25 results about "Spaceborne radar" patented technology

The application discloses a kind of ground and satellite-borne measurement precipitation data fusion algorithm under bayesian framework, comprising the following steps: selecting time and space matching satellite-borne measurement precipitation and ground radar measurement precipitation data, when matching, set certain space window and time window, time window is within ±6min with the time difference that ground radar starts once body scanning time that satellite-borne measurement sweeps matching space window, space window is the region that with ground radar as center, the circular region of r radius and the region that satellite-borne radar survey strip is intersected, the ground and satellite-borne measurement precipitation data fusion algorithm under bayesian framework of the application, based on hierarchical bayesian method, the fusion of ground radar and satellite-borne measurement precipitation data, improve satellite-borne measurement instantaneous precipitation precision, obtain the high-precision, high-resolution precipitation estimation result of comprehensive multi-source precipitation observation, and can quantitatively give the uncertainty size that fusion result contains, to better be applied to hydrological model.

The application discloses a calibrator star-based altimeter calibration system and method, which utilizes a calibrator star carrying a calibrator to correct the system error of a spaceborne radar altimeter, thereby completing the calibration of the altimeter to the earth. The calibrator can modulate and retransmit the pulse emitted by the altimeter, and the calibration factor can be calculated according to the echo of the calibrator without relying on the ground calibration field, and then the calibration task can be completed by substituting into the ground target echo equation. The method utilizes the calibrator star to convert the calibration task from the original single "air-ground" data acquisition to an integrated calibration system of "altimeter-load platform-ground target", and the calibrator is moved from the ground to the space, so that the ground clutter can be reduced or even eliminated, the system error and the atmospheric error can be separated, and the coupling problem of the system error and the atmospheric error can be indirectly completed.

The application provides a kind of satellite-borne radar working state autonomous recovery method, comprising the following steps: S1, determine the radar state recovery key variable of the satellite-borne radar;S2, add key variable saving module in the embedded software, for regularly storing the latest data of the radar state recovery key variable, and regularly setting watchdog fly monitoring flag and overall pre-reset instruction flag;S3, add logic branch submodule in the embedded software, for reading the watchdog fly monitoring flag and overall pre-reset instruction flag, and further executing radar normal power-on start initialization branch or watchdog fly reset branch or pre-reset instruction reset branch.The application can make the satellite-borne radar autonomously recover the working state after encountering single event upset failure, avoid causing the interruption of satellite-borne radar target tracking monitoring, improve the reliability of satellite-borne radar product on-orbit operation, and has the simplicity, independence, flexibility and wide applicability of implementation.

The application discloses a global average sea clutter near real-time estimation method, system, device and storage medium, including the following steps: obtaining multi-source satellite-borne radar historical backscattering coefficient data, and performing time and space matching and binning on the ERA5 wind field; an average sea clutter estimation model is established according to a geophysical model function fitting; the satellite-borne microwave scatterometer wind field is corrected in deviation and fused with a numerical weather prediction wind field, so that a high-coverage, continuous near real-time global sea surface wind field is obtained; the relative azimuth is calculated in combination with radar observation parameters and fused wind direction, and global average sea clutter data is obtained by using the model; the application improves the precision and application range of sea clutter estimation under the condition of medium and small incident angles, provides a high-quality input wind field through a multi-source wind field fusion technology, realizes rapid, stable and near real-time estimation of global average sea clutter, has high timeliness and business feasibility, and can meet the needs of near real-time sea clutter monitoring and ocean remote sensing application.

This invention discloses a factor graph-based distributed spaceborne radar network air target altitude estimation algorithm, comprising the following steps: Step 1, constructing an air target motion model and a spaceborne radar measurement model in the geocentric fourth equatorial coordinate system, and constructing a factor graph-based spaceborne radar target tracking model; Step 2, based on the factor graph, introducing the coupling function relationship between local variables of the air target, and obtaining the posterior marginal distribution of the local variables; using a nonparametric confidence propagation algorithm to calculate the posterior marginal distribution of the local variables, and obtaining the estimated value of the local variables based on the calculation result of the posterior marginal distribution; Step 3, based on the estimated value of the local variables, using an iterative approximation method to obtain the target altitude of the air target in the geodetic coordinate system. This solves the problems in existing technologies such as large elevation angle measurement errors for single spaceborne radars, difficulty in accurately tracking air targets, and inaccurate altitude estimation.

