UACE2017 Proceedings: Ambiguity functions wide band and narrow band approximations and high duty cycle sonars

Session:
Large Time-Bandwidth acoustic signals for target detection and tracking
Paper:
Ambiguity functions wide band and narrow band approximations and high duty cycle sonars
Author(s):
Paul Hines, Stefan Murphy, Jeffrey Bates, Matthew Coffin,
Abstract:
There is considerable interest in using high duty cycle (HDC) waveforms in modern active sonars. Furthermore, the increase in signal energy that results from using HDC pulses enables wider frequency bandwidths to be transmitted, since there is a reduced requirement to use a high-Q transducer to maximize energy. The combination of high duty cycle and wide frequency band can lead to very large time-bandwidth (TB) products. Although this can provide high coherent gains out of the matched filter, it can also lead to systems that are hypersensitive to both Doppler and range accuracy. Since many sonar performance models employ approximations, it seems germane to examine the validity of some common approximations in the context of these pulses, and to compare the results to theory. The theoretical work is complemented with measurements taken during the Littoral Continuous Active Sonar (LCAS) Multi-National Joint Research Project (MN-JRP) off the coast of La Spezia Italy in October of 2015.
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