Doppler radar flock detection systems and methods
Techniques are disclosed for systems and methods to provide wildlife feeding flock detection using a remote sensing imagery system. A remote sensing imagery system includes a radar assembly mounted to a mobile structure and a coupled logic device. The logic device is configured to receive radar returns corresponding to a detected target, determine a radial velocity spectrum associated with the detected target based, at least in part, on the received radar returns, and determine a probability the detected target includes a feeding flock based, at least in part, on the determined radial velocity spectrum. The logic device may generate radar image data based on the received radar returns, the determined radial velocity spectrum, and/or the probability the detected target includes the feeding flock. Subsequent user input and/or the sensor data may be used to adjust a steering actuator, a propulsion system thrust, and/or other operational systems of the mobile structure.
1. A system comprising:
a radar assembly configured to be mounted to a mobile structure; and
a logic device configured to communicate with the radar assembly, wherein the logic device is configured to:
receive Doppler radar returns corresponding to a detected target from the radar assembly;
determine a radial velocity spectrum associated with the detected target based, at least in part, on the received Doppler radar returns;
determine a probability the detected target comprises a wildlife feeding flock which is a flock in a process of feeding on wildlife, based, at least in part, on the determined radial velocity spectrum and wildlife feeding flock characteristics; and
generate radar image data based, at least in part, on the received radar returns, the determined radial velocity spectrum, and the determined probability the detected target comprises the wildlife feeding flock.
2. The system of claim 1 , wherein the determining the radial velocity spectrum comprises:
determining a centroid range and a centroid azimuth relative to the radar assembly corresponding to a centroid of the detected target; and
determining an azimuth-segmented velocity spectrum corresponding to the centroid azimuth and a range-segmented velocity spectrum corresponding to the centroid range.
3. The system of claim 1 , wherein the determining the radial velocity spectrum comprises:
determining a selection of target azimuths corresponding to a respective selection of Doppler radar beams encompassing at least an azimuth extent of the detected target;
determining a selection of target ranges encompassing at least a range extent of the detected target; and
determining an azimuth-segmented velocity spectrum corresponding to the selection of target azimuths and a range-segmented velocity spectrum corresponding to the selection of target ranges.
4. The system of claim 1 , wherein the determining the radial velocity spectrum comprises:
determining an azimuth-segmented velocity spectrum average and/or a range-segmented velocity spectrum average corresponding to the detected target based, at least in part, on the received Doppler radar returns; and
subtracting the azimuth-segmented velocity spectrum average from a corresponding azimuth-segmented velocity spectrum and/or a range-segmented velocity spectrum average from a corresponding a range-segmented velocity spectrum to compensate for relative motion between the radar assembly and the detected target.
5. The system of claim 1 , wherein the determining the radial velocity spectrum comprises:
identifying background noise in the received Doppler radar returns; and
determining the radial velocity spectrum based on a subset of the received Doppler radar returns that are not identified as background noise and/or that meet or surpass a minimum wildlife feeding flock candidate threshold selected to limit candidate targets.
6. The system of claim 1 , wherein the determining the radial velocity spectrum comprises:
identifying at least one azimuthally overlapping sample of the received Doppler radar returns corresponding to the detected target; and
determining the radial velocity spectrum based on a subset of the received Doppler radar returns that exclude the at least one azimuthally overlapping sample.
7. The system of claim 1 , wherein:
the receiving the Doppler radar returns corresponding to the detected target comprises receiving multiple time-differentiated Doppler radar returns corresponding to time-differentiated scans of an entirety of the detected target; and
the determining the radial velocity spectrum comprises determining multiple time-differentiated radial velocity spectrums associated with the detected target; or
the determining the radial velocity spectrum comprises determining an aggregate time-averaged radial velocity spectrum associated with the detected target.
8. The system of claim 7 , wherein:
the received multiple time-differentiated Doppler radar returns are spatially aligned to an absolute coordinate frame or to a centroid of the detected target determined for each time differentiated scan of the entirety of the detected target.
