138 results about "Marine radar" patented technology

A real-time radar surveillance system comprises at least one land-based non-coherent radar sensor apparatus adapted for detecting maneuvering targets and targets of small or low radar cross-section. The radar sensor apparatus includes a marine radar device, a digitizer connected to the marine radar device for receiving therefrom samples of radar video echo signals, and computer programmed to implement a software-configurable radar processor generating target data including detection data and track data, the computer being connectable to a computer network including a database. The processor is figured to transmit at least a portion of the target data over the network to the database, the database being accessible via the network by at least one user application that receives target data from the database, the user application providing a user interface for at least one user of the system.

The invention discloses a sea surface wind measurement method based on an X-band marine radar and belongs to the technical field of marine dynamic environment remote sensing. The measurement method comprises three parts of radar image preprocessing, wind direction measurement and wind speed measurement. In the wind direction measurement indexes, image gradient, gray level and smoothing item are organically combined, the proportion of the image gradient, the gray level and the smoothing item is adjusted through proportionality factor and a model suitable for the sea surface wind characteristic is established, compared with the prior art, the wind direction measurement precision is improved by 68.4 percent. In the wind speed measurement indexes, when the radar is used for measuring individually, normalized radar cross section (NRCS), the actually measured wind direction and signal to noise ratio (SNR) serve as back propagation (BP) network input, compared with the traditional algorithm, the wind speed measurement precision is improved by over 84 percent. In the wind speed measurement indexes, sea boundary layer parameters serve as addition input of the BP network, so that the wind speed measurement precision of the marine radar can be further improved, and the measurement precision is improved by over 48 percent by taking air-sea temperature difference, salinity, sea level and atmospheric pressure into consideration.

A high resolution, low power marine radar for use in applications such as the newly mandated barge/river radars that are to be used in very confined spaces such as canals. An example radar system includes frequency-modulated/continuous-wave (FM/CW) radar that uses very low transmitter power (a fraction of a watt) and has an exceptionally short sensing range of a few feet or even inches if needed.

Marine radar systems and methods for producing low power, high resolution range profile estimates. Non-linear Frequency Modulation (NLFM) pulse compression pulses are frequency stepped to form a low power, wide-bandwidth waveform. Periodically, calibration filters are determined and applied to return signals for correcting non-ideal effects in the radar transmitter and receiver.

The invention discloses a sea clutter suppression method for a marine radar. Most of the existing marine radars can not process the nearby sea clutter, and the existing sea clutter suppression methods usually suppress the sea clutter according to a fixed template, which can result in the great attenuation in the amplitude of a nearby target signal or even result in miss detection. The sea clutter suppression method provided for overcoming the above disadvantages comprises the following steps: initializing parameters and data, estimating parameters, suppressing the sea clutter and updating an estimation sample. The method can estimate the sea clutter according to different sea clutter distributions selected according to different sea conditions, and determine whether the sample data need to be updated for re-estimation according to the suppression effect, thereby maximally reducing the influence to the target while suppressing the sea clutter as much as possible, and obviating the great attenuation in the amplitude of the nearby target signal.

The invention discloses an anti-collision alarming radar system for ships, comprising a marine radar, an anti-collision alarming device and a three-port adaptor that connects a transmitter/a receiverof the marine radar with a display terminal and the anti-collision alarming device. The anti-collision alarming device comprises a display, an alarming apparatus, a data collecting board and a computer board, wherein the data collecting board is used for collecting detection signals, echo signals and bow signals from the radar to calculate the target distance and the angle and sending frame data formed by radar scan to a computer board; and the computer board is used for extracting the target point track data from the frame data to predict the future trend of target motion by associating and smoothing process via a track association algorithm and to evaluate and judge the risk level of the target in real time and then controlling the display and the alarming apparatus to display information and send the alarm signal. The invention further discloses an anti-collision alarming radar device for ships. The invention can be realized with low cost and is of great importance to ensure safetyof navigation of the ships.

The invention relates to the field of radar engineering and a radar system of intermediate frequency coherent, in particular to an FPGA (field programmable gate array) based digital intermediate frequency coherent marine radar receiving and processing system. The system comprises an intermediate frequency amplifier module connected with the output end of a receiver radio-frequency front-end, and is characterized by further comprising an A/D (analog/digital) sampling chip and an under-digital frequency conversion module, the under-digital frequency conversion module comprises digital-controlled oscillator, a low-pass filter and a digital decimation filter which are based on FPGA and are arranged in sequence; intermediate frequency power signals outputted by the receiver radio-frequency front-end are converted into voltage signals via the intermediate frequency amplifier module and then transmitted to the A/D sampling chip, and the voltage signals are acquired and transmitted to the under-digital frequency conversion module. The system is simple in structure and high in flexibility, image-frequency rejection ratio of I/Q signals is increased as compared with I/Q baseband signals respectively acquired with a simulation conversion method, and the system has the advantages of low drift, low distortion and the like, and useful information in return signals can be extracted to the greatest extent to be used for subsequent radar signal processing operations.

