Abstract: The present invention relates to a light detecting and ranging (LiDAR) device for obtaining information on a distance from an object using laser light.

Abstract: In accordance with some embodiments of the present disclosure, an inspection method of a photomask includes performing a first inspection process, unloading the photomask from the inspection system, and performing a second inspection process. In the first inspection process, a common Z calibration map of an objective lens of an optical module with respect to the photomask is generated and stored, and a first image of the photomask is captured by using an image sensor while focusing the objective lens of the optical module based on the common Z calibration map. The photomask is unloaded from the inspection system. In the second inspection process, the photomask is loaded on the inspection system and a second image of the photomask is captured by using an image sensor while focusing an objective lens of an optical module based on the common Z calibration map generated in the first inspection process.

Abstract: An integrated technological platform enabling real-time quantitative multiparameter metabolic profiling, utilizing either or both of extra and intracellular optical sensors, individually or simultaneously. A scalable embedded micropocket array structure, generally fabricated on fused silica substrates, facilitates the integration of multiple, spatially separated extracellular sensors for multiparameter analysis in a container formed with the use of an activation mechanism forming part of a device configured to hold the container during the measurements. The creation of hermetically sealed microchambers is carried out with a pneumatically and/or mechanically and/or electromechanically driven device that is “floating” within the holding device and that is optionally equipped with a vacuum/suction mechanism to hold a component of the container at its surface.

Abstract: An aerosol-generating system is provided, including an aerosol-generating article including at least one component incorporating an aerosol-forming substrate; a luminescent material having a temperature-dependent phosphorescence characteristic; a heater configured to heat the luminescent material and the at least one component; and an aerosol-generating device including a support configured to at least partially receive the aerosol-generating article, a light source configured to illuminate and to excite the luminescent material, a detector configured to detect a temperature-dependent phosphorescence characteristic of the excited luminescent material, and electrical hardware configured to control heating by the heater based on the detected characteristic. A method for controlling the aerosol-generating system is also provided.

Abstract: A traffic control system and a method are provided for detecting changes in traffic patterns at an intersection, establishing traffic rules therefore, and communicating the same to objects at the intersection. The method comprises receiving, by a processor, traffic data at an intersection; determining, by the processor, an average path taken by one or more objects at the intersection; determining, by the processor, a deviation of the average path from a historical average path; based on the deviation, determining by the processor, a traffic rule is to be implemented for incoming objects detected; and communicating, by the processor, the traffic rule to the incoming objects.

Abstract: The disclosed embodiments include an apparatus and method of using a laser to scan the ground or a target from an airborne or ground-based platform. In certain embodiments, the apparatus and method produces a 3-D elevation model of the terrain. In some embodiments, the apparatus includes a pulsed laser, a receiver to detect and amplify the pulse after being reflected by objects on the ground (or the ground itself), and electronics which measures the time of flight of the optical pulse from which the slant range to the target is calculated. Technical advantages of the disclosed embodiments include avoiding blind zones to ensure that no laser shots are wasted. In certain embodiments for airborne applications, the apparatus may also be configured to maintain a constant swath width or constant spot spacing independent of aircraft altitude or ground terrain elevation.

Abstract: Measuring equipment for a crimp connection comprises a signal processing unit (150), a ranging sensor arrangement (100) based on using optical radiation, and a moving mechanism (102) that moves a formed crimp connection (104) and the ranging sensor arrangement (100) in relation to each other. The ranging sensor arrangement (100) measures the distance between the ranging sensor arrangement (100) and crimp connection (104) while the ranging sensor arrangement (100) and moving mechanism (102) are moved in relation to each other. The signal processing unit (150) generates surface profile data on the basis of the measured distances, uses the surface profile data of the crimp connection (104) to determine the quality of the crimp connection (104), and displays data related to the crimp connection (104).

Abstract: The invention concerns a method and a device for calibrating at least one scanning system (4, 5, 17) when producing an object (8) by additive manufacturing, wherein the coordinates of one or several reference positions are measured in the relative coordinate system of each scanning system (4, 5, 17), after which the calibration of each of the scanning systems is adapted starting from the measured coordinates of the reference positions.

