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This paper presents a technique by which a low-cost, minimally-equipped unmanned underwater vehicle (UUV) can localize itself while submerged using acoustic emissions of transiting sources of opportunity (SOOs). The technique provides a bounded estimate of the UUV position and is intended to supplement the on-board Inertial Navigation System (INS). The technique exploits two physical phenomena, the...
This paper presents a technique for extending the bandwidth of chirped active sonar signals. Bandwidth synthesis (BWS) results in improved range resolution, increased signal-to-noise ratio (SNR) and reduced fading due to delay-spread multipath. The approach demonstrated uses a low-order autoregressive (AR) process to model de-chirped segments of the received signal, which are then extrapolated using...
Doppler-sensitive waveforms are often used in shallow water to mitigate high reverberation levels. This paper compares three Doppler sensitive sonar waveforms including coherently-processed pulse trains, uniform frequency combs, and nonuniform co-prime frequency combs in terms of their delay-Doppler responses. It is shown that the use of comb waveforms can reduce Doppler sidelobes without trading...
This paper presents an active sonar waveform that achieves range-Doppler performance similar to a uniform frequency comb, but uses far fewer tones to do so. The trade-off for this reduction in occupied bandwidth is a larger bandwidth extent. Co-prime comb signals consist of tones at non-uniformly spaced frequencies according to a 2-level nested co-prime array structure. Specialized non-matched filter...
Research Experience for Undergraduates (REU) programs are research projects funded by the U.S. National Science Foundation. They are typically completed during the summer after a student?s sophomore or junior year. They usually last eight to 12 weeks and fund a small research project at research-oriented universities. REUs are usually targeted toward underrepresented groups and students from smaller,...
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