Active sonar simulation
AssigneesRonald Norwood, Cathy Matthews
InventorsRonald Norwood, Cathy Matthews
Life of this patent
Estimating the term…
Abstract
An exemplary embodiment of the invention relates to a method and system for displaying simulated acoustically realistic active sonar signals. The method includes simulating a realistic sounding active sonar signal that originates from a simulated sonar transmitter. The simulated sonar signal is acted upon and modified by simulated ocean effects and is received by a simulated hydrophone. The sonar signal is acoustically displayed within a simulated ocean acoustic environment that incorporates realistic sounding simulated reverberation.
Claims21
A method in a data processing system for simulating a realistic sounding active sonar signal that originates from a simulated sonar transmitter, the simulated sonar signal being acted upon and modified by simulated ocean effects and then being received by a simulated hydrophone, the sonar signal being acoustically displayed within a simulated ocean acoustic environment that further incorporates realistic sounding simulated reverberation comprising:
- a. creating an ocean physical data file for storing ocean physical data;
- b. creating a noise file for storing the acoustic signatures of the ocean environment;
- c. retrieving random samples from the noise file;
- d. filtering the random samples retrieved from the noise file;
- e. retrieving physical data from the ocean physical data file for calculating reverberation;
- f. calculating reverberation decay using inputs from the physical data file;
- g. modifying the random samples retrieved from the noise file with the calculated reverberation decay;
- h. mixing the modified random samples to create reverberation emulation;
- i. defining distance data, velocity data, aspect pattern data and strength data for contacts of interest;
- j. defining data for sonar platform location and velocity;
- k. selecting a base signal frequency;
- l. selecting a sonar transmission frequency;
- m. initiating a simulated transmission of a sonar transmission signal at the sonar transmission frequency;
- n. calculating a doppler shift for the contacts at the sonar transmission frequency using inputs of the data for the contacts of interest and the data for sonar platform location and velocity;
- o. correcting the base signal frequency for doppler shift;
- p. correcting the base signal for propagation loss;
- q. calculating time of return for the base signal, the time of return being equal to the time of return of the simulated transmission signal at the sonar transmission frequency;
- r. mixing the base signal with the modified reverberation signal;
- and,
- s. outputting the mixed signal.
A data processing system for simulating reverberation in a section of the ocean comprising:
- a. a computer having a means for calculating reverberation quadrature decay;
- b. an output device comprising a speaker for receiving for receiving output from the computer;
- and
- c. a means for producing a simulated reverberation signal having, a noise value from 650 to 950 Hz, an 800 Hz signal, a low frequency reverberation source set of components between 785 to 800 Hz, and a hi frequency reverberation source of components between 800 and 815 Hz.
Dependencies are inferred from the claim text.