APPARATUSES, SYSTEMS, AND METHODS FOR DETERMINING GAS EMSSION RATE DETECTION SENSITIVITY AND GAS FLOW SPEED USING REMOTE GAS CONCENTRATION MEASUREMENTS
Apparatuses systems and methods for gas emission rate detection sensitivity and probability of detection (PoD) based on emission rate. A measurement system may be characterized by its ability to detect gas plumes as a function of the emission rate of those plumes. The measurement system may be characterized based on a generalized PoD function which expresses PoD relative to emission rate as a function of gas concentration noise and gas flow speed. In an example application, the PoD may be used to estimate a cumulative distribution of gas plumes which were not detected based on a cumulative distribution of measured gas plumes. In another example application, the PoD may be used to refine an estimate for a measured emission rate.
G01N 1/22 - Devices for withdrawing samples in the gaseous state
G01N 15/06 - Investigating concentration of particle suspensions
G01N 15/075 - Investigating concentration of particle suspensions by optical means
G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
G01N 21/88 - Investigating the presence of flaws, defects or contamination
G01N 33/00 - Investigating or analysing materials by specific methods not covered by groups
42 - Scientific, technological and industrial services, research and design
Goods & Services
Providing on-line non-downloadable software for use in collecting, aggregating, analyzing, storing, and visualizing gas emissions data; Providing on-line non-downloadable software for use in collecting, aggregating, analyzing, storing, and visualizing oil and gas right-of-way data; providing online non-downloadable software for use in gas emission measuring and analysis; Providing on-line non-downloadable software for use in oil and gas right-of-way data monitoring and analysis.
Embodiments of the disclosure are drawn to apparatuses and methods for determining gas flux measurements. A gas plume may be emitted from a source and may be blown by wind in an environment. A measurement system, such as a light detection and ranging (lidar) system may collect a plurality of gas concentration measurements associated with the gas plume at a plurality of locations in the environment. A gas flux may be determined based on one or more of the gas concentration measurements along with a wind speed at a location associated with the gas plume. In some embodiments, a height of the gas plume may be determined, and the wind speed at the height of the gas plume may be determined and used to determine the gas flux.
G01M 3/16 - Investigating fluid tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using electric detection means
G01N 33/00 - Investigating or analysing materials by specific methods not covered by groups
G01V 9/00 - Prospecting or detecting by methods not provided for in groups
G06F 17/18 - Complex mathematical operations for evaluating statistical data
5.
APPARATUSES, SYSTEMS, AND METHODS FOR GAS FLUX MEASUREMENTS WITH MOBILE PLATFORMS
Apparatuses, systems, and methods for open path laser spectroscopy with mobile platforms. An example system may include a first mobile platform and a second mobile platform, each of which supports a payload. A light beam directed from one payload to another may define a measurement path, which may be at a particular height above the ground. The payloads may determine a gas concentration along the measurement path. Wind information at the measurement height may be used to determine a gas flux. One or both of the mobile platforms may then move to a new location, and take a measurement along a new measurement path. By combining the measurement paths, gas flux through a flux surface may be determined.
G05D 1/00 - Control of position, course, altitude or attitude of land, water, air or space vehicles, e.g. using automatic pilots
B64C 39/02 - Aircraft not otherwise provided for characterised by special use
G01N 33/00 - Investigating or analysing materials by specific methods not covered by groups
G01P 5/02 - Measuring speed of fluids, e.g. of air streamMeasuring speed of bodies relative to fluids, e.g. of ship, of aircraft by measuring forces exerted by the fluid on solid bodies, e.g. anemometer
G01S 19/43 - Determining position using carrier phase measurements, e.g. kinematic positioningDetermining position using long or short baseline interferometry
B64U 101/00 - UAVs specially adapted for particular uses or applications
G01N 21/31 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
6.
APPARATUSES AND METHODS FOR A ROTATING OPTICAL REFLECTOR
Embodiments of the disclosure are drawn to apparatuses and methods for a rotating optical reflector. Optical systems may have a limited field of view, and so in order to expand the area that the optical system collects data from, the field of view of the optical system may be scanned across a target area. The present disclosure is directed to a rotating optical reflector, which includes a transmissive layer which refracts light onto a reflective layer, which has a normal which is not parallel to the axis about which the optical reflector is rotated. The optical reflector may be both statically and dynamically balanced, which may allow an increased size of the optical reflector, which in turn may increase the aperture of an optical system (e.g., a lidar system) using the rotating optical reflector.
Embodiments of the disclosure are drawn to apparatuses and methods for anomalous gas concentration detection. A spectroscopic system, such as a wavelength modulated spectroscopy (WMS) system may measure gas concentrations in a target area. However, noise, such as speckle noise, may interfere with measuring relatively low concentrations of gas, and may lead to false positives. A noise model, which includes a contribution from a speckle noise model, may be used to process data from the spectroscopic system. An adaptive threshold may be applied based on an expected amount of noise. A speckle filter may remove measurements which are outliers based on a measurement of their noise. Plume detection may be used to determine a presence of gas plumes. Each of these processing steps may be associated with a confidence, which may be used to determine an overall confidence in the processed measurements/gas plumes.
