# US 12,181,582 B2 · LIDAR system target detection > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,181,582 B2 - Document ID: US12181582B2 - Status: Granted - Kind: B2 - Application number: 17/140,864 - Filed: 2021-01-04 - Published: 2022-02-24 - Granted: 2024-12-31 - Earliest claimed: 2020-08-18 - Assignees: Aeva, Inc. - Applicants: Aeva, Inc. - Inventors: Kumar Bhargav Viswanatha; Jose Krause Perin; Rajendra Tushar Moorti; Mina Rezk - Web page: https://patentgrep.com/patent/US12181582B2 ## CPC - G01S 17/89: for mapping or imaging - G01S 7/4813: {Housing arrangements} - G01S 7/497: Means for monitoring or calibrating - G01S 17/34: using transmission of continuous, frequency-modulated waves while heterodyning the received signal, or a signal derived therefrom, with a locally-generated signal related to the contemporaneously transmitted signal - G01S 17/42: Simultaneous measurement of distance and other co-ordinates (indirect measurement G01S17/46) - G01S 17/931: of land vehicles - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES ## Abstract A light detection and ranging (LIDAR) system including a processor to receive a return signal from a target based on an optical beam transmitted towards the target and receive a baseband signal in a time domain based on the return signal. The processor of the LIDAR system further to produce a comparison of signal peaks of the baseband signal with an estimate of LIDAR system noise in the frequency domain, and identify targets based on the comparison. ## Claims ### Claim 1 A light detection and ranging (LIDAR) system, comprising: a processor; and a memory to store instructions that, when executed by the processor, cause the LIDAR system to: receive a return signal from a target based on an optical beam transmitted towards the target; receive a baseband signal in a time domain based on the return signal; produce a comparison of signal peaks of the baseband signal with an estimate of LIDAR system noise in the frequency domain; and identify targets based on the comparison. ### Claim 2 (depends on 1) The system of claim 1, wherein the estimate of LIDAR system noise comprises one of an anechoic factory calibration, a low-power boot-up calibration, an anechoic calibration in an occluded field of view (FOV), or a target-absent calibration, and wherein the signal peaks are based on one or more of signal energy across frequency bins of the baseband signal, autocorrelation of the baseband signal across the frequency bins, and cross-correlation between the baseband signal and the system noise estimate across the frequency bins. ### Claim 3 (depends on 2) The system of claim 2, wherein the anechoic factory calibration comprises a measurement of the baseband signal when an entire field of view (FOV) of the optical scanner is occluded by an IR absorber. ### Claim 4 (depends on 2) The system of claim 2, wherein the low-power boot-up calibration comprises a measurement of the baseband signal when the energy of any return signal is below a detection level of the LIDAR system. ### Claim 5 (depends on 1) The system of claim 1, wherein the estimate of LIDAR system noise further comprises a measurement of one or more of noise energy, a mean of the noise energy, a variance of the noise energy, an asymmetry of the noise energy, and a kurtosis of the noise energy. ### Claim 6 (depends on 1) The system of claim 1, wherein the estimate of LIDAR system noise comprises a measurement of the baseband signal when an entire field of view (FOV) of the optical scanner is occluded by an IR absorber. ### Claim 7 (depends on 6) The system of claim 6, wherein the estimate of LIDAR system noise is based on a measurement of the baseband signal when the optical scanner is directed to the entire field of view (FOV) of the optical scanner occluded by the IR absorber. ### Claim 8 (depends on 1) The system of claim 1, wherein the FOV of the optical scanner includes locations without a target reflection, wherein the estimate of LIDAR system noise comprises a target-absent calibration, and wherein the target-absent calibration comprises a measurement of the baseband signal when the optical scanner is directed to a location without a target reflection. ### Claim 9 (depends on 1) The system of claim 1, wherein the processor further causes the LIDAR system to select a highest signal peak independent of the system noise estimate to determine targets. ### Claim 10 (depends on 1) The system of claim 1, wherein the processor further causes the LIDAR system to select a highest signal peak that exceeds a signal-to-noise threshold based on the estimate of LIDAR system noise to identify the targets. ### Claim 11 (depends on 1) The system of claim 1, wherein the processor further causes the LIDAR system to select a signal peak with a highest signal-to-noise ratio to identify the targets. ### Claim 12 A non-transitory computer-readable medium containing instructions that, when executed by a processor in a light detection and ranging (LIDAR) system, causes the LIDAR system to: receive a return signal from a target based on an optical beam transmitted towards the target; receive a baseband signal in a time domain based on the return signal; produce a comparison of signal peaks of the baseband signal with an estimate of LIDAR system noise in the frequency domain; and identify targets based on the comparison. ### Claim 13 (depends on 12) The non-transitory computer-readable medium of claim 12, wherein the estimate of LIDAR system noise comprises one of an anechoic factory calibration, a low-power boot-up calibration, an anechoic calibration in an occluded field of view (FOV), or a target-absent calibration, and wherein the signal peaks are based on one or more of signal energy across frequency bins of the baseband signal, autocorrelation of the baseband signal across the frequency bins, and cross-correlation between the baseband signal and the system noise estimate across the frequency bins. ### Claim 14 (depends on 12) The non-transitory computer-readable medium of claim 12, wherein the estimate of LIDAR system noise further comprises a measurement of one or more of noise energy, a mean of the noise energy, a variance of the noise energy, an asymmetry of the noise energy, and a kurtosis of the noise energy. ### Claim 15 (depends on 12) The non-transitory computer-readable medium of claim 12, wherein the processor further causes the LIDAR system to select a highest signal peak independent of the system noise estimate to determine targets. ### Claim 16 (depends on 12) The non-transitory computer-readable medium of claim 12, wherein the processor further causes the LIDAR system to select a highest signal peak that exceeds a signal-to-noise threshold based on the estimate of LIDAR system noise to identify the targets. ### Claim 17 (depends on 12) The non-transitory computer-readable medium of claim 12, wherein the processor further causes the LIDAR system to select a signal peak with a highest signal-to-noise ratio to identify the targets. ### Claim 18 (depends on 12) The non-transitory computer-readable medium of claim 12, wherein the estimate of LIDAR system noise comprises a measurement of the baseband signal when an entire field of view (FOV) of the optical scanner is occluded by an IR absorber. ### Claim 19 (depends on 18) The non-transitory computer-readable medium of claim 18, wherein the estimate of LIDAR system noise is based on a measurement of the baseband signal when the optical scanner is directed to the entire field of view (FOV) of the optical scanner occluded by the IR absorber. ### Claim 20 (depends on 12) The non-transitory computer-readable medium of claim 12, wherein the FOV of the optical scanner includes locations without a target reflection, wherein the estimate of LIDAR system noise comprises a target-absent calibration, and wherein the target-absent calibration comprises a measurement of the baseband signal when the optical scanner is directed to a location without a target reflection.