Mount for a calibration target for ultrasonic removal of ectoparasites from fish
Methods, systems, and apparatus, including computer programs encoded on computer-storage media, for obtaining initial parameters for ultrasonic transducers around a calibration target. The calibration target can include a fish-shaped structure, sensors placed at different locations of the fish-shaped structure, a processor that receives sensor values from the sensors, and a transmitter that outputs sensor data from the calibration target based on the sensor values. The calibration target can be fixed at a particular position relative to the ultrasonic transducers by a filament coupled to both the calibration target and a support structure. Sensor data can be obtained from the calibration target at the particular position relative to the ultrasonic transducers, and relative locations of the sensors can be determined. Parameters for the ultrasonic transducers around the calibration target can be adjusted based on the sensor data and the respective locations of the sensors.
1. A computer-implemented method, comprising:
obtaining initial parameters for one or more ultrasonic transducers around a calibration target, wherein the calibration target includes:
a fish-shaped structure;
sensors placed at different locations on the fish-shaped structure,
wherein each of the sensors sense energy at a respective location of the fish-shaped structure;
a processor that receives sensor values from the sensors; and
a transmitter that outputs sensor data from the calibration target based on the sensor values,
wherein the calibration target is fixed at a particular position relative to the one or more ultrasonic transducers by a filament coupled to both the calibration target and a support structure;
obtaining the sensor data from the calibration target at the particular position relative to the one or more ultrasonic transducers;
determining the respective locations of the sensors; and
determining adjusted parameters for the one or more ultrasonic transducers around the calibration target based on the sensor data and the respective locations of the sensors.
2. The method of claim 1 wherein: (i) the filament is divided into two or more segments along a long axis, and (ii) each segment of the two or more segments has three or more sides.
3. The method of claim 2 wherein, a cross-section of each segment of the two or more segments comprises a polygon or a closed curve.
4. The method of claim 3 wherein the polygon is a star, a square, a pentagon, or a heptagon.
5. The method of claim 3 wherein, for a first segment of the two or more segments of a first polygon type, and wherein for a second segment of the two or more segments of a second polygon type, and wherein the first segment and the second segment are contiguous, the first polygon type and the second polygon type are different polygon types.
6. The method of claim 2 wherein for each pair of neighboring segments of the two or more segments, a first angle between at least one side of a first segment in the pair of neighboring segments as measured by the long axis differs from a second angle between at least one side of a second segment in the pair as measured by the long axis.
7. The method if claim 2 wherein at least one segment comprises at least one of a square twist, an ellipse twist, a round twist, or a star twist.
8. The method of claim 2 wherein, for at least one segment, the shape of surface features of the one segment increases in spatial frequency as a function of depth from a surface of the segment.
9. The method of claim 1 wherein the filament comprises both a shielding layer and a wire encased by the shielding layer.
10. The method of claim 9 wherein a clear volume of the shielding layer is equal to or exceeds 70%.
11. The method of claim 9 wherein an acoustic impedance of the shield layer is in the range 1.40 MPa s/m 3 to 1.55 MPa s/m 3 .
12. The method of claim 1 wherein the support structure is attached to a sea lice treatment station, a fish tank or to a structure outside the fish tank.