G01M 3/18 - Investigating fluid tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using electric detection means for pipes, cables, or tubesInvestigating fluid tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using electric detection means for pipe joints or sealsInvestigating fluid tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using electric detection means for valves
G01N 21/39 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using tunable lasers
Measurement apparatuses and methods are disclosed for generating high-precision and-accuracy gas concentration maps that can be overlaid with 3D topographic images by rapidly scanning one or several modulated laser beams with a spatially-encoded transmitter over a scene to build-up imagery. Independent measurements of the topographic target distance and path-integrated gas concentration are combined to yield a map of the path-averaged concentration between the sensor and each point in the image. This type of image is particularly useful for finding localized regions of elevated (or anomalous) gas concentration making it ideal for large-area leak detection and quantification applications including: oil and gas pipeline monitoring, chemical processing facility monitoring, and environmental monitoring.
G01N 21/39 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using tunable lasers
G01B 21/20 - Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant for measuring contours or curvatures, e.g. determining profile
G01C 15/00 - Surveying instruments or accessories not provided for in groups
G01M 3/28 - Investigating fluid tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipes, cables, or tubesInvestigating fluid tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipe joints or sealsInvestigating fluid tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for valves
G01M 3/38 - Investigating fluid tightness of structures by using light
G01N 21/17 - Systems in which incident light is modified in accordance with the properties of the material investigated
G01N 21/53 - Scattering, i.e. diffuse reflection within a body or fluid within a flowing fluid, e.g. smoke
G01P 5/00 - Measuring speed of fluids, e.g. of air streamMeasuring speed of bodies relative to fluids, e.g. of ship, of aircraft
Embodiments of the disclosure are drawn to apparatuses and methods for a rotating optical reflector. Optical systems may have a limited field of view, and so in order to expand the area that the optical system collects data from, the field of view of the optical system may be scanned across a target area. The present disclosure is directed to a rotating optical reflector, which includes a transmissive layer which refracts light onto a reflective layer, which has a normal which is not parallel to the axis about which the optical reflector is rotated. The optical reflector may be both statically and dynamically balanced, which may allow an increased size of the optical reflector, which in turn may increase the aperture of an optical system (e.g., a lidar system) using the rotating optical reflector.
Apparatuses, systems, and methods for determining gas emission rate detection sensitivity and gas flow speed using remote gas concentration measurements
Apparatuses systems and methods for gas emission rate detection sensitivity and probability of detection (PoD) based on emission rate. A measurement system may be characterized by its ability to detect gas plumes as a function of the emission rate of those plumes. The measurement system may be characterized based on a generalized PoD function which expresses PoD relative to emission rate as a function of gas concentration noise and gas flow speed. In an example application, the PoD may be used to estimate a cumulative distribution of gas plumes which were not detected based on a cumulative distribution of measured gas plumes. In another example application, the PoD may be used to refine an estimate for a measured emission rate.
G01N 1/22 - Devices for withdrawing samples in the gaseous state
G01N 15/06 - Investigating concentration of particle suspensions
G01N 15/075 - Investigating concentration of particle suspensions by optical means
G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
G01N 21/88 - Investigating the presence of flaws, defects or contamination
G01N 33/00 - Investigating or analysing materials by specific methods not covered by groups
11.
APPARATUSES, SYSTEMS, AND METHODS FOR DETERMINING GAS EMSSION RATE DETECTION SENSITIVITY AND GAS FLOW SPEED USING REMOTE GAS CONCENTRATION MEASUREMENTS
Apparatuses systems and methods for gas emission rate detection sensitivity and probability of detection (PoD) based on emission rate. A measurement system may be characterized by its ability to detect gas plumes as a function of the emission rate of those plumes. The measurement system may be characterized based on a generalized PoD function which expresses PoD relative to emission rate as a function of gas concentration noise and gas flow speed. In an example application, the PoD may be used to estimate a cumulative distribution of gas plumes which were not detected based on a cumulative distribution of measured gas plumes. In another example application, the PoD may be used to refine an estimate for a measured emission rate.
G06F 17/11 - Complex mathematical operations for solving equations
G01N 21/3504 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
12.
GAS-MAPPING 3D IMAGER MEASUREMENT TECHNIQUES AND METHOD OF DATA PROCESSING
Measurement approaches and data analysis methods are disclosed for combining 3D topographic data with spatially-registered gas concentration data to increase the efficiency of gas monitoring and leak detection tasks. Here, the metric for efficiency is defined as reducing the measurement time required to achieve the detection, or non-detection, of a gas leak with a desired confidence level. Methods are presented for localizing and quantifying detected gas leaks. Particular attention is paid to the combination of 3D spatial data with path-integrated gas concentration measurements acquired using remote gas sensing technologies, as this data can be used to determine the path-averaged gas concentration between the sensor and points in the measurement scene. Path-averaged gas concentration data is useful for finding and quantifying localized regions of elevated (or anomalous) gas concentration making it ideal for a variety of applications including: oil and gas pipeline monitoring, facility leak and emissions monitoring, and environmental monitoring.
