Naval Postgraduate School, 2006-12);SAR has traditionally been performed using high-range resolution data. This thesis is a proof-of-concept that the imaging process can be performed using high-doppler resolution data. The system requires a simple continuous ...