Class / Patent application number | Description | Number of patent applications / Date published |
356500090 | Of frequency difference | 36 |
20080239281 | ABSOLUTE DISTANCE METER - An absolute distance meter for measuring a distance to a target may include a synthesizer including a first quadrature modulator and structured to receive a reference signal having a reference frequency and output a first signal having a first frequency and a second signal having a second frequency, a laser structured to output a laser beam, wherein the laser beam is modulated by the second signal, an optical system for directing the laser beam toward the target, a reference phase calculating system structured to calculate a reference phase based on signals having the first frequency and the second frequency, a target optical detector structured to receive at least a portion of the laser beam returned from the target and structured to output a measured electrical signal having the second frequency based on the at least a portion of the laser beam, and a measure phase calculating system structured to calculate a measure phase based on the measured electrical signal and the first signal. | 10-02-2008 |
20080246944 | Photon counting, chirped AM LADAR system and related methods - Ladar systems and methods are provided. One embodiment is a ladar system comprising: a chirp generator for generating a chirped waveform; a laser for transmitting a light signal toward a target, the light signal being modulated by the chirped waveform; and a photon-counting sensor for receiving a temporally-modulated photon stream corresponding to the modulated light signal being reflected from the target and toward the ladar system, the photon-counting sensor gated relative to the chirped waveform. | 10-09-2008 |
20090002679 | SYSTEMS FOR DOPPLER TRACKING USING PHOTONIC MIXING DETECTORS - Ladar systems are provided. An exemplary ladar system includes a waveform generator for generating an arbitrary waveform, a laser for transmitting a modulated light signal toward a target, and a Doppler tracking loop for tracking the Doppler frequency shift between the transmitted light signal and a received reflected light signal. | 01-01-2009 |
20090002680 | CHIRPED AMPLITUDE MODULATION LADAR - An imaging method and apparatus using an unmodulated pulsed laser with a chirp modulated receiver is provided for producing 3D plus intensity imagery of targets in heavily cluttered locations The apparatus includes a laser for emitting a laser beam and synchronizing a receiver to receive a reflected laser signal and transform the reflected laser signal into a displayable image that includes intensity information. | 01-01-2009 |
20090091739 | LASER MEASURING DEVICE - A laser measuring device maintains high responsivity irrespective of changes in surrounding environment, provides more correct measurement and long distance measurement due to reduced noise, and ensures the safety and reliability of a product. A first light emitter emits first wavelength light having a first wavelength. A second light emitter emits second wavelength light having a second wavelength, the second light emitter being arranged perpendicular to the first light emitter. An optical mirror allows one of the first wavelength light and the second wavelength light to pass but reflecting the other one. A first band pass filter for allows the first wavelength light to pass. A second band pass filter allows the second wavelength light to pass. A light receiver receives incident light, which arrives through one of the first and second band pass filters. A controller activates at least one of the first and second light emitters. | 04-09-2009 |
20090122297 | RANGE IMAGE GENERATING APPARATUS - A range image generating apparatus capable of preventing or reducing generation of range images with interference which contain e.g., pixels with erroneous distance values is provided. The range image generating apparatus includes: a light source radiating a light; an image pickup element; a range image generating unit; a frequency changing unit that changes a modulation frequency for each frame rate or charge storage time; and a control unit that controls the light source and the image pickup element in synchronization with the modulation frequency changed by the frequency changing unit. | 05-14-2009 |
20090303458 | DEVICE AND METHOD FOR MEASURING RELATIVE MOVEMENT - A device for measuring movement of an object ( | 12-10-2009 |
20100208236 | METHOD FOR DETERMINING THE POSITION OF AN OBJECT IN A STRUCTURE - This invention relates to a method for determining the position of an object in a structure. The object receives modulated light waves from a plurality of light sources, which are arranged in the structure. The modulation is individually coded, and the position of the light sources in the structure is known. The modulation signals are synchronized, and thereby it is possible to determine the position of the object on basis of measuring the phase difference between the phase of each received modulated light wave and a comparison phase. The phase difference is used for distance calculations, which in turn give the position of the object. | 08-19-2010 |
20100265491 | RANGE-FINDING METHOD AND APPARATUS - Range-finding apparatus comprises a source of pulsed radiation of variable repetition rate and a beam-splitter for dividing the pulsed radiation into two portions which are directed respectively to a local retro-reflector and to a retro-reflector co-located with a remote target the range of which is to be determined. The source, beam-splitter and retro-reflectors are arranged in the form of Michelson interferometer together with a detector. The repetition rate of the source is tuned to frequencies f such that round-trip distance to the remote target is mc/f where m is an integer, this condition being detected by observing a heterodyne signal at the detector. Two such frequencies enable range to be determined. The precision with which range is determined may be increased by carrying out interferometry using the two portions. The accuracy of the method does not depend on absolute range (as with triangulation) and is not limited by the speed of timing electronics, as is the case for time-of-flight techniques. | 10-21-2010 |