G01B 21/20 - Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant for measuring contours or curvatures, e.g. determining profile
G01C 15/00 - Surveying instruments or accessories not provided for in groups
G01N 21/39 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using tunable lasers
G01M 3/28 - Investigating fluid tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipes, cables, or tubesInvestigating fluid tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipe joints or sealsInvestigating fluid tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for valves
G01M 3/38 - Investigating fluid tightness of structures by using light
G01N 21/53 - Scattering, i.e. diffuse reflection within a body or fluid within a flowing fluid, e.g. smoke
G01P 5/00 - Measuring speed of fluids, e.g. of air streamMeasuring speed of bodies relative to fluids, e.g. of ship, of aircraft
13.
Apparatuses, systems, and methods for gas flux measurements with mobile platforms
Apparatuses, systems, and methods for open path laser spectroscopy with mobile platforms. An example system may include a first mobile platform and a second mobile platform, each of which supports a payload. A light beam directed from one payload to another may define a measurement path, which may be at a particular height above the ground. The payloads may determine a gas concentration along the measurement path. Wind information at the measurement height may be used to determine a gas flux. One or both of the mobile platforms may then move to a new location, and take a measurement along a new measurement path. By combining the measurement paths, gas flux through a flux surface may be determined.
G05D 1/10 - Simultaneous control of position or course in three dimensions
B64C 39/02 - Aircraft not otherwise provided for characterised by special use
G01N 33/00 - Investigating or analysing materials by specific methods not covered by groups
G01P 5/02 - Measuring speed of fluids, e.g. of air streamMeasuring speed of bodies relative to fluids, e.g. of ship, of aircraft by measuring forces exerted by the fluid on solid bodies, e.g. anemometer
G01S 19/43 - Determining position using carrier phase measurements, e.g. kinematic positioningDetermining position using long or short baseline interferometry
G05D 1/00 - Control of position, course, altitude or attitude of land, water, air or space vehicles, e.g. using automatic pilots
B64U 101/00 - UAVs specially adapted for particular uses or applications
G01N 21/31 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
14.
High-sensitivity gas-mapping 3D imager and method of operation
Measurement apparatuses and methods are disclosed for generating high-precision and -accuracy gas concentration maps that can be overlaid with 3D topographic images by rapidly scanning one or several modulated laser beams with a spatially-encoded transmitter over a scene to build-up imagery. Independent measurements of the topographic target distance and path-integrated gas concentration are combined to yield a map of the path-averaged concentration between the sensor and each point in the image. This type of image is particularly useful for finding localized regions of elevated (or anomalous) gas concentration making it ideal for large-area leak detection and quantification applications including: oil and gas pipeline monitoring, chemical processing facility monitoring, and environmental monitoring.
G01N 21/39 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using tunable lasers
G01N 21/53 - Scattering, i.e. diffuse reflection within a body or fluid within a flowing fluid, e.g. smoke
G01B 21/20 - Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant for measuring contours or curvatures, e.g. determining profile
G01C 15/00 - Surveying instruments or accessories not provided for in groups
G01M 3/28 - Investigating fluid tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipes, cables, or tubesInvestigating fluid tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipe joints or sealsInvestigating fluid tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for valves
G01M 3/38 - Investigating fluid tightness of structures by using light
G01P 5/00 - Measuring speed of fluids, e.g. of air streamMeasuring speed of bodies relative to fluids, e.g. of ship, of aircraft
G01N 21/17 - Systems in which incident light is modified in accordance with the properties of the material investigated
15.
Apparatuses and methods for anomalous gas concentration detection
Embodiments of the disclosure are drawn to apparatuses and methods for anomalous gas concentration detection. A spectroscopic system, such as a wavelength modulated spectroscopy (WMS) system may measure gas concentrations in a target area. However, noise, such as speckle noise, may interfere with measuring relatively low concentrations of gas, and may lead to false positives. A noise model, which includes a contribution from a speckle noise model, may be used to process data from the spectroscopic system. An adaptive threshold may be applied based on an expected amount of noise. A speckle filter may remove measurements which are outliers based on a measurement of their noise. Plume detection may be used to determine a presence of gas plumes. Each of these processing steps may be associated with a confidence, which may be used to determine an overall confidence in the processed measurements/gas plumes.
G01M 3/18 - Investigating fluid tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using electric detection means for pipes, cables, or tubesInvestigating fluid tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using electric detection means for pipe joints or sealsInvestigating fluid tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using electric detection means for valves
G01N 21/39 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using tunable lasers
Embodiments of the present disclosure are drawn to apparatuses, systems, and methods for range peak pairing and high accuracy target tracking using frequency-modulated continuous-wave (FMCW) light detection and ranging (LiDAR). A laser source may illuminate a target with a first laser chirp pair during a first time period and a second laser chirp pair during a second time period. Based on the configuration of the chirps between the pairs and within the pairs, properties of the target may be determined. For example, range estimates may be made based on each chirp pair, and those estimates may be averaged to cancel out a Doppler shift error. In another example, the Doppler shift may be determined, which may increase the accuracy of a range measurement and/or be used to identify which peaks are associated with a given target.
G01S 17/34 - Systems determining position data of a target for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated 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
17.