The invention provides a method and system for improving the wide-area search performance of a medium-orbit spaceborne radar, and the method comprises the steps: S1, analyzing the wide-area search performance influence factors of the medium-orbit spaceborne radar, and obtaining an analysis result; s2, proposing a performance improvement method based on the analysis result; and S3, evaluating the proposed performance improvement method, and outputting an evaluation result. The medium-orbit spaceborne radar wide-area search performance improving method and system are provided for the first time, and time resource waste caused by beam filling is reduced through an ingenious beam arrangement strategy and an A-transmitting and B-receiving control scheme.

1. Name of the product in this design: Modular antenna test fixture for spaceborne radar antenna. 2. Application of this design: Suitable for modular assembly testing fixtures for spaceborne radar antennas. 3. The key design features of this product are its appearance and shape. 4. The image or photograph that best illustrates the design's key points: 3D view 1.

This invention provides a method and system for detecting ships using spaceborne ship monitoring radar, comprising: setting the pulse repetition frequency of the sea-penetrating radar on a zebra map; setting the sea-penetrating radar transmission signal; transmitting the signal and acquiring the sea-penetrating echo according to the settings; calculating the range ambiguity set where the main ambiguity energy is located; suppressing land ambiguity for the range ambiguity in the range ambiguity set; and detecting ships in the effective observation area of ​​the sea-penetrating echo after land ambiguity suppression. This invention noise-enhances the echo signal, solving the problem of false alarm detection and effectively improving the observation performance of space-based sea-surface detection radar; by using signal encoding and existing SAR image databases for range ambiguity suppression techniques, and by using a matched filter corresponding to the effective observation area to achieve range focusing in the effective observation area, it solves the problem of high range ambiguity requirements and realizes a spaceborne radar system for ship monitoring with low false alarm rates.

The invention provides a target three-dimensional positioning method and system based on satellite-borne radar multi-node combined processing, and the method comprises the steps: deploying a plurality of satellites, and obtaining a lower visual angle and a space cone angle of a target relative to the satellites; calculating a three-dimensional coordinate of the target in the satellite antenna panel coordinate system; constructing a layered conversion model from the earth fixed connection coordinate system to each satellite antenna panel coordinate system; constructing an overdetermined equation set taking a target coordinate under the earth fixed connection system as an unknown quantity; solving the equation set by adopting a least square algorithm to obtain a three-dimensional coordinate of the target under the earth fixed connection coordinate system; and finally, converting the data into longitude, latitude and height. According to the method, redundant information is formed through combined observation of multiple satellites, multi-satellite heterogenous observation is unified to the same reference by introducing a strict layered coordinate conversion model considering orbits, earth rotation and installation attitudes, solving is conducted in combination with an overdetermined equation set, and the precision and robustness of target three-dimensional positioning are remarkably improved.

The present application relates to the technical field of signal processing, in particular to a kind of azimuth ambiguity calculation method and device of space-borne synthetic aperture radar.Method comprising: obtaining the set parameter of space-borne radar;For each working mode, it is executed: based on set parameter, determine the position vector of target scene center point when space-borne radar irradiates target scene center point in current working mode, the latitude and longitude of target scene center point and the position vector of equivalent rotating point;Determine the position vector of each target position point in target scene;Determine the irradiation time of space-borne radar irradiating each target position point, and determine the off-axis angle of current target position point and radar beam pointing angle at each irradiation time in irradiation time;Determine the azimuth ambiguity of each target position point, to determine the azimuth ambiguity variation curve in current working mode.This scheme can improve the azimuth ambiguity calculation efficiency of space-borne synthetic aperture radar in different working modes by using general calculation method.

The invention relates to a satellite-borne radar high-precision near-field phase calibration method, and belongs to the technical field of space microwave remote sensing. Building a phase calibration system; the amplitude and phase value of each TR assembly channel are obtained, geometric profile data of the phased-array antenna are measured through a theodolite, and the three-dimensional geometric position (xn, yn, zn) of each TR assembly channel is obtained; calculating phase calibration data according to the three-dimensional geometric position (xn, yn, zn) of each TR assembly channel; performing phase calibration on the phase data measured by each TR assembly according to the phase calibration data and the antenna near-field measurement data to obtain calibrated antenna phase data, and measuring an antenna pattern according to the calibrated antenna phase data; according to the invention, high-precision extraction of the profile error of the phased-array antenna is realized, and the result of the profile error of the antenna is converted into the phase error value of the antenna, so that the phase error value is substituted into an antenna near-field calibration system, and the problem of high-precision trimming of the Ku-band satellite-borne phased-array antenna is solved.

