Patent classifications
G01S13/9023
In phase (I) and quadrature (Q) imbalance estimation in a radar system
A radar system is provided that includes transmission signal generation circuitry, a transmit channel coupled to the transmission generation circuitry to receive a continuous wave test signal, the transmit channel configurable to output a test signal based on the continuous wave signal in which a phase angle of the test signal is changed in discrete steps within a phase angle range, a receive channel coupled to the transmit channel via a feedback loop to receive the test signal, the receive channel including an in-phase (I) channel and a quadrature (Q) channel, a statistics collection module configured to collect energy measurements of the test signal output by the I channel and the test signal output by the Q channel at each phase angle, and a processor configured to estimate phase and gain imbalance of the I channel and the Q channel based on the collected energy measurements.
ANALYSIS DEVICE, ANALYSIS METHOD, AND STORAGE MEDIUM
An analysis device according to an aspect of the present disclosure includes: at least one memory configured to store instructions; and at least one processor configured to execute the instructions to: extract values of geospatial information at a plurality of points on a ground surface from a plurality of types of geospatial information, the plurality of types of geospatial information each representing at least a state of the ground surface or a state beneath the ground surface; and train a determination model based on height displacements at the plurality of points and the extracted values of the geospatial information in such a way that the determination model determines a set of the geospatial information contributing to the height displacement based on at least a part of the values of the geospatial information.
Method for monitoring the stability of an excavation front using radar interferometry
A method for filtering an interferometric radar acquisition, said method comprising the step of prearrangement of a radar system for carrying out acquisitions of images of a scenario by means of SAR interferometry, the radar system comprising at least one radar sensor arranged to emit and receive a radar signal, a control unit configured to analyse said signal received by said radar sensor by means of interferometric technique, a screen arranged to show to a user said images of said scenario.
SYNTHETIC-APERTURE RADAR SIGNAL PROCESSING APPARATUS
A synthetic-aperture radar signal processing apparatus in accordance with the present invention estimates the height of a scatterer in a synthetic aperture radar image observed at sets of sensors, each corresponding to a baseline length, and extracts a pixel corresponding to the scatterer at the height from the synthetic aperture radar image. The synthetic-aperture radar signal processing apparatus generates a topographic fringe of the synthetic aperture radar image calculates the phase of the topographic fringe that correspond to the specific height, and then extracts a pixel having the phase from the topographic fringe, resulting in the extraction of the pixel at the specific height. This configuration can extract a specific height corresponding to a combination of the phases generated by multiple topographic fringes and measure the height of the scatterer where the two sensors having the shortest baseline determine a measurable height.
SAR DATA SEARCH APPARATUS, METHOD, AND RECORDING MEDIUM
In order to enable to change a search condition of a set of SAR data, depending on a purpose of generating InSAR data, an SAR data search method according to an exemplary aspect of the invention includes: receiving an input of a search condition comprising a search purpose and an observation date/time condition, switching the observation date/time condition to be used as the search condition, depending on the search purpose, and extracting, from a metadata storage unit configured to store metadata comprising an observation date/time associated with identification information of an SAR data, the identification information of a set of the SAR data that satisfies the search condition, and outputting the extracted identification information of each piece of the SAR data in the set.
SAR image analysis system, image processing apparatus, image processing method, and image processing program
This invention is directed to an image processing apparatus that generates an evaluation index of a persistent scatterer likelihood without any influence of a large phase change with respect to a target whose displacement is nonlinear, a target whose elevation is high, or a target whose displacement is large. The image processing apparatus includes a phase array accumulator that accumulates phase arrays of respective pixels over a plurality of images, a clustering unit that classifies the respective pixels into a plurality of clusters based on the phase arrays, and a phase correlation calculator that calculates a correlation between a phase change in each of the plurality of clusters and the phase array at the respective pixels.
OPTIMIZATION METHOD AND APPARATUS FOR INTERFEROMETRIC SYNTHETIC APERTURE RADAR (InSAR) TIME-SERIES PHASE
Disclosed are an optimization method and apparatus for an Interferometric Synthetic Aperture Radar (InSAR) time-series phase. The optimization method includes: obtaining a time-series SAR data set, and performing registration and L-looks processing on the time-series SAR data set to obtain an L-looks intensity data set and an interferometric data set respectively; taking the L-looks intensity data set as a reference, obtaining a preset digital elevation model (DEM) and a preset land cover image, performing registration and geocoding on the preset DEM to obtain a digital elevation in a SAR image coordinate system, and performing registration and geocoding on the preset land cover image to obtain a land cover image in the SAR image coordinate system; performing a differential operation on the interferometric data set to obtain a differential interferometric data set; and estimating a covariance matrix at each spatial pixel position, and estimating and obtaining an optimized time-series phase.
Method and apparatus for phase unwrapping of synthetic aperture radar (SAR) interferogram based on SAR offset tracking surface displacement model
The present disclosure relates to a method and apparatus for phase unwrapping of an SAR interferogram based on an SAR offset tracking surface displacement model, in which the apparatus according to the present disclosure includes a Synthetic Aperture Radar (SAR) image acquisition unit that acquires two SAR images of a same object acquired at different times, a single look complex (SLC) image production unit that produces two SLC images corresponding to each of the two SAR images, an interferogram production unit that generates an SAR interferogram using SAR interferometry for the two SLC images, a surface displacement model production unit that produces an offset tracking surface displacement model using SAR offset tracking method for the two SLC images, an unwrapped residual interferogram generation unit that generates a residual interferogram by subtracting the SAR interferogram and the offset tracking surface displacement model, and generates an unwrapped residual interferogram by unwrapping the generated residual interferogram, and an unwrapped interferogram generation unit that generates an unwrapped SAR interferogram by adding the unwrapped residual interferogram to the offset tracking surface displacement model.
Coherence change detection techniques
Techniques for determining coherency between composite images having phase and amplitude components are disclosed. The coherency can be determined based on the amplitude components of the images, by providing first and second amplitude images indicative of amplitude values of pixels of a respective first and second composite images, applying to each of the first and second amplitude images a first directional derivative operator and a second directional derivative operator, thereby generating for each of the amplitude images respective first directional derivative image and second directional derivative image thereof, and generating a first coherency map based at least on the directional derivative images of the first and second amplitude images. The first coherency map is indicative of decorrelation between the first and second composite images.
SYSTEM AND METHOD FOR SELF-CONTAINED HIGH-PRECISION NAVIGATION
A self-contained, high precision navigation method and system for a mobile vehicle comprising an active coherent imaging sensor array with multiple receivers that observes the surrounding environment and a digital processing component that processes the received signals to form interferometric images and determine the precise three-dimensional location and three-dimensional orientation of the vehicle within that environment.