Apparatuses and methods for a rotating optical reflector
Embodiments of the disclosure are drawn to apparatuses and methods for a rotating optical reflector. Optical systems may have a limited field of view, and so in order to expand the area that the optical system collects data from, the field of view of the optical system may be scanned across a target area. The present disclosure is directed to a rotating optical reflector, which includes a transmissive layer which refracts light onto a reflective layer, which has a normal which is not parallel to the axis about which the optical reflector is rotated. The optical reflector may be both statically and dynamically balanced, which may allow an increased size of the optical reflector, which in turn may increase the aperture of an optical system (e.g., a lidar system) using the rotating optical reflector.
Embodiments of the disclosure are drawn to apparatus and methods for determining gas flux measurements. A gas plume may be emitted from a source and may be blown by wind in an environment. A measurement system, such as a light detection and ranging (lidar) system may collect a plurality of gas concentration measurements associated with the gas plume at a plurality of locations in the environment. A gas flux may be determined based on one or more of the gas concentration measurements along with a wind speed at a location associated with the gas plume. In some embodiments, a height of the gas plume may be determined, and the wind speed at the height of the gas plume may be determined and used to determine the gas flux.
G01M 3/16 - Investigating fluid tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using electric detection means
G01N 33/00 - Investigating or analysing materials by specific methods not covered by groups
G01V 9/00 - Prospecting or detecting by methods not provided for in groups
G06F 17/18 - Complex mathematical operations for evaluating statistical data
19.
Apparatuses and methods for anomalous gas concentration detection
Embodiments of the disclosure are drawn to apparatuses and methods for anomalous gas concentration detection. A spectroscopic system, such as a wavelength modulated spectroscopy (WMS) system may measure gas concentrations in a target area. However, noise, such as speckle noise, may interfere with measuring relatively low concentrations of gas, and may lead to false positives. A noise model, which includes a contribution from a speckle noise model, may be used to process data from the spectroscopic system. An adaptive threshold may be applied based on an expected amount of noise. A speckle filter may remove measurements which are outliers based on a measurement of their noise. Plume detection may be used to determine a presence of gas plumes. Each of these processing steps may be associated with a confidence, which may be used to determine an overall confidence in the processed measurements/gas plumes.
G01N 21/39 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using tunable lasers
Examples are provided that use multiple analog-to-digital converters (ADCs) to disambiguate FMCW ladar range returns from one or more targets that may be greater than the Nyquist frequencies of one or more of the ADCs. Examples are also provided that use a first and a second laser FMCW return signal (e.g., reflected beam) in combination with two or more ADCs to disambiguate one or more target ranges (e.g., distances to one or more objects).
G01S 17/34 - Systems determining position data of a target for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated 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 7/4913 - Circuits for detection, sampling, integration or read-out
21.
Processing temporal segments of laser chirps and examples of use in FMCW LiDAR methods and apparatuses
Examples of FMCW laser radar systems and methods described herein may segment the processing of a broader bandwidth frequency chirp into multiple shorter-duration (e.g., lower bandwidth) frequency chirps. This segmentation may have the benefits in some examples of improving the measurement duty cycle and range resolution, and/or allowing for more flexible processing, and/or enabling improved detection of more distant objects.
G01S 17/34 - Systems determining position data of a target for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated 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
22.
APPARATUSES, SYSTEMS, AND METHODS FOR GAS FLUX MEASUREMENTS WITH MOBILE PLATFORMS
Apparatuses, systems, and methods for open path laser spectroscopy with mobile platforms. An example system may include a first mobile platform and a second mobile platform, each of which supports a payload. A light beam directed from one payload to another may define a measurement path, which may be at a particular height above the ground. The payloads may determine a gas concentration along the measurement path. Wind information at the measurement height may be used to determine a gas flux. One or both of the mobile platforms may then move to a new location, and take a measurement along a new measurement path. By combining the measurement paths, gas flux through a flux surface may be determined.
Measurement approaches and data analysis methods are disclosed for combining 3D topographic data with spatially-registered gas concentration data to increase the efficiency of gas monitoring and leak detection tasks. Here, the metric for efficiency is defined as reducing the measurement time required to achieve the detection, or non-detection, of a gas leak with a desired confidence level. Methods are presented for localizing and quantifying detected gas leaks. Particular attention is paid to the combination of 3D spatial data with path-integrated gas concentration measurements acquired using remote gas sensing technologies, as this data can be used to determine the path-averaged gas concentration between the sensor and points in the measurement scene. Path-averaged gas concentration data is useful for finding and quantifying localized regions of elevated (or anomalous) gas concentration making it ideal for a variety of applications including: oil and gas pipeline monitoring, facility leak and emissions monitoring, and environmental monitoring.