The invention provides a ground verification instrument of a satellite-based marine radar height gauge, which is used for performing absolute calibration, performance examination and function test on the satellite-based marine radar height gauge in a laboratory. The ground verification instrument of the satellite-based marine radar height gauge comprises a time service unit, a transceiving control unit, a transmitting unit, a receiving unit, a frequency heald unit and a numerical control unit. The frequency heald unit utilizes an ultra-stable crystal oscillator signal provided by a radar height gauge to be verified as a clock. The time service unit takes charge of providing accurate synchronous time service for the numerical control unit and the radar height gauge. The transceiving control unit takes charge of respectively and simultaneously sending signals transmitted by the transmitting unit to the receiving unit and the radar height gauge and also controlling the receiving unit to receive the signals transmitted by the radar height gauge or the signals transmitted by the transmitting unit. The numerical control unit takes charge of eliminating channel influences of a verification instrument system, generating calibration signals, simulating echo signals of various target scenes and controlling the transceiving control unit, the receiving unit, the transmitting unit and the frequency heald unit.

The invention discloses a method and system for identifying a marine oil spill object by a marine radar. The method of the invention comprises the following steps: A, converting output image signals from radar projection into Descartes projection; B, correcting images and compensating motion; C, processing the radar images corrected in the step B by a Gamma filtering method, reserving marginal information and simultaneously filtering high-frequency noise of the radar images; D, detecting a strong signal area in the images, according to the distribution of signal strength in the images, determining the saturated state strength as the strength threshold of the signal area, and directly deleting the signal data exceeding the strength threshold; and E, carrying out image segmentation by a gray level co-occurrence matrix method to abstract the marine oil spill object. The system comprises a radar main controller, a marine radar controller, a junction box, an acquisition device, a processing device and a display device. The invention utilizes the noise wave information such as ocean wave and the like to obtain a small object, identifies the oil spill object by a texture algorithm, and can better abstract the marine oil spill object.

The present invention relates to a monitoring technology system of the marine radar bleeding and belongs to the technical field of the marine environment monitoring. The system consists primarily of a marine radar, a communication interface, a radar bleeding image recording instrument and a computer; the sea level bleeding monitoring is completed, the image is gathered and transmitted; and the numerical processing of the bleeding image is realized, thus obtaining the correlation parameters of the generant position, the scope, the distribution pattern, the bleeding drift direction, and the speed of the bleeding; realizing the dynamic display of the bleeding image as well as the image transmission function, then finishing the numerical processing technology of the marine radar bleeding monitoring image as a whole. The present invention has the beneficial effects that the system can provide efficiently the accurate and real time newest dynamic information of the comparatively big scope sea level bleeding region at all-weather such as the inshore water, the sea route, the anchoring zone, and so on, and provide the technical support for the bleeding monitoring and the system decision-making of the bleeding accident emergency reaction.

An all-solid-state marine radar technology based on a non-rotating cylindrical array antenna is described. Multiple transmit/receive (T/R) modules are used to form the antenna beam, which allows the beam sequencing, the dwell time in each beam position, the resolution, and the beam shape to be varied in order to make best use of the available energy. Waveforms with a high duty ratio can be used on transmit in order to make efficient use of solid-state power amplifiers. High resolution in both range and Doppler provides high measurement accuracy and superior performance in clutter. Alternate embodiments, including continuous waveform embodiments are disclosed.

The invention discloses an unmanned ship path programming system and a method capable of taking sea condition factors into consideration. The unmanned ship path programming system comprises an unmanned surface vehicle, a path programming module, a control module, a GPS/IMU module, an environment perceiving module, and a sea condition monitoring module; the path programming module and the control module are arranged in the unmanned surface vehicle, and are used for programming of a series path points based on environment information and calculated ocean wave grade, and controlling the unmannedsurface vehicle to travel along the path points; the environment perceiving module is composed of an electric sea chart and a laser sensor, wherein the electric sea chart is arranged in the unmanned surface vehicle, and is used for providing static state barrier information, and the laser sensor is arranged on the front part of the deck of the unmanned surface vehicle through a support, and is used for providing barrier information; the GPS/IMU sensor is arranged on the top of the unmanned surface vehicle, and is used for providing other modules with the pose information of the unmanned surface vehicle; a navigation radar is adopted by the sea condition monitoring module, and the sea condition monitoring module is used for calculating ocean wave grade. The unmanned ship path programming system and the method capable of taking sea condition factors into consideration are reliable and reasonable, and are capable of improving the rationality of unmanned surface vehicle path programming.

