Abstract: An apparatus is provided for using a square wave digital chirp signal for optical chirp range detection. A laser source emits an optical signal and a RF waveform generator generates an input digital chirp signal based on the square wave digital chirp signal. A frequency of the optical signal is modulated based on the input digital chirp signal. A splitter divides the optical signal into a transmit optical signal and a reference optical signal. A detector combines the reference optical signal and a return optical signal from an object. The detector generates an electrical output signal based on the combined reference optical signal and the return optical signal. A processor determines a range to the object based on a characteristic of a Fourier transform the electrical output signal. A method is also provided for using the square wave digital chirp signal for optical chirp range detection.

Abstract: An apparatus is provided for using a square wave digital chirp signal for optical chirp range detection. A laser source emits an optical signal and a RF waveform generator generates an input digital chirp signal based on the square wave digital chirp signal. A frequency of the optical signal is modulated based on the input digital chirp signal. A splitter divides the optical signal into a transmit optical signal and a reference optical signal. A detector combines the reference optical signal and a return optical signal from an object. The detector generates an electrical output signal based on the combined reference optical signal and the return optical signal. A processor determines a range to the object based on a characteristic of a Fourier transform the electrical output signal. A method is also provided for using the square wave digital chirp signal for optical chirp range detection.

Abstract: Laser 3D imaging techniques include splitting a laser temporally-modulated waveform of bandwidth B and duration D from a laser source into a reference beam and a target beam and directing the target beam onto a target. First data is collected, which indicates amplitude and phase of light relative to the reference beam received at each of a plurality of different times during a duration D at each optical detector of an array of one or more optical detectors perpendicular to the target beam. Steps are repeated for multiple sampling conditions, and the first data for the multiple sampling conditions are synthesized to form one or more synthesized sets. A 3D Fourier transform of each synthesized set forms a digital model of the target for each synthesized set with a down-range resolution based on the bandwidth B.

Abstract: Techniques for automatic adaptive scanning with a laser scanner include obtaining range measurements at a coarse angular resolution and forming a horizontally sorted range gate subset and a characteristic range. A fine angular resolution is determined automatically based on the characteristic range and a target spatial resolution. If the fine angular resolution is finer than the coarse angular resolution, then a minimum and maximum vertical angle is automatically determined in each horizontal slice extending a bin size from any previous horizontal slice. A set of adaptive minimum and maximum vertical angles is determined automatically by dilating and interpolating the minimum and maximum vertical angles of all the slices to the second horizontal angular resolution. A horizontal start angle, and the set of adaptive minimum and maximum vertical angles are sent to cause the ranging system to obtain measurements at the second angular resolution.

Abstract: Techniques for adaptive scanning with a laser scanner include obtaining range measurements at a coarse angular resolution and determining a range gate subset and a characteristic range. A fine angular resolution is based on the characteristic range and a target spatial resolution. If the fine angular resolution is finer than the coarse angular resolution, then a minimum vertical angle and maximum vertical angle is determined for a horizontal slice of the subset of angular width based on the first angular resolution. The scanning laser ranging system is then operated to obtain second range measurements at the second angular resolution in the slice between the minimum vertical angle and the maximum vertical angle. In some embodiments, the scanning is repeated for each horizontal slice in the range gate subset using a minimum vertical angle and maximum vertical angle for that slice.

Abstract: A method for classifying an object in a point cloud includes computing first and second classification statistics for one or more points in the point cloud. Closest matches are determined between the first and second classification statistics and a respective one of a set of first and second classification statistics corresponding to a set of N classes of a respective first and second classifier, to estimate the object is in a respective first and second class. If the first class does not correspond to the second class, a closest fit is performed between the point cloud and model point clouds for only the first and second classes of a third classifier. The object is assigned to the first or second class, based on the closest fit within near real time of receiving the 3D point cloud. A device is operated based on the assigned object class.

Abstract: Doppler correction of phase-encoded LIDAR includes a code indicating a sequence of phases for a phase-encoded signal, and determining a first Fourier transform of the signal. A laser optical signal is used as a reference and modulated based on the code to produce a transmitted phase-encoded optical signal. A returned optical signal is received in response. The returned optical signal is mixed with the reference. The mixed optical signals are detected to produce an electrical signal. A cross spectrum is determined between in-phase and quadrature components of the electrical signal. A Doppler shift is based on a peak in the cross spectrum. A device is operated based on the Doppler shift. Sometimes a second Fourier transform of the electrical signal and the Doppler frequency shift produce a corrected Fourier transform and then a cross correlation. A range is determined based on a peak in the cross correlation.

Abstract: Doppler correction of broadband LIDAR includes mixing, during a first time interval, a returned optical signal with an in-phase version of the transmitted signal to produce a first mixed optical signal that is detected during the first time interval to produce a first electrical signal. During a non-overlapping second time interval the returned optical signal is mixed with a quadrature version of the transmitted signal to produce a second mixed optical signal that is detected during the second time interval to produce a second electrical signal. A complex digital signal uses one of the digitized electrical signals as a real part and a different one as the imaginary part. A signed Doppler frequency shift of the returned optical signal is determined based, at least in part, on a Fourier transform of the complex digital signal. A device is operated based on the Doppler frequency shift.

Abstract: Techniques for Doppler correction of chirped optical range detection include obtaining a first set of ranges based on corresponding frequency differences between a return optical signal and a first chirped transmitted optical signal with an up chirp that increases frequency with time. A second set of ranges is obtained based on corresponding frequency differences between a return optical signal and a second chirped transmitted optical signal with a down chirp. A matrix of values for a cost function is determined, one value for each pair of ranges that includes one in the first set and one in the second set. A matched pair of one range in the first set and a corresponding one range in the second set is determined based on the matrix. A Doppler effect on range is determined based on combining the matched pair of ranges. A device is operated based on the Doppler effect.