20100271617 | VEHICLE POSITIONING MEASUREMENT SYSTEM AND METHOD - A vehicle position measurement system ( | 10-28-2010 |
20100315619 | ELECTRO-OPTICAL DISTANCE-MEASURING UNIT - An electro-optical distance-measuring unit ( | 12-16-2010 |
20110051122 | OPTOELECTRONIC RANGE FINDER - A device for optoelectronic distance measurement includes an emitter having a first end for emitting a measuring beam to an object to be measured and a second end, a receiver for receiving the measuring beam reflected or dispersed back from the object to be measured and for converting it to a measurement signal, a signal processing device for filtering the measurement signal and a reference signal, and a control and analysis device for analyzing the information of the measurement signal and the reference signal so as to determine the distance from the object to be measured. The second end of the emitter is used to emit a reference beam which is received by the receiver and converted to form the reference signal. | 03-03-2011 |
20110085155 | LADAR TRANSMITTING AND RECEIVING SYSTEM AND METHOD - A compact LADAR transmitting and receiving apparatus includes a pulse laser generating pulses of light; a transmitter collimating and directing the pulses of light toward a target; a receiver collecting reflected pulses of light, the reflected pulses of light having been reflected from the target, the receiver comprising a tapered fiber bundle; a sensor operatively connected to the tapered fiber bundle, where the sensor comprises a photosensitive region and outputs a photocurrent; an amplifier amplifying the photocurrent; and a power divider splitting the amplified photocurrent between a high gain channel and a low gain channel; a RF interface accepting the high gain channel, the low gain channel, and an undelayed sample of a pulse of light generated from the pulse laser as input; a processing unit accepting output from the RF interface; and a display unit displaying output from the processing unit. | 04-14-2011 |
20110205523 | COMPACT FIBER OPTIC GEOMETRY FOR A COUNTER CHIRP FMCW COHERENT LASER RADAR - A system and method for determining a measured distance between a measuring device ( | 08-25-2011 |
20110228254 | PHYSICAL QUANTITY SENSOR AND PHYSICAL QUANTITY MEASURING METHOD - A physical quantity sensor includes: a semiconductor laser which emits laser light to a measurement target; an oscillation wavelength modulating device that operates the semiconductor laser such that at least one of a first oscillation period and a second oscillation period alternately exists; a detector that detects an electrical signal including interference waveforms, the interference waveforms being caused by a self-coupling effect of the laser light and return light from the measurement target; a signal extracting device that measures each cycle of the interference waveforms whenever the interference waveform is input; a cycle correcting device that compares each cycle of the interference waveforms with a reference cycle to correct the cycles of the interference waveforms; and a calculating device that calculates at least one of displacement and velocity of the measurement target based on each of the cycles of the interference waveforms corrected by the cycle correcting device. | 09-22-2011 |
20110317147 | Time Shifted PN Codes for CW LIDAR, RADAR, and SONAR - A continuous wave Light Detection and Ranging (CW LiDAR) system utilizes two or more laser frequencies and time or range shifted pseudorandom noise (PN) codes to discriminate between the laser frequencies. The performance of these codes can be improved by subtracting out the bias before processing. The CW LiDAR system may be mounted to an artificial satellite orbiting the earth, and the relative strength of the return signal for each frequency can be utilized to determine the concentration of selected gases or other substances in the atmosphere. | 12-29-2011 |
20120013888 | ELECTRO-OPTICAL DISTANCE METER - [Problem] To provide an electro-optical distance meter in which the measurement time is reduced, and a temperature phase drift of electrical components is reduced. | 01-19-2012 |
20120033197 | DISTANCE MEASURING DEVICE - A distance measuring device measures a distance from a phase difference of beaten down processing signals even when fluctuations occur in a frequency of an oscillator. The distance measuring device includes a laser unit, a dividing device, a reference light receiving unit, and a measuring light receiving unit. The distance measuring device further includes an oscillator, a first mixer, a second mixer, a fourth filter, a fifth filter, a third mixer, a sixth filter, a second filter, a phase difference measuring unit, and a distance measuring unit. The phase difference measuring unit measures a phase difference of the two beat signals extracted by the sixth filter and the second filter. The distance measuring unit measures a distance based on the phase difference measured by the phase difference measuring unit. | 02-09-2012 |
