294 results about "Radar calibration" patented technology

Methods and articles of manufacture for estimating or deriving weather observations/conditions for any given location using observed weather conditions from neighboring locations, radar data, lightning data, satellite imagery, etc. An initial estimate of weather conditions for a location is made based on a downscaling process using the current conditions the neighboring locations. A measure of corroboration between the radar data and surface weather conditions at official observing stations may be established. Through the results of the downscaling process, radar calibration statistics and estimates of ground-based precipitation, the corroboration can be iteratively tuned, resulting in a weather conditions vector containing associated meteorological fields for locations that lie between or near the sparse network of official observing sites from which an estimate of the weather conditions may be made.

A laser-radar calibration method and a device thereof are disclosed. The method comprises the step of external parameter calibration, wherein the external parameter calibration includes steps that a radar moves along with a vehicle; radar reflection data is collected; the collected data is substituted into a lattice cloud energy equation and an energy equation value is a minimum external calibration parameter through solving. Compared to the prior art, by using the above technical scheme, data returned by the laser radar in real time can be analyzed; a parameter of the laser radar itself can be initiatively corrected so that effects of rapidly correcting the laser radar, increasing scanning data accuracy and increasing a scanning image differentiation degree are reached.

Methods and articles of manufacture for estimating or deriving weather observations for any given location. Using weather radar data, a correspondence between the weather radar coverage, intensity and the precipitation type may be monitored. From that, a measure of corroboration between the radar data and surface weather conditions may be established. Through radar calibration statistics and estimates of ground-based precipitation, the corroboration can be iteratively tuned, resulting in a final improved estimate of the present weather and associated meteorological fields. The associated meteorological fields may include at least one of a probability of precipitation, precipitation accumulation, precipitation rate, and horizontal visibility.

The invention relates to a multi-line laser radar calibration method. The multi-line laser radar calibration method comprises the following steps that two parameters are calibrated by decoupling alpha, beta, delta <z> and gamma, delta <x>, delta <y> respectively; parameters alpha, beta and delta <z> are calibrated by extracting horizontal ground features; and the constraint equations are constructed by rotation matrix v<R> and the translation matrix v<T> provided by GPS, and calibration parameters gamma, delta <x> and delta <y> are solved. According to the multi-line laser radar calibration method, manual measurement of calibration parameters is not required, special calibrated objects are not required, operation is convenient, and calibration efficiency is high. Calibration accuracy can be improved by using flatland features and high precision GPS information.

A wind turbine (1) is provided, having a wind turbine tower (2) and at least one rotatable blade (5), and further comprising a system for measuring rotor blade vibration of said wind turbine. The system comprises at least one Doppler radar unit (7) operatively configured to emit and receive radar signals, the radar unit being mounted on the wind turbine tower at a position above the lowest position of the at least one blade, the radar unit being positioned so as to measure reflections of an emitted radar signal from the turbine blade. A processing unit is configured to receive measurement data from the radar unit and to determine, by analysis of Doppler shift in received radar signals relative to transmitted signals due to movement of the blade towards or away from the turbine tower, the velocity of the blade in the direction towards or away from the turbine tower. Using a radar unit to measure blade velocity allows a determination to be made of the vibrations occurring in the blade without needing an internal sensor in the blade. This reduces manufacturing and maintenance costs of the blades since sensors in the blades will not need to be replaced, and sensors positioned on the tower are easier to replace in the field.

The invention provides a laser radar calibration system and method, and belongs to the technical field of laser radar systems. The laser radar calibration system comprises a reflecting mechanism for receiving and reflecting a laser beam, and a control unit which is in a communication connection with a laser radar, wherein multiple reflecting points exist on the reflecting mechanism; and the distances between the reflecting points and the laser radar vary continuously. The laser radar calibration method comprises the following steps: emitting the laser beam in a preset measuring angle directionby the laser radar; making the laser beam irradiate on the reflecting mechanism with distances away from the laser radar vary continuously; acquiring the errors between measured distances and actualdistance; and determining calibration data according to the errors and the actual distances. According to the laser radar calibration system and method provided by the invention, the automation of thecalibration process is realized through arrangement of the reflecting mechanism with distances away from the laser radar vary continuously. Moreover, measurement data varying continuously can be acquired without moving the position of the reflecting mechanism, thereby effectively improving the calibration efficiency and the calibration accuracy.

The invented Rayleigh windfinding laser radar calibration method uses acoustooptic frequency shift and laser spectrum Doppler broadening principle as basis, and utilizes two acoustooptic frequency shifters whose frequency can be regulated, and makes them be series-connected to implement laser frequency zero-crossed wideband continuous regulation, and utilizes Doppler stretcher to stretch spectrum so as to make accurate and quick calibration of Rayleigh windfinding radar.