The invention discloses a satellite-borne radar air target detection processing algorithm DSP engineering design system, which is realized by adopting a TI C66x series multi-core DSP, and is used for receiving input radar system parameters, receiving an input processing mode configuration instruction, entering a specified processing mode according to the processing mode configuration instruction, and after entering the specified processing mode, carrying out digital processing on the satellite-borne radar air target detection processing algorithm DSP engineering design system. Acquiring stored original echo data of the target, and performing collaborative parallel processing on the original echo data by utilizing a plurality of cores in the multi-core DSP according to an algorithm code corresponding to a specified processing mode to obtain a target detection result; the system includes six processing modes for executing six different overhead target detection processing algorithms. According to the invention, a multi-algorithm engineering implementation scheme for detecting the free target by the spaceborne radar is realized through the multi-core DSP single board, the limitations of insufficient motion compensation precision and incomplete processing flow in the prior art can be overcome, and the resource consumption and the operation time can be reduced.

The invention discloses an accelerated recovery type landslide self-repairing time prediction method, and belongs to the technical field of image geodetic survey and geological disaster monitoring and early warning thereof. Comprising the following steps: acquiring an earth surface deformation time sequence and an earth surface annual deformation rate of a research area by utilizing a multi-stage lifting orbit spaceborne radar image and adopting an MT-InSAR technology and an SAR POT technology, establishing an active landslide catalogue of the research area based on the earth surface deformation time sequence and the earth surface annual deformation rate by utilizing a spatial clustering algorithm, extracting average earth surface time sequence deformation in an active landslide range, and judging accelerated recovery type landslide. Fitting the earth surface deformation time sequence of the accelerated recovery type landslide, calculating the deformation evolution condition of the accelerated recovery type landslide based on the fitted exponential decay function, integrating all the information of the accelerated recovery type landslide, and establishing an accelerated recovery type landslide database. According to the method, automatic identification of the accelerated recovery type landslide and quantitative prediction of the recovery time are realized, and the accuracy and timeliness of landslide disaster risk assessment are improved.

The application provides a kind of distributed spaceborne radar air mobile target imaging method, system and electronic equipment, related to synthetic aperture radar (SAR) imaging technical field, the method comprises: obtaining three same orbit satellite and air mobile target, and constructs distributed spaceborne radar air mobile target imaging model, obtains multi-channel original echo data;The multi-channel original echo data is pretreated, and the equivalent time axis is constructed according to the multi-channel original echo data after pretreatment, and coherent fusion processing is carried out, to obtain fusion echo data;Reference point and image entropy are obtained, the fusion echo data is matched filtering processing, and based on reference point and image entropy, envelope alignment and phase correction processing are executed, and azimuth fast fourier transform is carried out, to obtain target SAR image.The application realizes the high resolution, high robustness SAR imaging of air mobile target, solves the problems of low resolution of single satellite, multi-satellite asynchronization and mobile target imaging defocus.

A new measurement approach is disclosed that facilitates significantly smaller size, weight, and power (SWaP) spaceborne radar systems that can provide wide swath, high resolution observations. Multiple beams employed in the scan and the complex volume and / or surface backscatter signals of each beam is recorded. Each beam is electronically swept in azimuth where each beam is held at a constant incidence angle over the azimuth sector that covers the swath. Once the sweep is complete, the platform moves forward, by one along track pixel, and the sweep is repeated in order to provide continuous mapping of the volume and surface covered by the swath. Complex volume backscatter is recorded and mapped to each altitude layer to provide full mapping of the atmosphere.

The application provides a target stereoscopic positioning method and system based on multi-node joint processing of a spaceborne radar, wherein the method comprises the following steps: deploying multiple satellites, obtaining a downward angle and a space cone angle of a target relative to the satellites; calculating three-dimensional coordinates of the target in a satellite antenna panel coordinate system; constructing a hierarchical conversion model from a geodetic coordinate system to a coordinate system of each satellite antenna panel; constructing an over-determined equation group with the target coordinates in the geodetic coordinate system as unknown quantities; solving the equation group by using a least square algorithm to obtain the three-dimensional coordinates of the target in the geodetic coordinate system; and finally converting the three-dimensional coordinates into longitude, latitude and height. The application utilizes the joint observation of multiple satellites to form redundant information, and introduces a rigorous hierarchical coordinate conversion model considering the orbit, the earth rotation and the installation attitude, so that the multi-satellite heterogeneous observation is unified to the same reference, and the over-determined equation group is solved, thereby significantly improving the accuracy and robustness of the target stereoscopic positioning.