20120038904 | UNIT PIXEL, PHOTO-DETECTION DEVICE AND METHOD OF MEASURING A DISTANCE USING THE SAME - A unit pixel included in a photo-detection device, the unit pixel including a floating diffusion region in a semiconductor substrate, a ring-shaped collection gate over the semiconductor substrate, a ring-shaped drain gate over the semiconductor substrate, and a drain region in the semiconductor substrate, wherein the collection gate and the drain gate are respectively arranged between the floating diffusion region and the drain region. | 02-16-2012 |
20120162633 | SYSTEMS AND METHODS FOR DETERMINING POSITION USING LIGHT SOURCES - A positioning system and method for determining a coordinate of an object may comprise a positioning transmitter system and a positioning receiver system. The positioning transmitter system includes at least four light sources and a master anchor to modulate the light sources to emit modulated light signals each having a modulation frequency. The positioning receiver system comprises a lens to focus the light signals onto an optical sensor, an envelope detector to receive a signal from the optical sensors and provide output signals corresponding to the modulation frequency, and positioning detection circuitry. The positioning detection circuitry receives calibration data; determines at least four phase difference of arrival (PDOA) pairs based on the output signals from the envelope detector; determines at least four phase corrected PDOA pairs based on the calibration data and the PDOA pairs; determines at least four linear distance differences based on the phase corrected PDOA pairs; and determines the coordinate of the object based on the linear distance differences and the calibration data. | 06-28-2012 |
20130044311 | THREE-DIMENSIONAL TOMOGRAPHIC IMAGING CAMERA - A detection apparatus and method for FMCW LIDAR employ signals whose frequencies are modified so that low-cost and low-speed photodetector arrays, such a can be employed for range detection. The LIDAR is includes a single mode swept frequency laser (SFL), whose optical frequency is varied with time, as a result of which, a target beam reflected back by the target is shifted in frequency from a reference beam by an amount that is proportional to the relative range z to the target. The reflected target beam is combined with the reference beam and detected by the photodetector array. The difference between the frequencies of the reflected target beam and the reference beam is reduced to a level that is within the bandwidth of the photodetector array by first modulating the target and/or reference beam. | 02-21-2013 |
20130148103 | RANGE-RESOLVED VIBRATION USING LARGE TIME-BANDWIDTH PRODUCT LADAR WAVEFORMS - In one aspect, a method includes forming range bins from range compressed data, the range compressed data comprising a train of coherent pulses formed based on a transmitted signal from a laser detection and ranging (LADAR) sensor and having a large time-bandwidth product and for each range bin, compensating for motion of the LADAR sensor, performing a Fourier transform on the compressed range data, determining a centroid of individual velocity measurements and performing Fourier transform of the centroid to determine a vibration. | 06-13-2013 |
20140104593 | THREE-DIMENSIONAL TOMOGRAPHIC IMAGING CAMERA BASED ON COMPRESSIVE SENSING - A detection apparatus and method for FMCW LIDAR employ signals that are modified so that low-cost and low-speed photodetector arrays, such as CCD or CMOS cameras, can be employed for range detection. The LIDAR is designed to measure the range to one or more targets and includes a single mode swept frequency laser (SFL), whose optical frequency is varied with time, as a result of which, a target beam which is reflected back by the one or more targets is shifted in frequency from a reference beam by an amount that is proportional to the relative range to the one or more targets. The reflected target beam(s) is/are combined with the reference beam and detected by the photodetector array. In the case of a sparse number of targets to be detected, Compressive Sensing (CS) techniques can be employed by a processor to reduce the number of measurements necessary to determine the range of each target. | 04-17-2014 |
20140118718 | Modulated Laser Range Finder and Method - A laser range finder including a laser configured to project a laser beam onto a target object thereby causing a target beam to be reflected from the target object, wherein the laser beam has a frequency, and wherein the frequency is modulated at a known rate, a first beam splitter positioned to split a reference beam from the laser beam, a second beam splitter positioned to receive the target beam and the reference beam, wherein the target beam and the reference beam are coherently combined, the coherently combined beams establishing a difference frequency, and a detector configured to measure the difference frequency. | 05-01-2014 |
20140204363 | LOW DRIFT REFERENCE FOR LASER RADAR - Laser radar systems include a pentaprism configured to scan a measurement beam with respect to a target surface. A focusing optical assembly includes a corner cube that is used to adjust measurement beam focus. Target distance is estimated based on heterodyne frequencies between a return beam and a local oscillator beam. The local oscillator beam is configured to propagate to and from the focusing optical assembly before mixing with the return beam. In some examples, heterodyne frequencies are calibrated with respect to target distance using a Fabry-Perot interferometer having mirrors fixed to a lithium aluminosilicate glass-ceramic tube. | 07-24-2014 |