The system and method for radar calibration using antenna leakage is a simplified means of calibrating the channels in amplitude and phase using natural signal leakage between antennas. It utilizes as calibration signal a wideband sinusoidal Frequency Modulated Continuous Wave (FMCW) waveform with a modulation index and modulation frequency chosen to generate spectral components (or discrete signal frequencies) that fall within the receiver Doppler passband of the radar. The calibration signal is radiated out of the transmitting antenna and enters the radar receiver front-end through the transmit-to-receive antenna leakage which occurs naturally. This technique provides a low-complexity (simpler hardware realization) means for achieving a wideband calibration rapidly and is a practical alternative to the conventional calibration approach that relies on generating offset Doppler signals that are coupled into the radar receiver front-end through the use of couplers and cabling within the radar.

The invention relates to an ROS-based laser radar and camera fusion calibration system and calibration method, and the system comprises: a radar calibration module which is used for obtaining the external parameters of a laser radar, i.e., the conversion relation from a radar coordinate system of the laser radar to a world coordinate system; a camera calibration module which is used for acquiringinternal parameters of the camera; a fusion calibration module which is used for receiving the external parameters of the laser radar and the internal parameters of the camera and solving the externalparameters of the camera, namely solving a transformation relation from a world coordinate system to a camera coordinate system. Data transmission among the radar calibration module, the camera calibration module and the fusion calibration module is realized based on an ROS platform. the radar calibration module comprises a laser radar, a pile barrel and two calibration plates, and the camera calibration module comprises a camera and a calibration plate. According to the space synchronization method for realizing data fusion of the laser radar and the camera, the defects of insufficient sensing dimension, lack of information and the like existing in the conventional single sensor sensing are overcome.

A radar system with an array antenna includes various signal paths, including beamformers, extending between an exciter, a receiver, and the array antenna. The signal paths are calibrated by a method that includes frequency modulation of the exciter signals that reach the “antenna” and additional amplitude modulation of signals just as they enter the receiver. Leakage paths directly from the exciter to the receiver are unmodulated, those extending from the exciter through the beamformer are amplitude modulated, and only those reaching the “antenna” and returning to the receiver are both amplitude and frequency modulated. The receiver is tuned to receive only the “doubly-modulated” signals, which tends to reject leakage signals.

The embodiment of the invention provides a vehicle-mounted three-dimensional laser radar calibration method and system. The calibration method does not depend on special facilities, uses the road surface as a reference plane, and solves external calibration parameters of one or more three-dimensional laser radars relative to a vehicle body coordinate system by using the characteristics of the natural environment, thereby being capable of greatly improving the accuracy of the calibration parameters, and providing a basis for data fusion processing of a multi-mode sensor. The vehicle-mounted three-dimensional laser radar system comprises a main laser radar installed on the top of the vehicle and zero to multiple auxiliary laser radars installed on other parts of the vehicle.

A Radar Calibration Processor (“RCP”) for calibrating the amplitude of a stepped-chirp signal utilized by a synthetic aperture radar (“SAR”) is disclosed. The RCP includes a periodic amplitude error (“PAE”) calibrator, first non-periodic amplitude error (“NPAE”) calibrator in signal communication with the PAE calibrator, and a second NPAE calibrator in signal communication with the first NPAE calibrator.

The invention discloses a remote laser radar calibration system. The calibration is carried out between a laser radar and a calibration device, and the calibration device is provided with a support, acalibration panel, and an adjustment device. The calibration panel is disposed on the support, and the adjustment device is used for adjusting the height and angle of the calibration panel. The adjustment device comprises a support which is provided with an upper part and a lower part, wherein the upper part is provided with a plurality of adjustment holes at different heights, and the lower partand a folding device are fixed through a connecting device. The adjustment device also comprises an inner rotating control device and an outer rotating control device, wherein the outer rotating control device is disposed between the inner rotating control device and the support, and the inner and outer rotating control devices have the same center. The scale position is read through the mutual rotation of the inner and outer rotating control devices, and the angle is adjusted. In addition, a fixed device can pass through the calibration panel, is disposed on the adjustment holes of the support in a bulged manner, and is fixed on the adjustment holes through a spiral fixing part.

The invention discloses a rotatable double-antenna PARC (polarimetric active radar calibrator) and a polarimetric active radar calibration method thereof. According to the PARC, polarization filters are additionally mounted at apertures of a receiving antenna and a transmitting antenna; the rotatable double-antenna design is adopted, and different posture combinations of the receiving antenna and the transmitting antenna can form different polarization combinations. Each antenna of the designed rotatable double-antenna PARC can rotate independently, the receiving antenna and the transmitting antenna of the PARC are controlled to be combined in different polarization manners, and multiple forms of polarimetric scattering matrixes of the PARC can be obtained. During mounting of the PARC, the delay parameter is adjusted, and a rotating mechanism is controlled, and the PARC rotates at constant and slow speeds, and any to-be-calibrated objects can be calibrated. The polarization filters are additionally mounted at the apertures of the antennas, so that the polarimetric isolation of each of the receiving antenna and the transmitting antenna can be greatly increased, and the polarimetric calibration accuracy is improved.