G06K 9/00 - Methods or arrangements for reading or recognising printed or written characters or for recognising patterns, e.g. fingerprints
G01B 21/20 - Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant for measuring contours or curvatures, e.g. determining profile
G01C 15/00 - Surveying instruments or accessories not provided for in groups
G01N 21/39 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using tunable lasers
G01M 3/28 - Investigating fluid tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipes, cables, or tubesInvestigating fluid tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipe joints or sealsInvestigating fluid tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for valves
G01M 3/38 - Investigating fluid tightness of structures by using light
G01N 21/53 - Scattering, i.e. diffuse reflection within a body or fluid within a flowing fluid, e.g. smoke
G01P 5/00 - Measuring speed of fluids, e.g. of air streamMeasuring speed of bodies relative to fluids, e.g. of ship, of aircraft
G01N 21/17 - Systems in which incident light is modified in accordance with the properties of the material investigated
09 - Scientific and electric apparatus and instruments
42 - Scientific, technological and industrial services, research and design
Goods & Services
Downloadable reports and downloadable display maps containing measured information acquired by sensors pertaining to oil and gas, waste management, or agriculture infrastructure and sites Platform as a service (PAAS) featuring software which allows users to input parameters to measure or display information acquired by sensors pertaining to oil and gas, waste management, or agriculture infrastructure and sites; Platform as a service (PAAS) featuring software for the transmission and receipt of reports or data comprising measured information acquired by sensors pertaining to oil and gas, waste management, or agriculture infrastructure and sites; Platform as a service (PAAS) featuring software for operations management tools in the fields of oil and gas, waste management, or agriculture infrastructure and sites, namely, the generation of alerts and work orders
25.
METHODS AND APPARATUSES FOR RANGE PEAK PAIRING AND HIGH-ACCURACY TARGET TRACKING USING FMCW LADAR MEASUREMENTS
Embodiments of the present disclosure are drawn to apparatuses, systems, and methods for range peak pairing and high accuracy target tracking using frequency-modulated continuous-wave (FMCW) light detection and ranging (LiDAR). A laser source may illuminate a target with a first laser chirp pair during a first time period and a second laser chirp pair during a second time period. Based on the configuration of the chirps between the pairs and within the pairs, properties of the target may be determined. For example, range estimates may be made based on each chirp pair, and those estimates may be averaged to cancel out a Doppler shift error. In another example, the Doppler shift may be determined, which may increase the accuracy of a range measurement and/or be used to identify which peaks are associated with a given target.
Methods and apparatuses are described for frequency-modulated continuous-wave (FMCW) light detection and ranging (LiDAR). Examples are provided where high-closed-loop bandwidth, active feedback applied to laser frequency chirps may provide increases in the free-running laser coherence length for long-range FMCW distance measurements. Examples are provided that use an asymmetric sideband generator within an active feedback loop for higher closed-loop bandwidth. Examples of using a single shared reference interferometer within multiple active feedback loops that may be used for increasing the coherence length of multiple chirped lasers are described. Example calibrators are also described.
G01C 3/00 - Measuring distances in line of sightOptical rangefinders
G01S 17/34 - Systems determining position data of a target for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated 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
Length metrology apparatuses and methods are disclosed for measuring both specular and non-specular surfaces with high accuracy and precision, and with suppressed phase induced distance errors. In one embodiment, a system includes a laser source exhibiting a first and second laser outputs with optical frequencies that are modulated linearly over large frequency ranges. The system further includes calibration and signal processing portions configured to determine a calibrated distance to at least one sample.
H04B 10/071 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using a reflected signal, e.g. using optical time domain reflectometers [OTDR]
H04B 10/079 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using an in-service signal using measurements of the data signal
Measurement apparatuses and methods are disclosed for generating high-precision and -accuracy gas concentration maps that can be overlaid with 3D topographic images by rapidly scanning one or several modulated laser beams with a spatially-encoded transmitter over a scene to build-up imagery. Independent measurements of the topographic target distance and path-integrated gas concentration are combined to yield a map of the path-averaged concentration between the sensor and each point in the image. This type of image is particularly useful for finding localized regions of elevated (or anomalous) gas concentration making it ideal for large-area leak detection and quantification applications including: oil and gas pipeline monitoring, chemical processing facility monitoring, and environmental monitoring.
G01B 21/20 - Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant for measuring contours or curvatures, e.g. determining profile
G01C 15/00 - Surveying instruments or accessories not provided for in groups
G01N 21/39 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using tunable lasers
G01M 3/28 - Investigating fluid tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipes, cables, or tubesInvestigating fluid tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipe joints or sealsInvestigating fluid tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for valves
G01M 3/38 - Investigating fluid tightness of structures by using light
G01N 21/53 - Scattering, i.e. diffuse reflection within a body or fluid within a flowing fluid, e.g. smoke
G01P 5/00 - Measuring speed of fluids, e.g. of air streamMeasuring speed of bodies relative to fluids, e.g. of ship, of aircraft
G06K 9/00 - Methods or arrangements for reading or recognising printed or written characters or for recognising patterns, e.g. fingerprints
G01N 21/17 - Systems in which incident light is modified in accordance with the properties of the material investigated
Embodiments of the disclosure are drawn to apparatuses and methods for determining gas flux measurements. A gas plume may be emitted from a source and may be blown by wind in an environment. A measurement system, such as a light detection and ranging (lidar) system may collect a plurality of gas concentration measurements associated with the gas plume at a plurality of locations in the environment. A gas flux may be determined based on one or more of the gas concentration measurements along with a wind speed at a location associated with the gas plume. In some embodiments, a height of the gas plume may be determined, and the wind speed at the height of the gas plume may be determined and used to determine the gas flux.
G01M 3/04 - Investigating fluid tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point
G06F 19/00 - Digital computing or data processing equipment or methods, specially adapted for specific applications (specially adapted for specific functions G06F 17/00;data processing systems or methods specially adapted for administrative, commercial, financial, managerial, supervisory or forecasting purposes G06Q;healthcare informatics G16H)
30.
