Traditional narrow-band synthetic aperture sonar (SAS) suffers from reduced along-track resolution and reduced pulse repetition as the speed of the sonar platform increases. Wideband SAS systems offer a method for reducing these undesirable effects at the expense of increased system complexity. Most recently, Gough and Hayes have demonstrated the performance of a wideband SAS that uses continuous-tone frequency modulation (CTFM) as the transmitted waveform [J. Acoust. Soc. Am. 86 (1989)]. This paper presents the system design for a wideband SAS that uses binary phase-shift keyed (BPSK) modulation for the transmitted waveform. In addition to being wideband (like CTFM), the BPSK signal offers unique advantages over CTFM in active SAS systems. In the system presented here, maximal-length pseudo-random (or pseudo-noise, PN) sequences are used to encode the BPSK waveform, offering the ability to transmit uniquely different coded waveforms in rapid succession, hence providing a higher spatial sampling rate than is achievable with uncoded waveforms. In addition to the system design, computer simulations are presented that compare images generated by narrow-band, CTFM, and PN-BPSK processing. Tradeoffs between image quality versus processing complexity are discussed.

This research has investigated the effectiveness of the proposed security plan for the ONP-300 through the use of a simulation software developed by ARES Security Corporation which evaluates the plant design and security plan. This paper updates the security strategy in the earlier 2016 paper (ICONE24-61029, Charlotte, NC, Kindfuller et. al.) with the following significant additions: a modification of the plant design for security optimization, changes in the guard force based on simulations, placement of the protective barrier to prevent damage from ship explosions, and establishment of the shore station guard force, response team and key facilities.

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