The invention discloses a sea radar image sea surface wind speed inversion method based on an RBF neural network, and belongs to the field of sea surface wind speed inversion by using a remote sensingmeans. The invention discloses a sea radar image sea surface wind speed inversion method based on an RBF neural network. The method comprises four parts of sea radar image data preprocessing, RBF neural network input layer construction, RBF neural network model determination and sea surface wind speed information extraction. The sea surface wind speed inversion process is completed based on a model obtained by training a single hidden layer RBF neural network, and an RBF neural network input layer sample is constructed by adopting a normalization result of a sea surface wind field energy spectrum, sensor information and sea condition information; meanwhile, an application subtraction clustering algorithm is proposed, a neural network is determined according to the density index of an input sample and clustering judgment conditions to determine the number of hidden layer units and the center and expansion constant of a primary function, and a network output layer connection weight is obtained by using recursive least squares.

The invention belongs to the technical field of marine radar information fusion and provides a real-time track robust association technology suitable for a target on the sea surface under the condition that a system error exists, namely a multi-radar marine target robust association algorithm based on a credible association pair. According to the characteristics of target tracks of ships on the sea surface, under the condition that it is confirmed that the system error exists, a pair of tracks which come from different sensors and originate from the same target is defined as the credible track association pair, wherein the tracks are close to each other on the sea surface, and no other track exists within a certain range nearby the tracks. According to the multi-radar marine target robust association algorithm, the credible track association pair on the sea surface is extracted based on the unit average constant false alarm detection method, the credible track association pair is used for obtaining track deviation caused by the system error, and association of the tracks with the same source is realized based on the classic track association algorithm after error compensation is conducted on original radar data. Compared with the traditional multi-sensor track robust association algorithm, the multi-radar marine target robust association algorithm mainly has the advantages that the computing process is simple and convenient, computing time is short, and the requirement for the real-time performance of a radar tracking fusion system can be met.

The invention discloses a marine radar detection system and a detection method thereof. The system comprises a radar antenna, a radar receiver, a radar transmitter and an ARPA (Advanced Research Projects Agency) radar terminal. The radar transmitter receives a control instruction and outputs state detection data; the radar receiver receives the control instruction and outputs the state detection data; and the ARPA radar terminal is provided with self-adaptive detection processing and control software and transmits a working state setting instruction to a filter for single detection and target track processing in the radar transmitter, the radar receiver and the ARPA radar terminal. The method comprises the steps of land and shoreline detection, echo character parameter calculation, the detection and tracking interaction of a correlative filter, target quality parameter evaluation and radar self-adaptive control. Aiming at a target with different characteristics, the invention acquires the integrated optimization of the detection performance and the resolution performance as well as the detection performance and the tracking performance and forms a self-adaptive marine radar detection system facing to the target.

The invention provides a marine radar target echo simulation method, which comprises the following steps: 1) inputting collected due north signals, orientation increment codes and main pulse signals of a radar to be measured and target distance, moving speed and target orientation parameters to be simulated into a display control track simulation module, wherein the display control track simulation module comprises a DSP, an FPGA, an SDC/RDC and additional circuits. The DSP is used for calculating track information of a simulation target according to the input simulation target requirement; and the FPGA and the SDC/RDC receive the due north signals and the orientation increment codes and then, calculate orientation information, and send the calculated track information and the orientationinformation of the simulation target to a DDM module. The method simulates the detected target echo signals of a marine radar through a computer, and provides known simulation target information to the radar to be measured, thereby realizing detection of the radar to be measured under no real target. The simulated target echo signal is very close to the real information, thereby solving the problem of detection of shoreside of the radar.

The invention discloses a sea area monitoring system applied to border defense and based on a digital marine radar technology. The sea area monitoring system is formed by the following steps of: constructing a remote radar station system; constructing a monitoring radar station system; and constructing a remote control client side and server system. The sea area monitoring system is based on multipoint X waveband and S waveband monitoring radar stations, and realizes an active sea surface monitoring network by network connection. Simultaneously, the sea area monitoring system integrates a digital image processing technology and a software technology, realizes autonomous management on the monitoring radar stations, actively captures goals, is in butt joint with a special monitoring network and uploads monitoring information in real time.