Accurate chirped synthetic wavelength interferometer
A system is provided for measuring distance or displacement, comprising: first and second laser sources configured to provide first and second laser outputs; a beam combiner configured to receive and combine at least part of the first and second laser outputs into a combined laser output; a signal calibrator configured to receive at least part of the first laser output, the second laser output, or the combined laser output, and output a calibration signal; a plurality of optical paths, including a first optical path, a second optical path, the plurality of optical paths being configured to direct at least part of the combined beam onto an optical detector to produce an interference signal; and a signal processor configured to receive the interference signal and determine a pathlength difference between the first and second optical paths.
G01B 11/02 - Measuring arrangements characterised by the use of optical techniques for measuring length, width, or thickness
H04B 10/071 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using a reflected signal, e.g. using optical time domain reflectometers [OTDR]
H04B 10/079 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using an in-service signal using measurements of the data signal
Embodiments of the disclosure are drawn to apparatuses and methods for anomalous gas concentration detection. A spectroscopic system, such as a wavelength modulated spectroscopy (WMS) system may measure gas concentrations in a target area. However, noise, such as speckle noise, may interfere with measuring relatively low concentrations of gas, and may lead to false positives. A noise model, which includes a contribution from a speckle noise model, may be used to process data from the spectroscopic system. An adaptive threshold may be applied based on an expected amount of noise. A speckle filter may remove measurements which are outliers based on a measurement of their noise. Plume detection may be used to determine a presence of gas plumes. Each of these processing steps may be associated with a confidence, which may be used to determine an overall confidence in the processed measurements/gas plumes.
G01M 3/28 - Investigating fluid tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipes, cables, or tubesInvestigating fluid tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipe joints or sealsInvestigating fluid tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for valves
G06K 9/00 - Methods or arrangements for reading or recognising printed or written characters or for recognising patterns, e.g. fingerprints
32.
APPARATUSES AND METHODS FOR A ROTATING OPTICAL REFLECTOR
Embodiments of the disclosure are drawn to apparatuses and methods for a rotating optical reflector. Optical systems may have a limited field of view, and so in order to expand the area that the optical system collects data from, the field of view of the optical system may be scanned across a target area. The present disclosure is directed to a rotating optical reflector, which includes a transmissive layer which refracts light onto a reflective layer, which has a normal which is not parallel to the axis about which the optical reflector is rotated. The optical reflector may be both statically and dynamically balanced, which may allow an increased size of the optical reflector, which in turn may increase the aperture of an optical system (e.g., a lidar system) using the rotating optical reflector.
Examples of FMCW laser radar systems and methods described herein may segment the processing of a broader bandwidth frequency chirp into multiple shorter-duration (e.g., lower bandwidth) frequency chirps. This segmentation may have the benefits in some examples of improving the measurement duty cycle and range resolution, and/or allowing for more flexible processing, and/or enabling improved detection of more distant objects.
G01S 13/34 - Systems for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated 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 15/34 - Systems for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated 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 17/06 - Systems determining position data of a target
G01S 17/32 - Systems determining position data of a target for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated
34.
DIGITIZATION SYSTEMS AND TECHNIQUES AND EXAMPLES OF USE IN FMCW LIDAR METHODS AND APPARATUSES
Examples are provided that use multiple analog-to-digital converters (ADCs) to disambiguate FMCW ladar range returns from one or more targets that may be greater than the Nyquist frequencies of one or more of the ADCs. Examples are also provided that use a first and a second laser FMCW return signal (e.g., reflected beam) in combination with two or more ADCs to disambiguate one or more target ranges (e.g., distances to one or more objects).
Methods and apparatuses are described for frequency-modulated continuous-wave (FMCW) light detection and ranging (LiDAR). Examples are provided where high-closed-loop bandwidth, active feedback applied to laser frequency chirps may provide increases in the free-running laser coherence length for long-range FMCW distance measurements. Examples are provided that use an asymmetric sideband generator within an active feedback loop for higher closed-loop bandwidth. Examples of using a single shared reference interferometer within multiple active feedback loops that may be used for increasing the coherence length of multiple chirped lasers are described. Example calibrators are also described.
G01S 17/02 - Systems using the reflection of electromagnetic waves other than radio waves
G01S 17/06 - Systems determining position data of a target
G01S 17/08 - Systems determining position data of a target for measuring distance only
G01S 17/10 - Systems determining position data of a target for measuring distance only using transmission of interrupted, pulse-modulated waves
G01S 17/32 - Systems determining position data of a target for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated
G01S 17/36 - Systems determining position data of a target for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated with phase comparison between the received signal and the contemporaneously transmitted signal
G01S 17/42 - Simultaneous measurement of distance and other coordinates
36.
High-sensitivity gas-mapping 3D imager and method of operation
Measurement apparatuses and methods are disclosed for generating high-precision and -accuracy gas concentration maps that can be overlaid with 3D topographic images by rapidly scanning one or several modulated laser beams with a spatially-encoded transmitter over a scene to build-up imagery. Independent measurements of the topographic target distance and path-integrated gas concentration are combined to yield a map of the path-averaged concentration between the sensor and each point in the image. This type of image is particularly useful for finding localized regions of elevated (or anomalous) gas concentration making it ideal for large-area leak detection and quantification applications including: oil and gas pipeline monitoring, chemical processing facility monitoring, and environmental monitoring.
