Self-calibrating ultrasonic removal of ectoparasites from fish

1. A computer-implemented method, comprising:

generating, by ultrasonic transducers distributed in a sea lice treatment station, a first set of ultrasonic signals;

detecting, by the ultrasonic transducers, a second set of ultrasonic signals in response to propagation of the first set of ultrasonic signals through water in the sea lice treatment station;

determining propagation parameters of the sea lice treatment station based on the second set of ultrasonic signals that were detected;

obtaining an image of a sea louse on a fish in the sea lice treatment station;

determining, from the image, a location of the sea louse in the sea lice treatment station; and

generating, by the ultrasonic transducers and based on the propagation parameters and the location of the sea louse in the sea lice treatment station, a third set of ultrasonic signals that focuses energy at the sea louse.

2. The method of claim 1 , wherein generating a third set of ultrasonic signals that focuses energy at the sea louse comprises:

determining, from the image, that a portion of the fish is not between a particular ultrasonic transducer and the sea louse; and

based on determining, from the image, that the portion of the fish is not between the particular ultrasonic transducer and the sea louse, generating an ultrasonic signal of the third set of ultrasonic signals with the particular ultrasonic transducer.

3. The method of claim 1 , wherein generating a third set of ultrasonic signals that focuses energy at the sea louse comprises:

determining, from the image, that a portion of the fish is not between a particular ultrasonic transducer and the sea louse; and

based on determining, from the image, that the portion of the fish is not between the particular ultrasonic transducer and the sea louse, determining not to generate an ultrasonic signal with the particular ultrasonic transducer.

4. The method of claim 1 , wherein detecting, by the ultrasonic transducers, a second set of ultrasonic signals in response to propagation of the first set of ultrasonic signals through water in the sea lice treatment station comprises:

detecting, by a first ultrasonic transducer, ultrasonic signals in response to propagation of a first ultrasonic signal that was generated by a second ultrasonic transducer; and

detecting, by the first ultrasonic transducer, ultrasonic signals in response to propagation of a second ultrasonic signal that was generated by a third ultrasonic transducer after the first ultrasonic signal was generated.

5. The method of claim 1 , wherein determining propagation parameters of the sea lice treatment station based on the second set of ultrasonic signals that were detected comprises:

determining at least one of: a pulse width of ultrasonic signals of the second set of ultrasonic signals, a spectral width of ultrasonic signals of the second set of ultrasonic signals, time offsets between detections of the second set of ultrasonic signals and generation of the first set of ultrasonic signals, or reflections of the first set of ultrasonic signals.

6. The method of claim 1 , comprising obtaining sensor data from at least one of a water temperature sensor, a water pressure sensor, or a water salinity sensor,

wherein determining propagation parameters of the sea lice treatment station is based on the sensor data and the second set of ultrasonic signals that were detected.

7. The method of claim 1 , wherein generating, by the ultrasonic transducers and based on the propagation parameters and the location of the sea louse in the sea lice treatment station, a third set of ultrasonic signals that focuses energy at the sea louse comprise:

determining phases of continuous wave ultrasonic signals in the third set of ultrasonic signals.

8. The method of claim 1 , wherein generating, by the ultrasonic transducers and based on the propagation parameters and the location of the sea louse in the sea lice treatment station a third set of ultrasonic signals that focuses energy at the sea louse, comprises:

determining time delays of pulsed ultrasonic signals in the third set of ultrasonic signals.

9. The method of claim 1 , comprising:

determining that ultrasonic signals generated by a particular ultrasonic transducer satisfy self-cleaning criteria; and

based on determining that ultrasonic signals generated by the particular ultrasonic transducer satisfy self-cleaning criteria, generating, by the ultrasonic transducers, a fourth set of ultrasonic signals that focus energy at the particular ultrasonic transducer.