The invention relates to a color indexing-based marine radar echo image transmission method. The method includes the following steps that: echo brightness and blanking time of echo afterglow are determined, and an echo image color index table is established; 16-bit RGB data of each pixel of an echo image are converted into 8-bit image index data; a data processing unit transmits two adjacent 8-bit image index data to a display terminal together; the display terminal receives the image index data, and segments the image index data into a group of high single-byte data and a group of low single-byte data according to double-byte data width and performs mutual exchange on the high single-byte data and the low single-byte data, and inquires truth 16-bit RGB color values in the color index table; the converted RGB color values are combined so as to form an echo display image which is stored in a display cache and is subjected to display processing; and step one to step five are repeated until echo acquisition terminates. Compared with an original transmission method, with the transmission method of the invention adopted, only one half of data transmission channel bandwidth is occupied, and transmission efficiency is improved by 100%, and radar echo image data which are acquired with a high speed can be continuously and stably transmitted to the display terminal so as to be displayed.

The invention discloses a marine radar target rapid detection method based on a support vector machine. The method includes the steps that first, a field observation test is carried out offline, a certain amount of two types of radial echo samples on a single scanning line are selected, one type of radial echo samples contain target radar echoes, the other type of radial echo samples do not contain target pure sea clutter radar echoes, two appropriate radial echo characteristic parameters are extracted according to the characteristics of the samples, and a classifier model is obtained by training through an SVM; second, data to be measured on the radar single scanning line are acquired, the values of the data to be measured in the two radial echo characteristics in the first step are calculated and input to the classifier model, and a corresponding decision function value K is obtained; and final, the obtained decision function value K is compared with a threshold value of a classifier, and whether a target exists on the single scanning line or not is judged. According to the method, the target detection efficiency can be effectively improved, and false alarms can be reduced.

The invention relates to a design method for a sea clutter inhibition curve of a marine radar based on wavelet transformation, and belongs to the technical field of signal processing of the marine navigation radar. Echo data of the radar in the measuring range is decomposed via discrete wavelet transformation, a high-frequency coefficient is zeroed, and a high-level approximate part is used to estimate power level of sea clutters. A corresponding adjustable sea clutter inhibition curve is calculated according to a range parameter and a sea clutter inhibition intensity parameter, and the estimated power level of the practical sea clutters is overlapped with the adjustable sea clutter inhibition curve to obtain a general sea clutter inhibition curve. The inhibition curve design method is highly adaptive to a traditional sea clutter inhibition method relied on statistical characteristics, it is not required to predict distribution which the power level of background clutters obeys in advance, the method has a good inhibition effect for near sea clutters, and the problem that sea clutters surrounding the circular center of a radar screen are hard to eliminate is overcome; and the design method is flexible to use, and includes different inhibition levels, so that a user can carry out sea clutter inhibition of different levels according to practical sea-condition information.

Embodiments of the invention disclose a method and apparatus for acquiring a channel monitoring target. The method includes the steps of acquiring a first video frame of an infrared thermal imaging video; determining a target area in the first video frame; generating a Gaussian pyramid corresponding to the target area; and extracting eigenvalues of the Gaussian pyramid to carry out the local visual contrast calculation of the eigenvalues, and determining a first monitoring target from the target area according to the calculation result. In other words, the scheme is that the monitoring targetis acquired through the infrared thermal imaging video, an infrared thermal imaging video acquisition device is less susceptible to the weather as compared with a marine radar and a CCTV system, the infrared thermal imaging is still clear even in the case of bad weather and low visibility, such as fog days, rainy days and nights. Therefore, by using the scheme provided by the invention, the channel monitoring target can be accurately obtained.

The invention provides a marine radar image rainfall identification method based on the K parameter. The K parameter is defined as 100 times of the specific value of the zero intensity percentage to the echo intensity mean. Firstly the offline observation experiment is performed, data statistical analysis is performed and the detection threshold T is determined, and then same-frequency interference suppression processing is performed on the radar original image to be identified; then the shielding area zero intensity percentage and the echo intensity mean are calculated and the K parameter isdetermined; and finally the K parameter is compared with the detection threshold T so as to determine whether the image is the rainfall image. The effect is verified by using the actually measured data. The accuracy of the rainfall image identification method is higher than that of the method using the echo intensity mean and the diversity factor for 16.6% and higher than that of the method independently using the zero intensity percentage for 3.4% so that the radar rainfall image in the marine process can be more accurately identified, and the wave inversion error caused by the rainfall can be reduced.