Abstract: A scanning optical system, includes a mirror unit equipped with a first mirror surface and a second mirror surface each of which inclines to a rotation axis; and a light projecting system which includes at least one light source to emit a light flux toward the first mirror surface. A light flux emitted from the light source is reflected on the first mirror surface of the mirror unit, thereafter, reflected on the second mirror surface, and then, projected so as to scan in a main scanning direction onto an object in accordance with rotation of the mirror unit, and in a case where a direction included in a main scanning plane is set to 0 degree, the light flux reflected on the second mirror surface is polarized in a range within an angle of ±30 degrees to the main scanning plane.

Abstract: A vehicle includes a body with multiple interior and exterior surfaces and a lidar system including a set of one or more sensor units. Each sensor unit includes a light source configured to emit light, a scanner configured to direct the emitted light to scan a field of regard of the sensor unit according to a scan pattern, a receiver configured to detect the light scattered by one or more remote targets, and a housing enclosing the light source, the scanner, and the receiver. The housing of each sensor unit is embedded in one of the interior or exterior surfaces, so that a first portion of the housing projects out of the body and a second portion of the housing is inside the body.

Abstract: An apparatus for testing a circuit includes a source signal input configured to receive a source signal, an evaluation signal input configured to receive an evaluation signal, and a coefficient extractor configured to extract a plurality of coefficients of a preselected polynomial representing the evaluation signal and the source signal. A weight factor storage contains a plurality of weight factors corresponding to frequency filters. An Adjacent Channel Power Ratio (ACPR) calculator is configured to calculate an ACPR value from the evaluation signal and the source signal by applying the plurality of weight factors from the weight factor storage to the plurality of coefficients the plurality of weight factors selected according to a main channel frequency range and an adjacent channel frequency range, and determining whether the ACPR value is within an acceptable range and generating a corresponding indication.

Abstract: Disclosed are methods and systems for inspecting photolithographic reticles. A first and second reticle that were fabricated with a same design are obtained. A first and second reticle image of the first and second reticles are also obtained. The first reticle image is compared to the second reticle image to output a difference image having a plurality of difference events corresponding to candidate defects on either the first or second reticle. An inspection report of the candidate defects is then generated.

Abstract: The present disclosure describes optoelectronic modules with low- and high-power illumination modes for distance measurements and/or multi-dimensional imaging. Various implementations are described that include low- and high-power emitters. In some instances, a low-power mode may be used to monitor a scene where object movement can activate a high-power mode. In such instances, power reduction may be achieved.

Abstract: An optical scanner includes a rotatable polygon mirror and a second mirror. The rotatable polygon mirrors includes a block having a first wall, a second wall, and reflective surfaces extending between the first and second walls, the reflective surfaces being angularly offset from one another along a periphery of the block; a polygon mirror axle extending into the block through at least one of the first and second walls, about which the block rotates; a motor driving rotation of the block; and chamfers in the block, each of the chamfers being bounded by a pair of adjacent reflective surfaces and the second wall. The second mirror is pivotable along an axis orthogonal to the polygon mirror axle and more proximate to the second wall of the block than the first wall of the block.

Abstract: A lidar system includes a light source configured to produce a first and second beams of light, receivers to configured to detect light from the first and second beams of light and scattered by one or more remote targets, and a scanner including a first scan mirror configured to pivot along a first-mirror pivot axis to scan the first beam of light along a first direction, a second scan mirror configured to pivot along a second-mirror pivot axis to scan the second beam of light along the first direction, and a polygon with multiple reflective surfaces configured to rotate about a polygon-mirror rotation axis to scan the first and second beams of light along a second direction.

Abstract: A lidar system includes one or more light sources configured to generate a first and second beams of light, a scanner configured to synchronously scan a field of regard of the lidar system using the two beams, and a receiver configured to detect light of the two beams scattered by one or more remote targets. The scanner includes a rotatable polygon mirror having a block having a first wall, a second wall, and reflective surfaces extending between the first and second walls, the reflective surfaces being angularly offset from one another along a periphery of the block; a polygon mirror axle extending into the block, about which the block rotates; optical elements configured to direct the first and second beams of light respectively to two adjacent reflective surfaces of the rotatable polygon mirror; and a second mirror pivotable along an axis orthogonal to the polygon mirror axle.

