Correlation sonar system
AssigneeRowe, Deines Instruments Incorporated
InventorsSteven E. Bradley, Francis D. Rowe
Life of this patent
Estimating the term…
Abstract
In a correlation device, a system and method for measuring velocities using a single coded pulse generator. The correlation device may also include maximum likelihood estimation techniques for processing the echo signals received from a plurality of transducers. The presently preferred embodiment of the device is as a current profiler having a bottom tracking capability for providing vessel velocity.
Claims28
A correlation sonar system, comprising:
- a transmitting transducer for emitting acoustic energy onto a reflecting surface;
- pulse generation means for generating a single pulse of electrical energy to the transmitting transducer;
- a plurality of receiving transducers for receiving a pulse echo from the reflecting surface;
- a plurality of demodulators, each demodulator connected to one of the receiving transducers and generating a set of values;
- means for cross-correlating the values for each receiving transducer at a predetermined time delay less than the pulse width;
- and
- maximum likelihood means for estimating velocity using correlated values.
A correlation system, comprising:
- means for generating a pulse into a liquid having reflective surfaces;
- a plurality of transducers for receiving the echo signal created by the pulse contacting the reflective surfaces;
- correlation means for forming a first set of correlations of the echo signal received at time lag 0 and a second set of correlations at time lag .tau.;
- and
- maximum likelihood means for maximizing the probability of a set of preselected parameters, including at least one component of velocity, having sets of correlations indicative of a parameter state.
In a correlation system for measuring velocities having a transmitting transducer and a plurality of receiving transducers, a method comprising the steps of:
- transmitting a pulse of energy in the direction of a reflective surface;
- receiving the pulse energy echo at each receiving transducer as a set of received values;
- calculating correlation values from the received values;
- providing initial estimates of a set of unknown parameters;
- and
- maximum likelihood processing the correlation values and initial estimates of parameters to maximize the probability of the system having a specific set of parameters given the correlation values.
Dependencies are inferred from the claim text.