10. A system comprising:

one or more computers and one or more storage devices storing instructions that are operable, when executed by the one or more computers, to cause the one or more computers to perform operations comprising:

generating, by ultrasonic transducers distributed in a sea lice treatment station, a first set of ultrasonic signals;

detecting, by the ultrasonic transducers, a second set of ultrasonic signals in response to propagation of the first set of ultrasonic signals through water in the sea lice treatment station;

determining propagation parameters of the sea lice treatment station based on the second set of ultrasonic signals that were detected;

obtaining an image of a sea louse on a fish in the sea lice treatment station;

determining, from the image, a location of the sea louse in the sea lice treatment station; and

generating, by the ultrasonic transducers and based on the propagation parameters and the location of the sea louse in the sea lice treatment station, a third set of ultrasonic signals that focuses energy at the sea louse.

11. The system of claim 10 , wherein generating a third set of ultrasonic signals that focuses energy at the sea louse comprises:

determining, from the image, that a portion of the fish is not between a particular ultrasonic transducer and the sea louse; and

based on determining, from the image, that the portion of the fish is not between the particular ultrasonic transducer and the sea louse, generating an ultrasonic signal of the third set of ultrasonic signals with the particular ultrasonic transducer.

12. The system of claim 10 , wherein generating a third set of ultrasonic signals that focuses energy at the sea louse comprises:

determining, from the image, that a portion of the fish is not between a particular ultrasonic transducer and the sea louse; and

based on determining, from the image, that the portion of the fish is not between the particular ultrasonic transducer and the sea louse, determining not to generate an ultrasonic signal with the particular ultrasonic transducer.

13. The system of claim 10 , wherein detecting, by the ultrasonic transducers, a second set of ultrasonic signals in response to propagation of the first set of ultrasonic signals through water in the sea lice treatment station comprises:

detecting, by a first ultrasonic transducer, ultrasonic signals in response to propagation of a first ultrasonic signal that was generated by a second ultrasonic transducer; and

detecting, by the first ultrasonic transducer, ultrasonic signals in response to propagation of a second ultrasonic signal that was generated by a third ultrasonic transducer after the first ultrasonic signal was generated.

14. The system of claim 10 , wherein determining propagation parameters of the sea lice treatment station based on the second set of ultrasonic signals that were detected comprises:

determining at least one of: a pulse width of ultrasonic signals of the second set of ultrasonic signals, a spectral width of ultrasonic signals of the second set of ultrasonic signals, time offsets between detections of the second set of ultrasonic signals and generation of the first set of ultrasonic signals, or reflections of the first set of ultrasonic signals.

15. The system of claim 10 , the operations comprising obtaining sensor data from at least one of a water temperature sensor, a water pressure sensor, or a water salinity sensor,

wherein determining propagation parameters of the sea lice treatment station is based on the sensor data and the second set of ultrasonic signals that were detected.

16. The system of claim 10 , wherein generating, by the ultrasonic transducers and based on the propagation parameters and the location of the sea louse in the sea lice treatment station, a third set of ultrasonic signals that focuses energy at the sea louse comprise:

determining phases of continuous wave ultrasonic signals in the third set of ultrasonic signals.

17. The system of claim 10 , wherein generating, by the ultrasonic transducers and based on the propagation parameters and the location of the sea louse in the sea lice treatment station a third set of ultrasonic signals that focuses energy at the sea louse, comprises:

determining time delays of pulsed ultrasonic signals in the third set of ultrasonic signals.

18. A non-transitory computer-readable medium storing software comprising instructions executable by one or more computers which, upon such execution, cause the one or more computers to perform operations comprising:

generating, by ultrasonic transducers distributed in a ectoparasite treatment station, a first set of ultrasonic signals;

detecting, by the ultrasonic transducers, a second set of ultrasonic signals in response to propagation of the first set of ultrasonic signals through water in the ectoparasite treatment station;

determining propagation parameters of the ectoparasite treatment station based on the second set of ultrasonic signals that were detected;

obtaining an image of an ectoparasite on a fish in the ectoparasite treatment station;

determining, from the image, a location of the ectoparasite in the ectoparasite treatment station; and

generating, by the ultrasonic transducers and based on the propagation parameters and the location of the ectoparasite in the ectoparasite treatment station, a third set of ultrasonic signals that focuses energy at the ectoparasite.