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Updated: Jun 6, 2026

A Stable Phantom Material for Optical and Acoustic Imaging
Published on: June 16, 2023
Stretched-exponential Doppler spectra in underwater acoustic communication channels
P A van Walree1, T Jenserud, R Otnes
1Norwegian Defence Research Establishment FFI, PO Box 115, Horten, Vestfold NO-3191, Norway. paul.vanwalree@ffi.no
Abstract:
The theory of underwater sound interacting with the sea surface predicts a Gaussian-spread frequency spectrum in the case of a large Rayleigh parameter. However, recent channel soundings reveal more sharply peaked spectra with heavier tails. The measured Doppler spread increases with the frequency and differs between multipath arrivals. The overall Doppler spectrum of a broadband waveform is the sum of the spectra of all constituent paths and frequencies, and is phenomenologically described by a stretched or compressed exponential. The stretched exponential also fits well to the broadband spectrum of a single propagation path, and narrowband spectra summed over all paths.
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