Abstract: Doppler correction of phase-encoded LIDAR includes a code indicating a sequence of phases for a phase-encoded signal, and determining a first Fourier transform of the signal. A laser optical signal is used as a reference and modulated based on the code to produce a transmitted phase-encoded optical signal. A returned optical signal is received in response. The returned optical signal is mixed with the reference. The mixed optical signals are detected to produce an electrical signal. A cross spectrum is determined between in-phase and quadrature components of the electrical signal. A Doppler shift is based on a peak in the cross spectrum. A device is operated based on the Doppler shift. Sometimes a second Fourier transform of the electrical signal and the Doppler frequency shift produce a corrected Fourier transform and then a cross correlation. A range is determined based on a peak in the cross correlation.

Abstract: Doppler correction of broadband LIDAR includes mixing, during a first time interval, a returned optical signal with an in-phase version of the transmitted signal to produce a first mixed optical signal that is detected during the first time interval to produce a first electrical signal. During a non-overlapping second time interval the returned optical signal is mixed with a quadrature version of the transmitted signal to produce a second mixed optical signal that is detected during the second time interval to produce a second electrical signal. A complex digital signal uses one of the digitized electrical signals as a real part and a different one as the imaginary part. A signed Doppler frequency shift of the returned optical signal is determined based, at least in part, on a Fourier transform of the complex digital signal. A device is operated based on the Doppler frequency shift.

Abstract: Laser 3D imaging techniques include splitting a laser temporally-modulated waveform of bandwidth B and duration D from a laser source into a reference beam and a target beam and directing the target beam onto a target. First data is collected, which indicates amplitude and phase of light relative to the reference beam received at each of a plurality of different times during a duration D at each optical detector of an array of one or more optical detectors perpendicular to the target beam. Steps are repeated for multiple sampling conditions, and the first data for the multiple sampling conditions are synthesized to form one or more synthesized sets. A 3D Fourier transform of each synthesized set forms a digital model of the target for each synthesized set with a down-range resolution based on the bandwidth B.

Abstract: An apparatus is provided for using a square wave digital chirp signal for optical chirp range detection. A laser source emits an optical signal and a RF waveform generator generates an input digital chirp signal based on the square wave digital chirp signal. A frequency of the optical signal is modulated based on the input digital chirp signal. A splitter divides the optical signal into a transmit optical signal and a reference optical signal. A detector combines the reference optical signal and a return optical signal from an object. The detector generates an electrical output signal based on the combined reference optical signal and the return optical signal. A processor determines a range to the object based on a characteristic of a Fourier transform the electrical output signal. A method is also provided for using the square wave digital chirp signal for optical chirp range detection.

Abstract: Doppler correction of broadband LIDAR includes mixing, during a first time interval, a returned optical signal with an in-phase version of the transmitted signal to produce a first mixed optical signal that is detected during the first time interval to produce a first electrical signal. During a non-overlapping second time interval the returned optical signal is mixed with a quadrature version of the transmitted signal to produce a second mixed optical signal that is detected during the second time interval to produce a second electrical signal. A complex digital signal uses one of the digitized electrical signals as a real part and a different one as the imaginary part. A signed Doppler frequency shift of the returned optical signal is determined based, at least in part, on a Fourier transform of the complex digital signal. A device is operated based on the Doppler frequency shift.

Abstract: Doppler correction of phase-encoded LIDAR includes a code indicating a sequence of phases for a phase-encoded signal, and determining a first Fourier transform of the signal. A laser optical signal is used as a reference and modulated based on the code to produce a transmitted phase-encoded optical signal. A returned optical signal is received in response. The returned optical signal is mixed with the reference. The mixed optical signals are detected to produce an electrical signal. A cross spectrum is determined between in-phase and quadrature components of the electrical signal. A Doppler shift is based on a peak in the cross spectrum. A device is operated based on the Doppler shift. Sometimes a second Fourier transform of the electrical signal and the Doppler frequency shift produce a corrected Fourier transform and then a cross correlation. A range is determined based on a peak in the cross correlation.

Abstract: Laser 3D imaging techniques include splitting a laser temporally-modulated waveform of bandwidth B and duration D from a laser source into a reference beam and a target beam and directing the target beam onto a target. First data is collected, which indicates amplitude and phase of light relative to the reference beam received at each of a plurality of different times during a duration D at each optical detector of an array of one or more optical detectors perpendicular to the target beam. Steps are repeated for multiple sampling conditions, and the first data for the multiple sampling conditions are synthesized to form one or more synthesized sets. A 3D Fourier transform of each synthesized set forms a digital model of the target for each synthesized set with a down-range resolution based on the bandwidth B.

Abstract: Laser 3D imaging techniques include splitting a laser temporally-modulated waveform of bandwidth B and duration D from a laser source into a reference beam and a target beam and directing the target beam onto a target. First data is collected, which indicates amplitude and phase of light relative to the reference beam received at each of a plurality of different times during a duration D at each optical detector of an array of one or more optical detectors perpendicular to the target beam. Steps are repeated for multiple sampling conditions, and the first data for the multiple sampling conditions are synthesized to form one or more synthesized sets. A 3D Fourier transform of each synthesized set forms a digital model of the target for each synthesized set with a down-range resolution based on the bandwidth B.