Patent classifications
G01S17/26
Ladar system and method with cross-receiver
A ladar system and related method are disclosed where the system includes a ladar transmitter and a ladar receiver. The ladar transmitter transmits ladar pulses into a field of view, and the ladar receiver receives ladar pulse returns from objects in the field of view. The ladar receiver comprises a cross-receiver, the cross-receiver comprising a first 1D array of photodetector cells and a second 1D array of photodetector cells that are oriented differently relative to each other.
LiDAR apparatus using interrupted continuous wave light
A light detection and ranging (LiDAR) apparatus capable of extracting speed information and distance information of objects in front thereof is provided. The LiDAR apparatus includes: a continuous wave light source configured to generate continuous wave light; a beam steering device configured to emit the continuous wave light to an object for a first time and stop emitting the continuous wave light to the object for a second time; a receiver configured to receive the continuous wave light that is reflected from the object to form a reception signal; and a signal processor configured to obtain distance information and speed information about the object based on the reception signal.
LiDAR apparatus using interrupted continuous wave light
A light detection and ranging (LiDAR) apparatus capable of extracting speed information and distance information of objects in front thereof is provided. The LiDAR apparatus includes: a continuous wave light source configured to generate continuous wave light; a beam steering device configured to emit the continuous wave light to an object for a first time and stop emitting the continuous wave light to the object for a second time; a receiver configured to receive the continuous wave light that is reflected from the object to form a reception signal; and a signal processor configured to obtain distance information and speed information about the object based on the reception signal.
Systems and methods for chirp linearization using a partial reflector as a reference reflector
Disclosed herein are systems and methods for linearizing frequency chirp in a frequency-modulated continuous wave (FMCW) coherent LiDAR system. Exemplary methods can include generating a continuous wave laser signal having a frequency characteristic, in which the frequency characteristic can include a frequency chirp over a frequency band in at least one period; and receiving a signal based on the generated laser signal. The methods can further include mixing the received signal with a local oscillator signal, the local oscillator signal having the frequency characteristic; determining at least one beat frequency based on the mixed signal; sampling the mixed signal at a rate equal to at least two times the beat frequency; determining a correction signal based on the sampled signal; and applying the correction signal to the laser signal.
Systems and methods for chirp linearization using a partial reflector as a reference reflector
Disclosed herein are systems and methods for linearizing frequency chirp in a frequency-modulated continuous wave (FMCW) coherent LiDAR system. Exemplary methods can include generating a continuous wave laser signal having a frequency characteristic, in which the frequency characteristic can include a frequency chirp over a frequency band in at least one period; and receiving a signal based on the generated laser signal. The methods can further include mixing the received signal with a local oscillator signal, the local oscillator signal having the frequency characteristic; determining at least one beat frequency based on the mixed signal; sampling the mixed signal at a rate equal to at least two times the beat frequency; determining a correction signal based on the sampled signal; and applying the correction signal to the laser signal.
Switchable Multi-Lens Lidar Receiver
A lidar system comprises a first lens, a second lens, and a switch. The first lens has a first field of view that receives incident light from the first field of view. The second lens has a second field of view that receives incident light from the second field of view, wherein the second field of view is encompassed by and narrower than the first field of view. The switch controls which of the first and second lenses are used for detecting returns from laser pulse shots based on where the laser pulse shots are targeted in a field of view that encompasses the first and second fields of view. The switch may comprise an optical switch or an electronic switch.
Switchable Multi-Lens Lidar Receiver
A lidar system comprises a first lens, a second lens, and a switch. The first lens has a first field of view that receives incident light from the first field of view. The second lens has a second field of view that receives incident light from the second field of view, wherein the second field of view is encompassed by and narrower than the first field of view. The switch controls which of the first and second lenses are used for detecting returns from laser pulse shots based on where the laser pulse shots are targeted in a field of view that encompasses the first and second fields of view. The switch may comprise an optical switch or an electronic switch.
Frequency modulated continuous wave LIDAR with locked dual lasers
A frequency-modulated continuous wave (FMCW) LIDAR can be configured to reduce re-reflection and cross-coupling in the FMCW LIDAR. A first laser can be configured to generate a ranging signal, and a second laser can be configured to generate a local oscillator signal. A feedback control can be configured to maintain an offset between the ranging signal and the local oscillator signal. The offset can be a non-zero value. A transmit portion configured to emit a reference laser signal based on the ranging signal into an environment. A receiver portion can be configured to receive a return laser signal from the environment. The return laser signal can be a reflected version of the reference laser signal. A receiver photodetector can be configured to combine the return laser signal and the local oscillator signal.
Frequency modulated continuous wave LIDAR with locked dual lasers
A frequency-modulated continuous wave (FMCW) LIDAR can be configured to reduce re-reflection and cross-coupling in the FMCW LIDAR. A first laser can be configured to generate a ranging signal, and a second laser can be configured to generate a local oscillator signal. A feedback control can be configured to maintain an offset between the ranging signal and the local oscillator signal. The offset can be a non-zero value. A transmit portion configured to emit a reference laser signal based on the ranging signal into an environment. A receiver portion can be configured to receive a return laser signal from the environment. The return laser signal can be a reflected version of the reference laser signal. A receiver photodetector can be configured to combine the return laser signal and the local oscillator signal.
LIDAR system to adjust doppler effects
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.