The present application belongs to the technical field of spaceborne radar data processing and remote sensing mapping, and particularly relates to a grain and oil crop scattering wave trough identification method based on harmonic amplitude and phase analysis. The present application realizes scattering time series reconstruction and denoising through harmonic fitting, and realizes scattering waveform detection and rapid identification of scattering wave trough through amplitude and phase analysis. The present application flexibly and efficiently realizes scattering time series denoising without presetting a sliding window size and without assuming a local fitting function, and rapidly and accurately identifies grain and oil crop scattering wave troughs without relying on complex time series point-by-point operation and secondary discrimination, thereby providing support for long time series and large area agricultural application of radar data. The present application effectively overcomes the problems in the corresponding industry caused by the fact that the existing window statistical method and local fitting method are difficult to determine an adaptive sliding window and a fitting function, and the fact that the difference search method needs complex time series point-by-point operation and secondary discrimination.

The invention discloses a global average sea clutter near-real-time estimation method, system and device and a storage medium, and the method comprises the following steps: obtaining historical backscattering coefficient data of a multi-source spaceborne radar, carrying out the space-time matching with an ERA5 wind field, and carrying out the box separation; fitting and establishing an average sea clutter estimation model according to a geophysical mode function; carrying out deviation correction on the satellite-borne microwave scatterometer wind field and fusing the satellite-borne microwave scatterometer wind field with a numerical weather forecast wind field to obtain a high-coverage continuous near-real-time global sea surface wind field; calculating a relative azimuth angle by combining radar observation parameters and a fused wind direction, and obtaining global average sea clutter data by using the model; the method improves the precision and application range of sea clutter estimation under medium and small incidence angle conditions, provides a high-quality input wind field through a multi-source wind field fusion technology, realizes rapid, stable and near-real-time estimation of global average sea clutter, has high timeliness and business feasibility, and is suitable for large-scale popularization and application. And the requirements of near-real-time sea clutter monitoring and ocean remote sensing application can be met.

The present application relates to the field of hydrological remote sensing and geographic information technology, and more particularly to a water body and water level cooperative extraction method and system. The method comprises the following steps: collecting multi-source remote sensing data of a target area within a preset time period; extracting water body information of optical image data in the multi-source remote sensing data to generate a water surface mask, and quantitatively extracting water body morphological characteristic parameters based on the water surface mask; extracting observation data within the spatio-temporal range of the water surface mask in the spaceborne radar altimeter planar water level data that meets the water body morphological characteristic parameters to construct an initial planar water level field; performing spatio-temporal matching and spatial correction on the spaceborne laser radar point elevation data in the multi-source remote sensing data and the initial planar water level field; and performing spatio-temporal fusion according to the spatially corrected planar water level field and the spatio-temporal change information of the water surface mask. The present application can break through the limitations of a single data source in terms of spatio-temporal resolution and continuous monitoring capability, while improving the water level inversion accuracy and reliability.

This invention provides a method and system for acquiring satellite-borne antenna pointing information using distributed multi-star sensors, comprising: a satellite equipped with a radar antenna, a platform star sensor, a measurement antenna, and a measurement star sensor; establishing a measurement star sensor observation coordinate system and a measurement antenna coordinate system; obtaining a first transformation relationship based on the relationship between the measurement antenna and the measurement star sensor; obtaining a second transformation relationship through bidirectional microwave transmission and reception between the measurement antenna and the radar antenna; the measurement star sensor and the platform star sensor synchronously observing stars and matching them with the same star map to obtain a third transformation relationship; and using the first, second, and third transformation relationships, performing a fusion transformation according to a formula to obtain the radar antenna beam pointing information in the platform star sensor observation coordinate system. This invention utilizes multiple star sensors distributed at different locations on the satellite for synchronous measurement and data fusion to obtain the on-orbit beam pointing information of the satellite-borne radar antenna.