G01B 21/20 - Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant for measuring contours or curvatures, e.g. determining profile
G01M 3/28 - Investigating fluid tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipes, cables, or tubesInvestigating fluid tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipe joints or sealsInvestigating fluid tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for valves
G01M 3/38 - Investigating fluid tightness of structures by using light
G01N 21/53 - Scattering, i.e. diffuse reflection within a body or fluid within a flowing fluid, e.g. smoke
G01P 5/00 - Measuring speed of fluids, e.g. of air streamMeasuring speed of bodies relative to fluids, e.g. of ship, of aircraft
G06K 9/00 - Methods or arrangements for reading or recognising printed or written characters or for recognising patterns, e.g. fingerprints
G01C 15/00 - Surveying instruments or accessories not provided for in groups
G01N 21/39 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using tunable lasers
G01N 21/17 - Systems in which incident light is modified in accordance with the properties of the material investigated
37.
Length metrology apparatus and methods for suppressing phase noise-induced distance measurement errors
Length metrology apparatuses and methods are disclosed for measuring both specular and non-specular surfaces with high accuracy and precision, and with suppressed phase induced distance errors. In one embodiment, a system includes a laser source exhibiting a first and second laser outputs with optical frequencies that are modulated linearly over large frequency ranges. The system further includes calibration and signal processing portions configured to determine a calibrated distance to at least one sample.
G01B 11/02 - Measuring arrangements characterised by the use of optical techniques for measuring length, width, or thickness
H04B 10/071 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using a reflected signal, e.g. using optical time domain reflectometers [OTDR]
H04B 10/079 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using an in-service signal using measurements of the data signal
Measurement approaches and data analysis methods are disclosed for combining 3D topographic data with spatially-registered gas concentration data to increase the efficiency of gas monitoring and leak detection tasks. Here, the metric for efficiency is defined as reducing the measurement time required to achieve the detection, or non-detection, of a gas leak with a desired confidence level. Methods are presented for localizing and quantifying detected gas leaks. Particular attention is paid to the combination of 3D spatial data with path-integrated gas concentration measurements acquired using remote gas sensing technologies, as this data can be used to determine the path-averaged gas concentration between the sensor and points in the measurement scene. Path-averaged gas concentration data is useful for finding and quantifying localized regions of elevated (or anomalous) gas concentration making it ideal for a variety of applications including: oil and gas pipeline monitoring, facility leak and emissions monitoring, and environmental monitoring.
G01B 21/20 - Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant for measuring contours or curvatures, e.g. determining profile
G01M 3/28 - Investigating fluid tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipes, cables, or tubesInvestigating fluid tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipe joints or sealsInvestigating fluid tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for valves
G01M 3/38 - Investigating fluid tightness of structures by using light
G01N 21/53 - Scattering, i.e. diffuse reflection within a body or fluid within a flowing fluid, e.g. smoke
G01P 5/00 - Measuring speed of fluids, e.g. of air streamMeasuring speed of bodies relative to fluids, e.g. of ship, of aircraft
G06K 9/00 - Methods or arrangements for reading or recognising printed or written characters or for recognising patterns, e.g. fingerprints
G01C 15/00 - Surveying instruments or accessories not provided for in groups
G01N 21/39 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using tunable lasers
G01N 21/17 - Systems in which incident light is modified in accordance with the properties of the material investigated
39.
High-sensitivity gas-mapping 3D imager and method of operation
Measurement apparatuses and methods are disclosed for generating high-precision and -accuracy gas concentration maps that can be overlaid with 3D topographic images by rapidly scanning one or several modulated laser beams with a spatially-encoded transmitter over a scene to build-up imagery. Independent measurements of the topographic target distance and path-integrated gas concentration are combined to yield a map of the path-averaged concentration between the sensor and each point in the image. This type of image is particularly useful for finding localized regions of elevated (or anomalous) gas concentration making it ideal for large-area leak detection and quantification applications including: oil and gas pipeline monitoring, chemical processing facility monitoring, and environmental monitoring.
G01N 21/00 - Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
G01B 21/20 - Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant for measuring contours or curvatures, e.g. determining profile
G01M 3/28 - Investigating fluid tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipes, cables, or tubesInvestigating fluid tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipe joints or sealsInvestigating fluid tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for valves
G01M 3/38 - Investigating fluid tightness of structures by using light
G01N 21/53 - Scattering, i.e. diffuse reflection within a body or fluid within a flowing fluid, e.g. smoke
G01P 5/00 - Measuring speed of fluids, e.g. of air streamMeasuring speed of bodies relative to fluids, e.g. of ship, of aircraft
G06K 9/00 - Methods or arrangements for reading or recognising printed or written characters or for recognising patterns, e.g. fingerprints
G01C 15/00 - Surveying instruments or accessories not provided for in groups
G01N 21/39 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using tunable lasers
G01N 21/17 - Systems in which incident light is modified in accordance with the properties of the material investigated
09 - Scientific and electric apparatus and instruments
Goods & Services
Gas sensors for measuring gas concentration; Laser detectors for measuring distance and gases; Laser doppler for measuring purposes; Laser equipment for non-medical purposes; Laser measuring systems; Laser object detectors for use on vehicles; Laser rangefinders; Laser scanners for industrial inspection; Lasers for industrial use; Lasers for measuring purposes; Lidar; Three dimensional (3D) scanners; Measuring apparatus, namely, laser distance meters
41.
