Obstacle position and extent measurement by automotive radar
Aspects of the disclosure are directed towards obstacle position and extent measurement. In accordance with one aspect, obstacle detection includes creating one or more interferometric measurements to generate a flow of response position locations using a flow of range/Doppler detections by fitting a parametric expression; and deriving one or more scatterer positions and obstacle position and extent measurements from the flow of response position locations.
1. A method for deriving one or more scatterer position, the method comprising:
receiving a receive radar waveform and generating digitized radar data from the receive radar waveform;
generating one or more interferometric measurements from the digitized radar data to generate a set of response position locations using a set of range/Doppler detections by fitting a parametric expression; and
deriving the one or more scatterer position from the set of response position locations.
2. The method of claim 1 , wherein the receive radar waveform is a scaled replica of a transmit radar waveform with a time delay τ (tau) and a Doppler shift ν (nu) for a scatterer.
3. The method of claim 1 , wherein the receive radar waveform is a scaled replica of a transmit radar waveform.
4. The method of claim 3 , further comprising generating the transmit radar waveform, wherein the transmit radar waveform is a coherent pulsed radar waveform with a plurality of pulses over a coherent time duration.
5. The method of claim 1 , further comprising forming a set of range/cross-range radar images from the digitized radar data.
6. The method of claim 5 , wherein the set of range/cross-range radar images comprises a plurality of resolution cells.
7. The method of claim 6 , wherein the plurality of resolution cells includes a range resolution determined by a signal bandwidth and a cross-range resolution determined by an angular rotation of a radar line of sight.
8. The method of claim 5 , further comprising generating the set of range/Doppler detections from the set of range/cross-range radar images.
9. The method of claim 1 , wherein the parametric expression includes a relative spacing of a ground-bounce and a direct return from a scatterer.
10. The method of claim 1 , further comprising deriving the one or more scatterer position by determining a simultaneous solution for a plurality of scatterers with a least-squares fit using numerical optimization.
11. The method of claim 1 , further comprising deriving the one or more scatterer position by determining an iterative scatterer-by-scatterer solution based on a deconvolution algorithm.
12. The method of claim 11 , wherein the deconvolution algorithm is a CLEAN algorithm.
13. An apparatus for deriving one or more scatterer position, the apparatus comprising:
a radar transceiver configured to receive a receive radar waveform and to generate a digitized radar data from the receive radar waveform;
an interferometric processor configured to generate one or more interferometric measurements from the digitized radar data to generate a set of response position locations using a set of range/Doppler detections by fitting a parametric expression; and
a scatterer processor, coupled to the interferometric processor, configured to derive the one or more scatterer position from the set of response position locations.
14. The apparatus of claim 13 , wherein the interferometric processor and the scatterer processor are two separate components of the apparatus.
15. The apparatus of claim 13 , wherein the receive radar waveform is a scaled replica of a transmit radar waveform with a time delay τ (tau) and a Doppler shift ν (nu) for a scatterer.
16. The apparatus of claim 15 , wherein the transmit radar waveform is a coherent pulsed radar waveform with a plurality of pulses over a coherent time duration.
17. The apparatus of claim 13 , further comprising an image processor, coupled to the radar transceiver, to form a set of range/cross-range radar images from the digitized radar data.
18. The apparatus of claim 17 , further comprising a detection processor, coupled to the image processor, to generate the set of range/Doppler detections from the set of range/cross-range radar images.
19. The apparatus of claim 13 , wherein the scatterer processor derives the one or more scatterer position by determining a simultaneous solution for a plurality of scatterers with a least-squares fit using numerical optimization.
20. The apparatus of claim 13 , wherein the scatterer processor derives the one or more scatterer position by determining an iterative scatterer-by-scatterer solution based on a deconvolution algorithm.
21. The apparatus of claim 13 , wherein the scatterer processor is further configured to derive one or more extent measurements from the set of response position locations.
22. The apparatus of claim 13 , wherein the one or more scatterer position includes at least one obstacle position.
23. The method of claim 1 , further comprising deriving one or more extent measurements from the set of response position locations.
24. The method of claim 1 , wherein the one or more scatterer position includes at least one obstacle position.