The present application relates to echo dynamic adjustment method, device, equipment, medium and radar echo simulator, the method comprises: obtaining the radar working parameter and transmitting trigger pulse corresponding to the satellite-borne radar in the current period, according to time width and bandwidth, from the pre-stored different time width and bandwidth corresponding baseband echo data to determine target baseband echo data;According to the range tracking error, the target baseband echo data is signal-processed, and the processed signal is obtained, and the range tracking error corresponding to the processed signal is less than a set value;According to the transmitting trigger pulse, the sampling starting time is adjusted, and the adjusted sampling starting time is obtained;According to the adjusted sampling starting time and the processed signal, the frequency of the echo signal of the current period is adjusted. Through the method of the present application, the synchronization of the echo simulator and the satellite-borne radar in the working sequence and the working parameter can be realized, so that the test of the radar load is comprehensive and sufficient.

The application relates to the field of spaceborne radars, and particularly discloses a signal synthesis method applied to a high-resolution wide-swath SAR system, which comprises the following steps: acquiring time sequence functions of inner calibration signals and echo receiving signals of multiple feed sources; the multiple feed sources emit the inner calibration signals through multiple beams; the multiple feed sources and the multiple beams are in one-to-one correspondence; the multiple beams are in one-to-one correspondence with multiple time domains; receiving signals through the multiple beams; each beam is used for receiving part of information of the receiving signals; performing discrete Fourier transform on the inner calibration signals, the time sequence functions and the receiving signals to solve a scattering coefficient matrix; performing inverse Fourier transform on the scattering coefficient matrix to obtain scene scattering signals; and the scene scattering signals contain multiple parts of information from the multiple beams respectively. The scheme provided by the application has high matching precision, can maximize the signal-to-noise ratio of the multiple beam overlapping parts, has the advantages of reducing sidelobes, and can meet the demand of high-resolution imaging.

The invention discloses a climate data set construction method based on three-dimensional structure characteristic parameters of a rainfall system, and relates to the technical field of satellite meteorological remote sensing and climate data set construction. The method has the following technical effects in the aspects of consistency analysis and fusion application of multi-source spaceborne radar observation data: different from pixel-level point-like or profile-level observation, parameter extraction and evaluation are carried out by taking a rainfall system as a unit, spatial organization characteristics and structural forms of rainfall are retained, and the accuracy and the reliability of the observation data are improved. The evolution of the precipitation process can be understood from the system scale; by constructing a system-level sample matching pair of TRMM PR and GPM DPR radars in the overlapping observation period, item-by-item consistency evaluation of three-dimensional structure characteristic parameters such as the horizontal area, the vertical height and the average rainfall intensity of a rainfall system is achieved for the first time, and an objective quantitative basis is provided for subsequent multi-source data fusion.

The invention provides a synthetic aperture radar (SAR) four-dimensional imaging interference suppression method and system, and belongs to the technical field of satellite-borne radar system design and signal processing. The method comprises the steps that target four-dimensional information is coarsely reconstructed through pixel-by-pixel joint optimization; interference enhancement and residual calculation; carrying out space-time clustering interference detection and suppression; and target four-dimensional information is accurately reconstructed through pixel-by-pixel joint optimization. The system comprises a pixel-by-pixel optimization module for realizing the method, an interference enhancement and residual calculation module, a space-time clustering interference detection and suppression module and the like. According to the method, the problem of radio frequency interference suppression faced by SAR four-dimensional imaging is solved, the imaging precision and robustness in a complex scene are remarkably improved, and the method is suitable for the fields of resource investigation, disaster monitoring and the like.

The present application belongs to the technical field of spaceborne radar data processing and remote sensing mapping, and particularly relates to a paddy field recognition method based on time series harmonic fitting and terrain temperature mask. The present application realizes noise suppression and periodic characteristic extraction of time series scattering through high-value interference removal and time series harmonic fitting, obtains a harmonic mask image, a terrain mask image and a temperature mask image through spatial mask analysis respectively, and completes paddy field recognition in combination with the three masks, and can be suitable for large-scale paddy field recognition. The method provided by the present application effectively removes the space-time noise of radar data, reduces the complexity of time series analysis, realizes large-area high-resolution paddy field recognition without obtaining prior information of rice phenology, can be applied to large-scale and long-time-span rice planting area monitoring, and provides strong information support for policy making of the agricultural department.