Abstract: Various measurement systems and methods are disclosed to enable characterizing the optical characteristics of light beams emitted by a light detection and range finding (LIDAR) system or sensor and evaluating the range finding function of user selected lidar channels while the lidar operates under a real operational condition and is exposed to a range of user defined environmental conditions.

Abstract: Provided are methods for camera-assisted LiDAR data verification. A vehicle (such as an autonomous vehicle) has multiple sensors mounted at various locations on the vehicle. Data from these sensors can be used for object detection. In object detection, sensor data is analyzed to annotate portions of the sensor data with confidence scores that indicate the presence of a particular object class instance within a respective portion of the data captured by a sensor. Systems and computer program products are also provided.

Abstract: Various methods and systems are disclosed to reduce the false alarm in a lidars having a lidar window surrounding the lidar system, by increasing the propagation loss for a portion of incident light that propagates within the thickness of the lidar window and may be guided toward the detection system of the lidar via an indirect path. Alternatively, or in addition, the shape of the lidar window may be tailored to direct the portion of incident light that propagates within the thickness of the lidar window away from the lidar detection system.

Abstract: Described are techniques for processing a laser signal to illuminate an external scene that is sectored in pixels by a laser device. This includes frequency modulating a laser signal in up and down-chirps, illuminating the external scene, receiving a reflected laser signal, measuring an up-beat signal, measuring a down-beat signal, simultaneously illuminating the external scene with the up-chirp and with the down-chirp for at least one pixel, and amplitude modulating the modulated laser signal of at least two adjacent pixels, so that the calculating unit can distinguish the reflected laser signals of two adjacent pixels. This way, in order to allow for fast scanning of a single frame, up- and down-chirps are sent out simultaneously to scan a complete pixel row or line within one ramp without any waiting time and without any chirp reset on each pixel.

Abstract: Provided are methods, systems, and computer program products for a LiDAR with an increased dynamic range. The method includes filtering output pulses of an SiPM device to a substantially symmetric pulse shape and capturing timing information and intensity information of the filtered output pulses for at least one predetermined intensity level. The method includes monitoring saturation of the SiPM device, wherein a width of a saturation plateau of a respective output pulse is determined in response to saturation of the SiPM device. The method also includes extrapolating additional timing information and additional intensity information of the respective output pulse using the captured timing information, the captured intensity information, and the determined width of the saturation plateau.

Abstract: This document describes a time-of-flight lidar system configured to process pulse trains instead of individual pulses, for improved range resolution and pixel throughput. Each pulse in the pulse train is output at a respective duration and intensity, which may vary to provoke a return with a high-intensity and low signal ambiguity, prevent thermal build-up, or promote safe ocular operation. An expected intensity of the return as a function of time can be determined. By sampling reflections at the expected times and intensities, the lidar system quickly identifies a corresponding lidar return, even despite lidar noise. A return time of the return can indicate a distance or speed associated with an object pixel in a field-of-view. Processing pulse trains instead of individual pulses allows pixels to be scanned faster than using long durations or frame times, which also promotes ocular safety. Increased throughput is realized using low-energy lasers and inexpensive hardware, which minimize thermal footprint.

Abstract: This document describes techniques and systems to vary waveforms across frames in lidar systems. The described lidar system transmits signals with different waveforms for the same pixel of consecutive frames to avoid a return signal overlapping with a noise spike or a frequency component of another return signal. The different waveforms can be formed using different frequency modulations, different amplitude modulations, or a combination thereof for the same pixel of consecutive frames. The lidar system can change the waveform of the transmit signal for the same pixel of a subsequent frame automatically or in response to determining that a signal-to-noise ratio of the return signal of an initial frame is below a threshold value. In this way, the lidar system can increase the signal-to-noise ratios in return signals. These improvements allow the lidar system to increase its accuracy in determining the characteristics of objects that reflected the return signals.

Abstract: Various methods and systems are disclosed to improve detection probability of time of flight lidar systems by generating real-time background signals for individual pixels of a sensor of the lidar detection system and use the background signals to dynamically control the detection system of the lidar. The background signals, that indicate the amount of background light received by different pixels, are used for controlling the detection system by adjusting at least one of the optical system, the sensor, and the readout system of the detection system in order to reduce the impact of the back ground light on the detection and range finding functionality of the lidar.

Abstract: Various methods and systems are disclosed to improve the reliability and accuracy of a time of flight lidar systems by generating real-time background signals for individual pixels of a sensor of the lidar detection system and use the background signals to generate confidence signals. The confidence signal indicates validity of a return signal or a probability that the return signal is not associated with interference with another lidar or light source. The confidence signals may be used by the lidar system to reduce the false alarm rate of the lidar.

Abstract: This document describes techniques and systems to alternate power-level scanning for ToF lidar systems. The described lidar system transmits an initial signal having a first power level of an alternating pattern of power levels. The initial signal is associated with an initial pixel of consecutive pixels. The lidar system then transmits a subsequent signal, which is associated with a subsequent pixel of the consecutive pixels, having a second power level. The transmission of the initial signal and the subsequent signal with the alternating pattern of power levels limits a total power level emitted by the lidar system during a time interval to comply with safety regulations. The alternating pattern of power levels also permits the lidar system to switch between a long-detection range and a short-detection range for consecutive pixels.