20140240693 | Ranging Method and System - The invention relates to the topographic technique field, and provides a ranging method and a system, wherein the ranging method comprises the following steps: modulating measured beam, by a modulated signal of which the frequency is continuously changed over time; emitting the modulated measured beam to a measured object; receiving the reflected measured beam and converting the beam into the measured signals; and comparing the frequency of the modulated signal generated when the measured beam is received with the frequency of the measured signals, thus determining the measured distance. | 08-28-2014 |
20150308824 | LIGHT BEAM RECEIVER FOR RECEIVING UNMODULATED AND MODULATED LIGHT BEAMS - The invention relates to a receiving unit for light-based measurements/surveying using an analog-to-digital converter for the clocked analog-to-digital conversion of light detection signals and a clocking means for clocking the analog-to-digital converter. According to the invention, the clocking means has, for receiving modulated light signals, a phase-locked loop having an input for light detection signals modulated according to the light signal modulation and an output for outputting a frequency multiple of the detected modulation frequency for the analog-to-digital converter clocking. | 10-29-2015 |
20150331110 | WIND MEASUREMENT COHERENT LIDAR - A noise spectral differential unit records a noise spectrum in a state without any received signal, and subtracts the noise spectrum from a received signal spectrum. An offset corrector performs offset correction of the signal spectrum obtained by subtracting the noise spectrum by the noise spectral differential unit with respect to the noise level at a frequency separated from the frequency peak position of the received signal by a prescribed value. A frequency shift analyzer executes signal processing of the signal spectrum resulting after the offset correction and measures a frequency shift. A wind velocity converter makes wind velocity detection from the frequency shift measured by the frequency shift analyzer. | 11-19-2015 |
20150355316 | OPTICAL PULSE CONTRAST IMPROVEMENT USING NONLINEAR CONVERSION - A laser radar (LADAR) system includes a laser transmitter configured to emit laser pulses at a first wavelength, a non-linear converter configured to convert the laser pulses to a second wavelength prior to spectral filtering of amplified spontaneous emission (ASE) that is emitted from the laser transmitter in a spectrum concentrated around the first wavelength, and a spectral filter configured to substantially filter the ASE and allow the laser pulses at the second wavelength to pass. | 12-10-2015 |
20160011312 | FREQUENCY AGILE LADAR | 01-14-2016 |
20160170024 | LASER TRACKER | 06-16-2016 |
20160377721 | BEAT SIGNAL BANDWIDTH COMPRESSION METHOD, APPARATUS, AND APPLICATIONS - High-resolution laser range finding using frequency-modulated pulse compression techniques can be accomplished using inexpensive semiconductor laser diodes. Modern applications of laser range finding often seek to maximize the distance over which they can resolve range together with the range resolution and to minimize the pulse duration in order to acquire more data in less time. The combination of these requirements results in increasing bandwidth requirements for processing the ranging data, which can exceed 10 GHz over ranges of tens of meters, depending on the range resolution and pulse duration. Here we describe a method of compressing this range data bandwidth in real time using low-cost components and simple techniques that require no increase in processing time or resources. | 12-29-2016 |
20160377722 | PORTABLE PANORAMIC LASER MAPPING AND/OR PROJECTION SYSTEM - Techniques are described herein that are capable of forming a depth map and/or projecting an image onto object(s) based on the depth map. A depth map is a three-dimensional representation of an environment. Forming the depth map may utilize a progressive resolution refinement technique. For example, locating information may be determined in accordance with the progressive resolution refinement technique in response to performing a scan of a current point over a field of view. The current point is a point, selected from a plurality of points (e.g., a grid of points) in the field of view, to which a detection beam of light is directed at a respective time as the scan is performed over the field of view. In accordance with this example, the locating information may be coordinated with the scan to form the depth map. | 12-29-2016 |
20190146070 | Scanning LiDAR System and Method with Spatial Filtering for Reduction of Ambient Light | 05-16-2019 |
20190146074 | LASER DETECTION AND RANGING DEVICE FOR DETECTING AN OBJECT UNDER A WATER SURFACE | 05-16-2019 |
20220137216 | TECHNIQUES FOR RANGE AND VELOCITY MEASUREMENTS IN A NON-DEGENERATE LIDAR SYSTEM - A light detection and ranging (LIDAR) system is provided that includes a first optical source and a second optical source configured to emit respectively a first optical beam and a second optical beam that are nondegenerate and are chirped antiphase and at least one tap configured to split each of the first optical beam and the second optical beam to generate a first local oscillator and a second local oscillator. The LIDAR system further includes lensing optics to direct the first and second optical beams toward a target and collect reflected light from the first optical beam and second optical beam incident upon the target into a return path, the reflected light being collected into a return optical beam comprising a first return signal and a second return signal, and a first optical detector and a second optical detector configured to detect a first beat frequency generated from by mixing the first return signal with the first local oscillator and a second beat frequency generated from mixing the second return signal with the second local oscillator. | 05-05-2022 |