The concept, design, and ocean testing of a low-power acoustic modem are presented. The telemetry system uses a novel chirp frequency sweep and has other features to allow operation in the presence of multipath interference. The chirp system uses frequency-shift keyed data modulation and performs a carrier sweep starting at 9 or 31 kHz, depending on the model, to obtain the benefits of frequency diversity without requiring a frequency synthesizer, multiple filters, or fast Fourier transform analyzer. Intended for retrofit to existing instruments, the system is designed for use in the deep ocean and the continental shelf over distances to 6 km. Ocean tests were performed in about 4000 m of water using the low-frequency version. Additional shallow-water tests are planned, including a typical harbor.
Deep-ocean tests of an acoustic modem insensitive to multipath distortion
Tests im tiefen Ozean mit einem akustischen Modem, der unempfindlich gegen Mehrpfadverzerrung ist
1988
8 Seiten, 22 Quellen
Aufsatz (Konferenz)
Englisch
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