Abstract: Provided is a silicon photomultiplier (SiPM) device and a silicon photomultiplier based LiDAR. The SiPM device includes a first sub-region and a second sub-region. In the first sub-region, the photodiode is operated with a first internal gain. In the second sub-region, the photodiode is operated with a second internal gain and the second internal gain in smaller than the first internal gain. A first anode generates current from the first sub-region in response to a low flux event, and the second anode generates current from the second sub-region in response to a high flux event. A common cathode outputs current generated from the first sub-region or the second sub-region.

Abstract: Provided are methods for Silicon Photomultiplier (SiPM)-based sensor for low-level fusion, which can include mitigating a Light Detection and Ranging (LiDAR) sensor processing path to provide high-confidence, low-level fusion between the camera (passive) and LiDAR (active) imaging. Systems and computer program products are also provided.

Abstract: Techniques and apparatuses are described that implement a low-cost readout module for a lidar system. The low-cost readout module includes a timing readout path and an intensity readout path, which are coupled to a receive channel of the lidar system. The timing readout path generates time-sensitive information using a threshold-triggered timing circuit, which can include a time-to-digital converter. The intensity readout path generates non-time-sensitive information using a hold-and-sample circuit, which can include a hold circuit and an analog-to-digital converter. By utilizing the threshold-triggered timing circuit to provide time-sensitive data and the hold-and-sample circuit to provide non-time-sensitive information, the readout module can have a lower cost than other readout modules that utilize a high-performance analog-to-digital converter for each receive channel.

Abstract: Various measurement systems and methods are disclosed to enable characterizing the optical characteristics of light beams emitted by a light detection and range finding (LIDAR) system or sensor and evaluating the range finding function of user selected lidar channels while the lidar operates under a real operational condition and is exposed to a range of user defined environmental conditions.

Abstract: Various measurement systems and methods are disclosed to enable characterizing the optical characteristics of light beams emitted by a light detection and range finding (LIDAR) system or sensor and evaluating the range finding function of user selected lidar channels while the lidar operates under a real operational condition and is exposed to a range of user defined environmental conditions.

Abstract: Provided are methods for Silicon Photomultiplier (SiPM)-based sensor for low-level fusion, which can include mitigating a Light Detection and Ranging (LiDAR) sensor processing path to provide high-confidence, low-level fusion between the camera (passive) and LiDAR (active) imaging. Systems and computer program products are also provided.

Abstract: Provided is a silicon photomultiplier (SiPM) device and a silicon photomultiplier based LiDAR. The SiPM device includes a first sub-region and a second sub-region. In the first sub-region, the photodiode is operated with a first internal gain. In the second sub-region, the photodiode is operated with a second internal gain and the second internal gain in smaller than the first internal gain. A first anode generates current from the first sub-region in response to a low flux event, and the second anode generates current from the second sub-region in response to a high flux event. A common cathode outputs current generated from the first sub-region or the second sub-region.

Abstract: This document describes techniques and systems to increase the dynamic range of time-of-flight (ToF) lidar systems. The described lidar system adjusts, based on the energy of a first return pulse, the bias voltage of a photodetector for other return pulses of the object pixel. The bias voltage can be adjusted down for highly-reflective or close-range objects. Similarly, the bias voltage can be increased for low-reflectivity or long-range objects. The ability of the described lidar system to adjust the bias voltage of the photodetector for each object pixel increases the dynamic range of the lidar system without additional hardware or a complex readout. The increased dynamic range allows the described lidar system to maintain a long-range capability, while accurately measuring return-pulse intensity for detecting close-range or highly-reflective objects.

Abstract: Provided are methods, systems, and computer program products for a LiDAR with an increased dynamic range. The method includes filtering output pulses of an SiPM device to a substantially symmetric pulse shape and capturing timing information and intensity information of the filtered output pulses for at least one predetermined intensity level. The method includes monitoring saturation of the SiPM device, wherein a width of a saturation plateau of a respective output pulse is determined in response to saturation of the SiPM device. The method also includes extrapolating additional timing information and additional intensity information of the respective output pulse using the captured timing information, the captured intensity information, and the determined width of the saturation plateau.

Abstract: The techniques of this disclosure enable lidar systems to operate as fast-scanning FMCW lidar systems. The fast-scanning lidar system alternates chirp patterns frame by frame as a way to increase scanning speed, without adding additional hardware. Each consecutive pair of frames includes a frame with a long chirp pattern with multiple chirps and a frame with a short chirp pattern with as few as a single chirp, which is derived from the long chirp pattern assuming a constant object velocity between frames. The chirp pattern applied to each pixel is consistent within each frame but different from one frame to the next. The combined duration of two consecutive frames is less than the combined duration of two consecutive frames of a traditional FMCW lidar system that uses the same chirp pattern from one frame to the next. The shorter duration increases frame rate, scanning speed, or overall throughput of the fast-scanning lidar system.