Abstract: The present invention provides a detecting device and a detecting method thereof. The detecting device serves to detect defects on the display substrate and comprises: a detecting unit for searching for defects on the display substrate and taking pictures of areas in which the defects are located; and a control unit for comparing and analyzing the pictures sent from the detecting unit to assist the detecting unit to search for the defects on the display substrate, and classifying and counting the pictures of areas in which the defects are located. The detecting device can automatically search for and analyze defects on the display substrate, thereby time for analyzing defects on the display substrate is reduced, and defect analyzing efficiency is improved.

Abstract: To detect return light pulses in a lidar system when scanning in the forward-scanning and reverse-scanning directions, a light source may transmit first light pulses having a first wavelength when scanning in the forward-scanning direction and may transmit second light pulses having a second wavelength when scanning in the reverse-scanning direction. A diffractive optical element (DOE) is configured to deflect the two wavelengths in opposite directions, so that light pulses are transmitted ahead of the field of view of the detector in the scanning direction of the lidar system. A controller may determine the scanning direction of a scanner in the lidar system and transmit a control signal to a light source indicative of a wavelength that corresponds to the scanning direction. The light source may then transmit light pulses at the requested wavelength.

Abstract: The present invention relates to a bending assembly for bending a workpiece. The assembly includes a bending apparatus configured to bend the workpiece and form a curved portion of the workpiece. The curved portion of the workpiece has a longitudinal periphery and a curvature. The assembly includes a camera configured to produce an image of the longitudinal periphery of the curved portion of the workpiece. The assembly includes a processor configured to receive the image of the longitudinal periphery of the curved portion of the workpiece. The processor is configured to identify a plurality of measuring points spaced-apart along the longitudinal periphery of the curved portion of the workpiece. The processor is configured to determine the curvature of the curved portion of the workpiece based on the measuring points.

Abstract: A method for detecting a vehicle comprising: providing a multi-channel scannerless full-waveform lidar system operating in pulsed Time-Of-Flight operation oriented towards a surface of the roadway to cover the detection zone; providing at least one initialization parameter; emitting pulses at an emission frequency; receiving reflections of the pulses from the detection zone; and acquiring and digitalizing a series of individual complete traces at each channel of system; identifying at least one detection in at least one of the traces; obtaining a height and an intensity for the detection; determining a nature of the detection to be one of an environmental particle detection, a candidate object detection and a roadway surface detection; if the nature of the detection is the candidate object detection, detecting a presence of a vehicle in the detection zone.

Abstract: A system for locating at least one surface feature, such as a cooling aperture, on a turbine component is provided. The system includes at least one feature marker configured for placement adjacent to the at least one surface feature. The system also includes at least one sensor configured for non-visual detection of the at least one feature marker. The system also includes a control device coupled to the at least one sensor for receiving signals from the at least one sensor, wherein the signals represent data indicative of one of a presence of the at least one feature marker and an absence of the at least one feature marker.

Abstract: A three-dimensional object detection device is provided with an image capturing device, a three-dimensional object detection unit, a rainfall state detection unit, a three-dimensional object assessment unit and a controller. The image capturing device captures an area rearward of a vehicle. The three-dimensional object detection unit detects a three-dimensional object rearward of the vehicle and calculating a traveling speed of the three-dimensional object, based on images obtained by the image capturing device. The rainfall state detection unit detects a state of rainfall including cases of rainfall or formation of a water film on a road surface due to rainfall. The three-dimensional object assessment unit accesses the three-dimensional object to be another vehicle when the traveling speed of the detected three-dimensional object lies within a preset setting range. The controller changes the traveling speed setting range to be narrower when the rainfall state detection unit has detected a rainfall state.

Abstract: A method for tracking and characterizing a plurality of vehicles simultaneously in a traffic control environment, comprising: providing a 3D optical emitter; providing a 3D optical receiver with a wide and deep field of view; driving the 3D optical emitter into emitting short light pulses; receiving a reflection/backscatter of the emitted light, thereby acquiring an individual digital full-waveform LIDAR trace for each detection channel of the 3D optical receiver; using the individual digital full-waveform LIDAR trace and the emitted light waveform, detecting a presence of a plurality of vehicles, a position of at least part of each vehicle and a time at which the position is detected; assigning a unique identifier to each vehicle; repeating the steps of driving, receiving, acquiring and detecting, at a predetermined frequency; tracking and recording an updated position of each vehicle and an updated time at which the updated position is detected.