ACCURATE CHIRPED SYNTHETIC WAVELENGTH INTERFEROMETER
A system is provided for measuring distance or displacement, comprising: first and second laser sources configured to provide first and second laser outputs; a beam combiner configured to receive and combine at least part of the first and second laser outputs into a combined laser output; a signal calibrator configured to receive at least part of the first laser output, the second laser output, or the combined laser output, and output a calibration signal; a plurality of optical paths, including a first optical path, a second optical path, the plurality of optical paths being configured to direct at least part of the combined beam onto an optical detector to produce an interference signal; and a signal processor configured to receive the interference signal and determine a pathlength difference between the first and second optical paths.
Length metrology apparatuses and methods are disclosed for measuring both specular and non-specular surfaces with high accuracy and precision, and with suppressed phase induced distance errors. In one embodiment, a system includes a laser source exhibiting a first and second laser outputs with optical frequencies that are modulated linearly over large frequency ranges. The system further includes calibration and signal processing portions configured to determine a calibrated distance to at least one sample.
Length metrology apparatuses and methods are disclosed for measuring both specular and non-specular surfaces with high accuracy and precision, and with suppressed phase induced distance errors. In one embodiment, a system includes a laser source exhibiting a first and second laser outputs with optical frequencies that are modulated linearly over large frequency ranges. The system further includes calibration and signal processing portions configured to determine a calibrated distance to at least one sample.
H04B 10/071 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using a reflected signal, e.g. using optical time domain reflectometers [OTDR]
H04B 10/079 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using an in-service signal using measurements of the data signal
A system is provided for measuring distance or displacement, comprising: first and second laser sources configured to provide first and second laser outputs; a beam combiner configured to receive and combine at least part of the first and second laser outputs into a combined laser output; a signal calibrator configured to receive at least part of the first laser output, the second laser output, or the combined laser output, and output a calibration signal; a plurality of optical paths, including a first optical path, a second optical path, the plurality of optical paths being configured to direct at least part of the combined beam onto an optical detector to produce an interference signal; and a signal processor configured to receive the interference signal and determine a pathlength difference between the first and second optical paths.
G01B 11/02 - Measuring arrangements characterised by the use of optical techniques for measuring length, width, or thickness
H04B 10/071 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using a reflected signal, e.g. using optical time domain reflectometers [OTDR]
H04B 10/079 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using an in-service signal using measurements of the data signal
A method and apparatus are described including a laser with a plurality of internal or external actuators for affecting an optical frequency of light output by the laser, wherein the plurality of actuators have a corresponding plurality of different frequency response bands for changing optical properties of the laser and a corresponding plurality of actuation ranges of optical frequencies affected. Also included is an optical detector, and a plurality of optical paths configured to direct light output by the laser onto the detector. A laser controller is configured to provide a plurality of inputs to the plurality of actuators based on a detector signal output from the optical detector and the corresponding frequency response bands and actuation ranges.
H01S 3/10 - Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
H01S 3/13 - Stabilisation of laser output parameters, e.g. frequency or amplitude
H01S 5/0683 - Stabilisation of laser output parameters by monitoring the optical output parameters
09 - Scientific and electric apparatus and instruments
Goods & Services
Laser detectors for measuring distance and gases; Laser doppler for measuring purposes; Laser equipment for non-medical purposes; Laser measuring systems; Laser rangefinders; Laser scanners for industrial inspection; Lasers for industrial use; Lasers for measuring purposes; Lasers for non-medical purposes; Lasers not for medical use; Lidar; Measuring apparatus, namely, laser distance meters
09 - Scientific and electric apparatus and instruments
Goods & Services
Laser detectors for measuring distance and gases; Laser doppler for measuring purposes; Laser equipment for non-medical purposes; Laser measuring systems; Laser rangefinders; Laser scanners for industrial inspection; Lasers for industrial use; Lasers for measuring purposes; Lasers for non-medical purposes; Lasers not for medical use; Lidar; Measuring apparatus, namely, laser distance meters
A method, apparatus and computer-readable storage medium are described for a tunable laser source that produces a desired frequency modulated optical waveform with a precision within 0.01 percent over a bandwidth greater than about 50 gigaHertz. An apparatus includes a tunable laser having one or more drive inputs for affecting an optical frequency of light output by the laser; and an optical detector. Multiple optical paths are configured to direct light output by the laser onto the optical detector. A laser controller is configured to provide to a drive input a loopback signal based on a measured or predetermined difference in optical dispersion among the plurality of optical paths and a detector signal output from the optical detector. In some embodiments, a ranging device includes the tunable laser source.
H01S 3/10 - Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
H01S 3/13 - Stabilisation of laser output parameters, e.g. frequency or amplitude