9. The system of claim 1 , wherein the determining the probability the detected target comprises the wildlife feeding flock comprises:
determining a breadth, differentiation, mean, standard deviation, and/or skewness of an azimuth-segmented velocity spectrum and/or a range-segmented velocity spectrum of the radial velocity spectrum; and
determining the probability based, at least in part, on the determined breadth, differentiation, mean, standard deviation, and/or skewness of the azimuth-segmented velocity spectrum and/or the range-segmented velocity spectrum of the radial velocity spectrum.
10. The system of claim 1 , wherein the determining the probability the detected target comprises the wildlife feeding flock comprises:
determining an azimuthal progression over time of the radial velocity spectrum; and
determining the probability based, at least in part, on the determined azimuthal progression over time of the radial velocity spectrum and/or a characteristic bias change in the radial velocity associated with wildlife feeding flock characteristics.
11. The system of claim 1 , wherein the determining the probability the detected target comprises the wildlife feeding flock comprises:
determining a range and/or azimuthal progression of the radial velocity spectrum; and
determining the probability based, at least in part, on the determined range and/or azimuthal progression over time of the radial velocity spectrum and/or a set of predefined exemplary spectral progression shapes and/or trends associated with wildlife feeding flock characteristics.
12. The system of claim 1 , wherein the determining the probability the detected target comprises the wildlife feeding flock comprises:
determining a classification of the radial velocity spectrum based on a trained convolution neural network applied to a range and/or azimuthal progression over time of the radial velocity spectrum; and
determining the probability based, at least in part, on the determined classification of the radial velocity spectrum.
13. The system of claim 1 , wherein:
the determining the probability is based on a comparison of the determined radial velocity spectrum and the wildlife feeding flock characteristics comprising circulation within the flock indicative of feeding.
14. The system of claim 1 , wherein:
the radar assembly comprises an imaging system coupled to or within the radar assembly and configured to provide image data associated with the radar assembly; and
the logic device is configured to:
receive image data corresponding to the Doppler radar returns from the imaging system; and
generate the radar image data based, at least in part, on the image data corresponding to the Doppler radar returns.
15. The system of claim 14 , wherein:
the generating the radar image data comprises generating panorama image data based, at least in part, on the image data corresponding to the Doppler radar returns, and generating the radar image data comprising a field of view (FoV) indicator overlay corresponding an FoV associated with the generated panorama image data; and
the logic device is configured to generate a display view comprising the radar image data and the generated panorama image data disposed above and/or at least partially spatially mapped to corresponding radar image adjoining the panorama image data.
16. The system of claim 1 , wherein the radar assembly comprises an orientation and position sensor (OPS) coupled to or within the radar assembly and configured to provide orientation and position data associated with the radar assembly, and wherein the logic device is configured to:
receive orientation and/or position data corresponding to the Doppler radar returns from the OPS; and
determine the radial velocity spectrum associated with the detected target based, at least in part, on the Doppler radar returns and the orientation and/or position data corresponding to the radar assembly.
17. The system of claim 16 , wherein the determining the radial velocity spectrum comprises:
determining a Doppler velocity of the target based, at least in part, on the Doppler radar returns;
determining a radial velocity of the radar assembly, corresponding to the determined Doppler velocity of the target, based on the orientation and/or position data corresponding to the radar assembly; and
determining a difference between the Doppler velocity of the target and the radial velocity of the radar assembly.
18. The system of claim 16 , wherein the OPS comprises:
a gyroscope and/or accelerometer coupled to an antenna platform of the radar assembly and disposed at or adjacent to a rotational axis of the radar assembly;
a first global navigation satellite system receiver coupled to the antenna platform and disposed at or adjacent to the rotational axis of the radar assembly; and
a second global navigation satellite system receiver coupled to the antenna platform of the radar assembly and disposed a baseline length from the first global navigation satellite system receiver.
19. The system of claim 1 , further comprising a display configured to communicate with the logic device, wherein the logic device is configured to:
render the radar image data using the display, wherein the rendered radar image data is referenced to an absolute coordinate frame and/or a coordinate frame of the mobile structure;
wherein the system is configured to:
identify and track a non-feeding flock; and
detect conversion of the non-feeding flock to a feeding flock and issue a visual or audible alert.
20. A watercraft comprising the system of claim 19 , where the radar assembly is mounted to the watercraft.