Abstract: A method includes generating, using a data processor, information showing variations of a parameter across a photo mask relative to an average value of the parameter measured at various locations on the photo mask. For example, the information can include data points, and each data point can be determined based on a ratio between a measurement value and an average of a plurality of measurement values.

Abstract: A testing box for testing light sources, the testing box comprising: an enclosure comprising an opening for receiving a light source; a sensor of a light property for light emitted inside the enclosure; and a comparator of the light property sensed by the sensor and a shifted test box boundary for the light property, wherein the shifted test box boundary is based on a correlation between a measured light property of a test light source in an integrating sphere and a measured light property of the test light source in the testing box.

Abstract: A system for determining the speed and position of objects comprises a beam source, a transmit reflection device, a beam receiver, a receive reflection device, and a controller. The beam source may generate a beam. The transmit reflection device may reflect the beam at the objects and may include a plurality of transmit faces with each transmit face oriented at a different angle and operable to reflect the beam at a different height. The beam receiver may detect the beam. The receive reflection device may include a plurality of receive faces with each receive face oriented at a different angle and operable to focus the beam reflected from objects at different heights onto the beam receiver. The controller may determine the position of the objects over time and calculate the speed of the objects based on a change in the position of the objects.

Abstract: A video calibration device comprising an elongated image tube having a length, a first opening at one end of the image tube and a second opening at the opposite end of the image tube. The device includes an elongated sensor tube having a length, a first opening at one end of the sensor tube and a second opening at the opposite end of the sensor tube. The first opening of the sensor tube is adapted to support a video calibration sensor. A video calibration sensor is disposed in the first opening of the sensor tube. The sensor tube is sealingly secured to the image tube at an angle whereby the second opening of the sensor tube and the second opening of the image tube are substantially juxtaposed.

Abstract: The invention relates to a method and device for optically measuring external thread profiles, particularly at the ends of pipes, wherein the thread is previously synchronously produced in a production line and is continuously measured in line from start to finish of the thread prior to further processing. The aim of the invention is to allow cost-effective inspection of the thread during synchronous production of the thread.

Abstract: A scanning optical device includes a rotating polygonal mirror having a plurality of reflecting faces. A first light source emits a first light beam from one section obtained by sectioning the scanning optical device with a plane passing through the rotation axis of the rotating polygonal mirror. A second light source emits a second light beam from the other section. The first calculation unit calculates scan time of the first light source. The second calculation unit calculates scan time of the second light source. The jitter correction unit corrects jitter by controlling a pixel clock supplied to the first light source according to the scan time of the second light source. The jitter correction unit also corrects jitter by controlling a pixel clock supplied to the second light source according to the scan time of the first light source.

Abstract: A method of measuring a length of sections of extrados or intrados curves of an elongated workpiece travelling in a bending machine along a forwarding direction, the elongated workpiece having cross-sections each of which is separated by a neutral axis in both an extended portion and a compressed portion when the elongated workpiece is subjected to bending, and at least a neutral cross-section, i.e. not subjected to bending, neutral cross-section beyond which the bending of the elongated workpiece begins along the forwarding direction thereof, provides a measuring instrument positioned so that it engages either an extrados or an intrados point of the elongated workpiece near the neutral cross-section, but displaced therefrom in the forwarding direction of the elongated workpiece. Further, a measuring instrument on a bending machine that embodies the method is described.

Abstract: A navigation system for easily determining defective positions is provided. In the case of CAD navigation to defective positions, logical information for indicating defective positions is created in a CAD format, instead of CAD data of physical information indicating circuit design. Specifically, by attaching marks such as rectangles, characters, or lines, to an electron microscope image with software, quick navigation is performed with required minimum information. By using created CAD data, re-navigation with the same equipment and CAD navigation to heterogeneous equipment are performed.

Abstract: A laser irradiation process includes: scanning a substrate with laser having a predetermined lasing frequency at different irradiation intensities to form a plurality of first irradiation areas corresponding to the irradiation intensities; illuminating the first irradiation areas to reflected light receive from the first irradiation areas; determining microcrystallization intensity based on the received reflected light; and determining irradiation intensity based on the thus determined microcrystallization intensity. The laser irradiation process uses the irradiation intensity for irradiating a polycrystalline film in a product semiconductor device.

