Sonar reverberation simulation
AssigneeThe United States of America as represented by the Secretary of the Navy
InventorArthur B. Clapsaddle
Life of this patent
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Abstract
Simulation of sonar reverberation signals is accomplished from square pul the timing and duration of which are computer determined by known principles by processing the pulses through novel shaper means including diode controlled charging and discharging of a capacitor through different selected resistances to provide appropriate ascent and descent curves to the pulses. The shaped pulses are then used to pulse modulate a doppler-shifted carrier signal which is generated by a voltage controlled oscillator responsive to control signals which are functions of ship's speed, transmission angle and the like. The resulting pulse modulated doppler-shifted carrier is then attentuated to provide the desired simulated reverberation signal components.
Claims7
A sonar reverberation signal generator for generating reverberation signal components comprised of a doppler-shifted carrier having an envelope characterized by predetermined ascent and descent curves, said generator comprising:
- a source of transmit pulses;
- logic means responsive to said transmit pulses and operative to provide timing signals;
- pulse generator means responsive to said timing signals to provide squared voltage pulses of predetermined duration;
- shaper means connected to receive said squared voltage pulses and to shape said pulses to provide shaped pulses having said predetermined ascent and descent curves;
- carrier generator means for generating a simulated doppler shifted carrier signal;
- modulator means connected to receive said carrier signal and said shaped pulses and operative to modulate the former with the latter to provide pulse modulated carrier signals having an envelope characterized by said ascent and descent curves;
- and
- attenuator means connected to receive said pulse modulated carrier signals and operative to reduce the amplitude thereof to provide said simulated reverberation signal components.
Dependencies are inferred from the claim text.