Sensor channel isolation systems and methods
Techniques are disclosed for systems and methods to provide accurate and reliable compact sonar systems for mobile structures. A sonar system includes multiple sensor channels, each comprising a sonar transmitter and a sonar receiver, and a logic device configured to provide control signals and receive sensor signals from the sensor channels. The logic device is configured to provide transmission signals to sonar transducer assemblies, where signal patterns of the transmission signals are differentiated based at least in part on frequency content. Acoustic returns are processed using the signal patterns to reduce inter-channel pickup between the sensor channels. Resulting sonar data and/or imagery may be displayed to a user and/or used to adjust a steering actuator, a propulsion system thrust, and/or other operational systems of the mobile structure.
1. A system comprising:
first and second sensor channels each comprising a sonar transmitter and a sonar receiver; and
a logic device configured to provide one or more control signals and receive one or more sensor signals from the first and second sensor channels, wherein the logic device is adapted to:
provide first and second transmission signals to one or more sonar transducer assemblies, wherein a first signal pattern of the first transmission signal is different from a second signal pattern of the second transmission signal;
receive corresponding first and second acoustic returns from the one or more sonar transducer assemblies; and
process the first and second acoustic returns using the first and second signal patterns to reduce inter-channel pickup between the first and second sensor channels.
2. The system of claim 1 , wherein:
the first and second transmission signals are provided to the one or more transducer assemblies substantially simultaneously;
the processing comprises applying first and second replica correlation filters, based on the first and second signal patterns, to the corresponding first and second acoustic returns; and
the logic device is configured to generate one or more sonar images based, at least in part, on the processed first and second acoustic returns.
3. The system of claim 1 , wherein:
the first signal pattern comprises a low-to-high frequency sweep signal pattern; and
the second signal pattern comprises a high-to-low frequency sweep signal pattern.
4. The system of claim 1 , wherein the first and second signal patterns comprise at least partially overlapping bandwidths.
5. The system of claim 1 , wherein:
the first and second signal patterns comprise substantially non-overlapping bandwidths; and
the non-overlapping bandwidths are disposed substantially at upper and lower bounds of a total available system bandwidth, respectively.
6. The system of claim 1 , wherein:
the first and second signal patterns comprise substantially non-overlapping bandwidths;
the non-overlapping bandwidths are disposed adjacent to each other substantially within a total available system bandwidth; and
one of the non-overlapping bandwidths is disposed substantially at a lower bound of a total available system bandwidth.
7. The system of claim 1 , further comprising a user interface configured to accept user input, wherein the logic device is adapted to:
receive a range selection for the first and/or second sensor channel from the user interface; and
select a bandwidth of the first and/or second signal pattern based on the received range selection.
8. The system of claim 1 , further comprising an assembly bracket configured to couple the one or more sonar transducer assemblies to a mobile structure, wherein:
the one or more sonar transducer assemblies comprise first and second sonar transducer assemblies;
the assembly bracket comprises first and second mating surfaces corresponding to the first and second sonar transducer assemblies; and
the first and second sonar transducer assemblies are adapted to physically couple to the assembly bracket at the first and second mating surfaces, respectively.
9. The system of claim 8 , wherein:
the mobile structure comprises a watercraft; and
the assembly bracket comprises an actuator configured to adjust first and/or second orientations of the respective first and/or second sonar transducer assemblies.
10. The system of claim 1 , further comprising an actuator configured to adjust a transducer orientation corresponding to at least one of the transducer assemblies, wherein the logic device is adapted to:
receive a measured transducer orientation corresponding to the at least one transducer assembly;
determine a transducer orientation adjustment based, at least in part, on a desired transducer orientation and the measured transducer orientation; and
control the actuator to adjust the transducer orientation substantially to the desired transducer orientation.
11. A method comprising:
providing first and second transmission signals to one or more sonar transducer assemblies, wherein a first signal pattern of the first transmission signal is different from a second signal pattern of the second transmission signal;
receiving corresponding first and second acoustic returns from the one or more sonar transducer assemblies; and
processing the first and second acoustic returns using the first and second signal patterns to reduce inter-channel pickup.
12. The method of claim 11 , wherein:
the first and second transmission signals are provided to the one or more transducer assemblies substantially simultaneously;
the processing comprises applying first and second replica correlation filters, based on the first and second signal patterns, to the corresponding first and second acoustic returns; and
the method further comprises generating one or more sonar images based, at least in part, on the processed first and second acoustic returns.
13. The method of claim 11 , wherein:
the first signal pattern comprises a low-to-high frequency sweep signal pattern; and
the second signal pattern comprises a high-to-low frequency sweep signal pattern.
14. The method of claim 11 , wherein the first and second signal patterns comprise at least partially overlapping bandwidths.
15. The method of claim 11 , wherein:
the first and second signal patterns comprise substantially non-overlapping bandwidths; and
the non-overlapping bandwidths are disposed substantially at upper and lower bounds of a total available system bandwidth, respectively.
16. The method of claim 11 , wherein:
the first and second signal patterns comprise substantially non-overlapping bandwidths;
the non-overlapping bandwidths are disposed adjacent to each other substantially within a total available system bandwidth; and
one of the non-overlapping bandwidths is disposed substantially at a lower bound of a total available system bandwidth.
17. The method of claim 11 , further comprising:
receiving a range selection for the first and/or second sensor channel from a user interface; and
selecting a bandwidth of the first and/or second signal pattern based on the received range selection.
18. The method of claim 11 , wherein:
the one or more sonar transducer assemblies comprise first and second sonar transducer assemblies coupled to a mobile structure using an assembly bracket;
the assembly bracket comprises first and second mating surfaces corresponding to the first and second sonar transducer assemblies; and
the first and second sonar transducer assemblies are adapted to physically couple to the assembly bracket at the first and second mating surfaces, respectively.
19. The method of claim 18 , wherein:
the mobile structure comprises a watercraft; and
the assembly bracket comprises an actuator configured to adjust first and/or second orientations of the respective first and/or second sonar transducer assemblies.
20. The method of claim 11 , further comprising:
receiving a measured transducer orientation corresponding to at least one transducer assembly;
determining a transducer orientation adjustment based, at least in part, on a desired transducer orientation and the measured transducer orientation; and
controlling an actuator to adjust the transducer orientation substantially to the desired transducer orientation.