Abstract: Myocardial tissue tracking techniques are used to project or guide a single manually-defined set of myocardial contours through time. Displacement encoding with stimulated echoes (DENSE), harmonic phase (HARP) and speckle tracking is used to encode tissue displacement into the phase of complex MRI images, providing a time series of these images, and facilitating the non-invasive study of myocardial kinematics. Epicardial and endocardial contours need to be defined at each frame on cine DENSE images for the quantification of regional displacement and strain as a function of time. The disclosed method presents a novel and effective two dimensional semi-automated segmentation technique that uses the encoded motion to project a manually defined region of interest through time. Contours can then easily be extracted for each cardiac phase.

Abstract: A motion control apparatus for measuring and scanning an object. The motion control apparatus includes a base. The motion control apparatus also includes an object support assembly that is coupled to the base. The object support assembly receives the object to be scanned and measured. The motion control apparatus includes a scanner track that extends above from the base. The scanner and object are moveable about multiple axes to position to the scanner with respect to the object for viewing the object by the scanner for obtaining measurements of the object.

Abstract: A laser irradiation process includes: scanning a substrate with laser having a predetermined lasing frequency at different irradiation intensities to form a plurality of first irradiation areas corresponding to the irradiation intensities; illuminating the first irradiation areas to reflected light receive from the fist irradiation areas; determining microcrystallization intensity based on the received reflected light; and determining irradiation intensity based on the thus determined microcrystallization intensity. The laser irradiation process uses the irradiation intensity for irradiating a polycrystalline film in a product semiconductor device.

Abstract: A navigation system for easily determining defective positions is provided. In the case of CAD navigation to defective positions, logical information for indicating defective positions is created in a CAD format, instead of CAD data of physical information indicating circuit design. Specifically, by attaching marks such as rectangles, characters, or lines, to an electron microscope image with software, quick navigation is performed with required minimum information. By using created CAD data, re-navigation with the same equipment and CAD navigation to heterogeneous equipment are performed.

Abstract: Apparatus and techniques for automated optical inspection (AOI) utilizing image scanning modules with multiple objectives for each camera are provided. A scanning mechanism includes optical components to sequentially steer optical signals from each of the multiple objectives to the corresponding camera.

Abstract: A method of measuring a coating thickness involves projecting a pattern of light on a surface. A first reflection of the pattern of light is received by a first image capturing device. A second reflection of the pattern of light is received by an image capturing device which may be the same or a different image capturing device. The first reflection is compared with the second reflection. A first dated map of the surface is created by comparing the first reflection and the second reflection. A coating is deposited on the surface. A second data map of the surface with the coating is created by comparing reflections. The first data map and the second data map are then compared to determine a thickness of the coating.

Abstract: A method of measuring a position of a surface of an object while the object is scanned relative to a detection unit in a scanning direction in an X-Y plane. The detection unit is configured to detect the position of the surface in a Z direction perpendicular to the X-Y plane.

Abstract: A method and apparatus for inspecting the surface of articles, such as chips and wafers, for defects, includes a first phase of optically examining the complete surface of the article inspected at a relatively high speed and with a relatively low spatial resolution, and a second phase of optically examining with a relatively high spatial resolution only the suspected locations for the presence or absence of a defect therein.

Abstract: In a method of inspecting defects, a first actual region of an actual object is inspected based on a first characteristic parameter as an inspection condition. A point where an inspection region of the actual object is changed into a second actual region from the first actual region is determined. The second actual region is then inspected based on a second characteristic parameter as the inspection condition. The first and second parameters may include contrast of a light that is reflected from a reference object, intensity of the light, brightness of the light, a size of a minute structure on the reference object, etc. The characteristic parameters of each reference region on the reference object are set. Thus, the defects may be accurately classified so that a time and a cost for reviewing the defects may be markedly reduced.

Abstract: A method and system are provided for inspecting manufactured parts such as cartridges and cartridge cases and sorting the inspected parts. The system includes an illumination assembly for evenly illuminating a plurality of annular, exterior side surfaces of a part when the part is located in a circumference vision station with rings of strobed radiation to generate corresponding reflected radiation signals. A plurality of imaging detectors in the form of CCD cameras are located at the vision station to generate a plurality of side images. The system further includes at least one side image processor for processing the side images of each part to identify parts having an unacceptable defect. The system further includes a mechanism for directing parts identified as having an unacceptable defect to a defective part area and directing parts not identified as having an unacceptable defect to an acceptable part area.