A Radar Calibration Processor (“RCP”) for calibrating the phase of a stepped-chirp signal utilized by a synthetic aperture radar (“SAR”) is disclosed. The RCP includes a periodic phase error (“PPE”) calibrator, first non-periodic phase error (“NPPE”) calibrator in signal communication with the PPE calibrator, and a second NPPE calibrator in signal communication with the first NPPE calibrator.

The invention discloses an ADS-B (automatic dependent surveillance broadcast) and radar combined system error estimation method, which belongs to the technical field of ADS and radar information fusion. At present, when the ADS-B equipment is used for radar calibration, the existing serious problem is that the time when the ADS-B emission equipment emits data information cannot be obtained, and no time alignment exists for the radar measuring data and the ADS-B data, so that the following error calibration is inaccurate, while all the conventional algorithms evade the problem. Aiming to effectively solve the problems of time alignment and error estimation of the radar system in the practical application, the method provided by the invention has the following steps of defining a novel ADS-B time system error based on the receiving time of the ADS-B, building the ADS-B and radar system error combined estimation model, and finally solving through the Least Squares algorithm, so that the radar can be accurately calibrated through the ADS-B.

Array antenna calibration verification coupling interrogator and responder with mode-related interrogation signal having a previous calibration phase angle, producing in responder a characteristic interrogation response. Conjugate signal is generated by reversing phase of interrogation signal, producing in responder a characteristic conjugate response. Interrogation and conjugate responses sensed and combined to determine difference characteristic for responder array element. Responder difference characteristic iteratively determined for elements in antenna array representative of present calibration verification state. Present and previous calibration verification states compared, with significant variation adapting array to desired calibration verification state. Verification processor controls interrogator, responders, and signals providing built-in missile RADAR calibration verification.

The invention provides a laser radar calibration device and method, and belongs to the technical field of a laser radar system. The laser radar calibration device comprises reflection units, adjustment mechanisms and a control unit, the distances between the reflection units and a laser radar change continuously, the adjustment mechanisms are used to adjust the included angles between the reflection units and a laser beam respectively, and the control unit is in communication connection with the laser radar. In the calibration method, the laser radar emits the laser beam according to a presentmeasurement angle direction, and the laser beam irradiates the reflection units; and the included angles between the reflection units and the laser beam are adjusted, an error of a measurement distance relative to the practical distance is obtained, and calibration data of the laser radar is determined according to the error, the intensity of a laser signal and the practical distance. According to the laser radar calibration device and method, a lot of measurement data with continuous change can be obtained needless of moving the reflection units, the real condition can be simulated, and thecalibration efficiency and precision are improved effectively.

The invention provides a system for simultaneously conducting radar RCS calibration and exterior calibration based on an alignment calibration satellite. The invention changes a working mode wherein radar selects a RCS calibration satellite and an exterior calibration satellite respectively for RCS calibration and exterior measurement calibration. Based on technical features of the multifunctional calibration satellite, the radar can conduct RCS calibration and exterior measurement calibration at the same time, so that the efficiency of existing radar calibration is improved by double, and the economic consumption and the manpower support demand in the radar calibration process are halved.

The invention relates to the technical field of equipment calibration and discloses a radar calibration part and vehicle-mounted radar calibration equipment. The radar calibration part comprises a substrate and a fixing rotating shaft, wherein the substrate is used for reflecting a radar wave emitted from a vehicle-mounted radar of a vehicle to be calibrated to the vehicle-mounted radar after calibration is completed on a vertical surface of the substrate; the substrate is hinged with the fixing rotating shaft; the substrate can rotate around the central axis of the fixing rotating shaft and can at least stop in a first position, a second position and a third position; when the substrate stops in the first position, the substrate is vertically arranged; when the substrate stops in the second position, an included angle is formed between the substrate and a vertical direction; when the substrate stops in the third position, an included angle is formed between the substrate and the vertical direction; the substrate in the second position and the substrate in the third position are in symmetry relative to the substrate in the first position; and the included angle is smaller than a tolerant angle deviation value of the vehicle-mounted radar. By adopting the technical scheme, the adjusting precision of the radar calibration part can be increased.

The invention relates to a laser radar calibration method and device, equipment and a storage medium. A terminal, in a preset calibration scene, obtains a point cloud data frame pair of a to-be-calibrated laser radar; inertial navigation system data is obtained; and then through a calibration algorithm, a calibration result of the to-be-calibrated laser radar is determined according to the point cloud data frame pair and the inertial navigation system data. The calibration result of the to-be-calibrated laser radar can be automatically determined, so that the process of obtaining the calibration result of the laser radar by manual measurement is avoided, and the calibration efficiency of the laser radar is improved.