Systems and methods for improving detection of a return signal in a light ranging and detection system
Described herein are systems and methods for improving detection of a return signal in a light ranging and detection system. The system comprises a transmitter and a receiver. A first sequence of pulses may be encoded with an anti-spoof signature and transmitted in a laser beam. A return signal, comprising a second sequence of pulses, may be received by the receiver and the anti-spoof signature extracted from the second sequence of pulses. If based on the extraction, the first and second sequences of pulses match, the receiver outputs return signal data. If based on the extraction, the first and second sequence of pulses do not match, the return signal is disregarded. The system may dynamically change the anti-spoofing signature for subsequent sequences of pulses. Additionally, the first sequence of pulses may be randomized relative to a prior sequence of pulses.
1. A system comprising:
a signature extractor operable for selecting a transmission anti-spoofing signature to be embedded in a transmitted laser beam;
an anti-spoofing encoder operable to embed the transmission anti-spoofing signature in the transmitted laser beam;
a controller;
a photo detector operable to receive a reflection of the transmitted laser beam off an object and generate a return signal; and
a data acquisition component,
wherein, to validate the return signal, the signature extractor extracts a return anti- spoofing signature from the return signal and determines whether one or more characteristics of a received pulse sequence of the return anti-spoofing signature match, within respective thresholds, one or more characteristics of a transmitted sequence of pulses of the transmission anti-spoofing signature, the one or more characteristics including one or more of variations in a number of pulses, variations in distances between pulses, variations of pulse amplitude ratios, variations of pulse widths, or a combination thereof, and
wherein the data acquisition component determines, based on at least one pulse of the received pulse sequence of the return anti-spoofing signature of the validated return signal, a distance between the photo detector and the object, such that the at least one pulse of the received pulse sequence of the return anti-spoofing signature is used to validate the return signal and to determine the distance between the photo detector and the object.
2. The system of claim 1 , wherein if the one or more characteristics of the return signal match the one or more characteristics of the transmitted laser beam, the signature extractor validates the return signal and outputs data of the return signal.
3. The system of claim 1 , wherein if the one or more characteristics of the return signal do not match the one or more characteristics of the transmitted laser beam, the signature extractor outputs an alert.
4. The system of claim 1 , wherein for a next sequence of pulses to be transmitted, the signature extractor dynamically changes the transmission anti-spoofing signature.
5. The system of claim 1 , further comprising a random encoder operable to randomize the one or more characteristics of the sequence of pulses to be transmitted relative to a prior sequence of transmitted pulses.
6. The system of claim 1 , wherein data indicating environmental conditions received by the controller define the one or more characteristics for the sequence of pulses of the transmitted laser beam.
7. The system of claim 6 , wherein the transmission anti-spoofing signature is dynamically changed based on the environmental conditions.
8. The system of claim 6 , wherein the one or more characteristics of the sequence of pulses of the transmitted laser beam are randomized based on the environmental conditions.
9. The system of claim 6 , wherein the environmental conditions comprise weather, congestion, or test/calibration/factory conditions.
10. The system of claim 1 , wherein the anti-spoofing encoder is operable to generate the transmission anti-spoofing signature based on pulses having the variations in a number of pulses in two or more sequences of pulses, the variations in distances between pulses, the variations of pulse amplitude ratios, or the variations of pulse widths.
11. A method comprising:
selecting a transmission anti-spoofing signature;
encoding the transmission anti-spoofing signature in a first sequence of pulses;
firing a laser beam comprising the first sequence of pulses;
receiving, with a photo detector, a reflection of the laser beam off an object and generating a return signal;
determining whether the return signal is validated by extracting a return anti-spoofing signature from the return signal and determining whether one or more characteristics of a second sequence of pulses of the return anti-spoofing signature match, within respective thresholds, one or more characteristics of the first sequence of pulses, wherein the one or more characteristics include one or more variations in a number of pulses, variations in distances between pulses, variations of pulse amplitude ratios, variations of pulse widths, or a combination thereof; and
determining, based on at least one pulse of the second sequence of pulses of the return anti-spoofing signature of the validated return signal, a distance between the photo detector and the object, such that the at least one pulse of the second sequence of pulses of the return anti- spoofing signature is used to validate the return signal and to determine the distance between the photo detector and the object.
12. The method of claim 11 , further comprising dynamically changing the transmission anti-spoofing signature for a next sequence of pulses to be transmitted.
13. The method of claim 11 , further comprising randomizing characteristics of a next sequence of pulses to be transmitted.
14. The method of claim 11 , further comprising,
if the second sequence of pulses matches the first sequence of pulses, generating a data output of the return signal.
15. The method of claim 11 , further comprising,
if the second sequence of pulses does not match the first sequence of pulses, generating an alert.
16. The method of claim 11 , further comprising, adjusting the first sequence of pulses based on environmental conditions, wherein the environmental conditions comprise weather, congestion, test/calibration/factory conditions.
17. The method of claim 11 , wherein anti-spoofing signature detection is implemented with variable thresholds.
18. A non-transitory computer readable storage medium having computer program code stored thereon, the computer program code, when executed by one or more processors implemented on a light detection and ranging system, causes the light detection and ranging system to perform a method comprising:
selecting a second anti-spoofing signature for a second sequence of pulses that is different than a first anti-spoofing signature utilized in a previously transmitted first sequence of pulses;
encoding the second anti-spoofing signature in the second sequence of pulses;
randomizing the second sequence of pulses;
firing a laser beam comprising the second sequence of pulses;
receiving, with a photo detector, a reflection of the laser beam off an object and generating a return signal;
determining whether the return signal is validated by extracting a return anti-spoofing signature from the return signal and determining whether one or more characteristics of a third sequence of pulses of the return anti-spoofing signature match, within respective thresholds, one or more characteristics of the second sequence of pulses, wherein the one or more characteristics include one or more variations in a number of pulses, variations in distances between pulses, variations of pulse amplitude ratios, variations of pulse widths, or a combination thereof; and
determining, based on at least one pulse of the third pulse sequence of the return anti-spoofing signature of the validated return signal, a distance between the photo detector and the object, such that the at least one pulse of the third pulse sequence of the return anti-spoofing signature is used to validate the return signal and to determine the distance between the photo detector and the object.
19. The storage medium of claim 18 , wherein the method further comprises:
if the third sequence of pulses matches the second sequence of pulses, generating a data output based on the return signal.
20. The storage medium of claim 18 , wherein the method further comprises:
if the third sequence of pulses does not match the second sequence of pulses, generating an alert.