Abstract: An automated optical inspection system, comprising at least one camera having a field of view; and at least one image scanning module comprising a plurality of objective modules arranged to have fields of view covering a portion of an article during inspection, and an image selection mirror mechanism, such as a pentaprism movable to sequentially select and transfer images of the fields of view from the objective modules to the at least one camera, and a beam splitter operative to simultaneously direct illumination from at least one illumination source to a portion of the article and to direct an image of the portion of the article to at least one camera, wherein the beam splitter is operative to pivot about at least one axis, thereby to create motion of the image of the article within the field of view of the camera. The objective modules may be arranged in a pair of back-to-back arcs each served by and partially encircling its own optical head.

Abstract: Apparatus and techniques for automated optical inspection (AOI) utilizing image scanning modules with multiple objectives for each camera are provided. A scanning mechanism includes optical components to sequentially steer optical signals from each of the multiple objectives to the corresponding camera.

Abstract: The invention relates to an optoelectronic detection device, especially a laser scanner, comprising a transmitting device for transmitting preferably pulsed electromagnetic radiation, also comprising at least one receiving device which is associated with the transmitting device and at least one deflection device which is used to guide radiation which is transmitted by the transmitting device into a monitoring area and radiation which is reflected by the monitoring area to the receiving device. The transmitting device comprises several, preferably two, separate transmitting modules which respectively transmit radiation along a specific transmission path.

Abstract: A method and system for maximizing process capability in a progressive forming operation. The method compensates for deviations introduced by unformed components, and uses closed loop feedback to compensate for deviations introduced by forming tools. Fiducial features are detected on an incoming component, and a first compensation value is calculated from displacement of the fiducial features from an ideal forming location on the component. Component position with respect to a theoretical forming position is adjusted according to the first compensation value. Placement of a feature formed on the component at the adjusted position is detected and compared to the ideal forming location to obtain a difference value. A second compensation value is derived from a plurality of difference values. Forming positions for subsequent incoming components are adjusted with respect to the theoretical forming position according to first and second compensation values.

Abstract: Systems and methods for identifying an interchangeable lens in a vision system having a controllable light source, a camera, and the lens to be identified. Light provided by the light source is transferred to the camera by the lens to be identified. The amount of light transferred to the camera for a particular reference configuration of the vision system depends distinguishably on the characteristics of the lens to be identified. A camera output is measured for a desired light source setting and the desired light source setting and associated measured camera output are compared with stored lens identification calibration data. The stored lens identification calibration data is obtained by measuring the camera output for a plurality of lenses using a plurality of light source settings. In various exemplary embodiments, the light transferred from the light source to the camera is reflected and/or backscattered light from the lens to be identified.

Abstract: A system for optical detection of kinetic samples. The system includes a dual set of detectors linked to a single processor. The time of signal integration is different for each detector, allowing one detector to have a higher sensitivity by integrating over a longer time period while the second detector using shorter integration periods is able to measure kinetic events.

Abstract: The invention is directed to an ultrasonic testing system. The system tests a manufactured part for various physical attributes, including specific flaws, defects, or composition of materials. The part can be housed in a gantry system that holds the part stable. An energy generator illuminates the part with energy and the part emanates energy from that illumination. Based on the emanations from the part, the system can determined precisely where the part is in free space. The energy illumination device and the receptor have a predetermined relationship in free space. This means the location of the illumination mechanism and the reception mechanism is known. Additionally, the coordinates of the actual testing device also have a predetermined relationship to the illumination device, the reception device, or both.

Abstract: A method for tracking and characterizing a plurality of vehicles simultaneously in a traffic control environment, comprising: providing a 3D optical emitter; providing a 3D optical receiver with a wide and deep field of view; driving the 3D optical emitter into emitting short light pulses; receiving a reflection/backscatter of the emitted light, thereby acquiring an individual digital full-waveform LIDAR trace for each detection channel of the 3D optical receiver; using the individual digital full-waveform LIDAR trace and the emitted light waveform, detecting a presence of a plurality of vehicles, a position of at least part of each vehicle and a time at which the position is detected; assigning a unique identifier to each vehicle; repeating the steps of driving, receiving, acquiring and detecting, at a predetermined frequency; tracking and recording an updated position of each vehicle and an updated time at which the updated position is detected.