Patent classifications
G01S13/9094
Synthetic aperture radar signal processing device
A synthetic aperture radar signal processing device according to the present invention includes, a low-accuracy interpolation processing unit to perform interpolation processing on discrete data obtained from signals received by a synthetic aperture radar, a high-accuracy interpolation processing unit to perform interpolation processing on the discrete data with higher accuracy than the low-accuracy interpolation processing unit, a curvature determination unit to select either the high-accuracy interpolation processing unit or the low-accuracy interpolation processing unit in accordance with a first curvature that is a curvature of the discrete data at a target area for the interpolation processing, and an image reproduction processing unit to reproduce an image by use of a result of the interpolation processing selected by the curvature determination unit, wherein the curvature determination unit selects a point A, a point B, and a point C of discrete data adjacently arranged in a predetermined direction near the target area, and determines the first curvature based on a distance f.sub.1R between a point externally dividing a line segment connecting the point A and the point B at (AB+BC):BC and the point C (where AB is a distance between the point A and the point B, and BC is a distance between the point B and the point C). Therefore, the amount of computation in calculating curvature from discrete data can be suppressed.
TEMPERATURE COMPENSATION METHOD FOR SAR SENSOR OF TERMINAL, AND TERMINAL
A temperature compensation method for a SAR sensor (3) of a terminal, and a terminal are disclosed. The terminal comprises: a temperature sensing unit (1), a processor (2), and an SAR sensor (3); the temperature sensing unit (1) is configured to send a first trigger signal to the processor (2) in response to detecting that a temperature change amount of the SAR sensor (3) exceeds a preset value; the processor (2) is configured to send a first temperature control signal to the SAR sensor (3) upon receiving the first trigger signal; and the SAR sensor (3) is configured to activate a second-order temperature compensation of the SAR sensor (3) according to the first temperature control signal, and the second-order temperature compensation compensates for baseline data of the SAR sensor (3) together with a first-order temperature compensation of the SAR sensor (3). Therefore, real-time tracking of the temperature change amount by the baseline data of the SAR sensor (3) can be ensured, and the problem in the terminal of false trigger of the SAR sensor (3) caused by drastic temperature change can be avoided.
SYNTHETIC APERTURE RADAR SIGNAL PROCESSING DEVICE
A synthetic aperture radar signal processing device according to the present invention includes, a low-accuracy interpolation processing unit to perform interpolation processing on discrete data obtained from signals received by a synthetic aperture radar, a high-accuracy interpolation processing unit to perform interpolation processing on the discrete data with higher accuracy than the low-accuracy interpolation processing unit, a curvature determination unit to select either the high-accuracy interpolation processing unit or the low-accuracy interpolation processing unit in accordance with a first curvature that is a curvature of the discrete data at a target area for the interpolation processing, and an image reproduction processing unit to reproduce an image by use of a result of the interpolation processing selected by the curvature determination unit, wherein the curvature determination unit selects a point A, a point B, and a point C of discrete data adjacently arranged in a predetermined direction near the target area, and determines the first curvature based on a distance f.sub.1R between a point externally dividing a line segment connecting the point A and the point B at (AB+BC):BC and the point C (where AB is a distance between the point A and the point B, and BC is a distance between the point B and the point C). Therefore, the amount of computation in calculating curvature from discrete data can be suppressed.
Synthetic aperture radar data compression and transmission
The present disclosure generally relates to techniques for processing complex-valued array data representing an image. The techniques may include obtaining an electronic representation of an array of complex numbers representing an image, converting the array of complex numbers to an array of scaled coordinate pair values in a magnitude-phase plane, replacing each coordinate pair value with data representing a respective nearest node in a quantized magnitude-phase plane, such that an array of scaled quantized coordinate value pairs is produced, arranging into a sequence of bit values ordered according to decreasing bit significance, from most-significant bit values to least-significant bit values, the scaled quantized coordinate value pairs, and transmitting the sequence of bit values to a receiver, such that the receiver rearranges and rescales the sequence of bit values and obtains the image represented by the array of complex numbers.
Thermal protection system including high temperature radio frequency aperture
A thermal protection system includes: an outer skin; a thermally insulating material under the outer skin; and a high temperature radio frequency (RF) aperture. The RF aperture includes a plurality of waveguides separated from each other and extending through the outer skin and the thermally insulating material.
Synthetic aperture radar simulation
Various embodiments of the present technology generally relate to systems, methods, and computer-readable media for simulating synthetic aperture radar (SAR) images to be captured by a radar-based imaging system. SAR technology can be used to capture large areas on Earth, from a satellite in space for example, over a single pass. A further pass over the target area can help identify changes in the landscape, scenery, and/or infrastructure providing insight on change detection, temporal analysis, or other measures; however, repeat passes over the target area may have been made from differing angles resulting in artifacts in one or both of the processed images from the two passes. In various embodiments, information about the topology of the target area, and information about the SAR platform's flight path are used to simulate the slant range distortion effects that are to be expected in the SAR image of for that pass.
STATE DETERMINATION DEVICE, STATE DETERMINATION METHOD, AND RECORDING MEDIUM HAVING STATE DETERMINATION PROGRAM STORED THEREON
A state determination device includes: an acquisition unit for analyzing observation information near the surface of the ground by a satellite-borne synthetic aperture radar (SAR) to acquire a state measurement value indicating a state near the surface of the ground; a determination unit for determining whether a relation between a value of an index with which predetermined regularity regarding the state may be present and the state measurement value or a relation between a state estimation value near the surface of the ground that is estimated from a value of the index and the state measurement value satisfies the predetermined regularity; and an output unit that when the relation between the value of the index and the state estimation value or the relation between the state estimation value and the state measurement value does not satisfy the predetermined regularity, outputs determination result information indicating that the state is abnormal.
Method and system for rendering a synthetic aperture radar image
The present disclosure relates to a method (100) for rendering a simulated Synthetic Aperture Radar, SAR, image. The method comprises providing (110) a digital surface model or the like comprising 3D coordinate data in a geo-referenced coordinate system, determining (120) a sub-section of the digital surface model, and obtaining (130) the simulated SAR image based on the subsection of the digital surface model, wherein substantially each point in the simulated SAR image being associated to a 3D coordinate in the geo-referenced coordinate system.
Phase center alignment for fixed repetition rate synthetic aperture systems
A system for adjusting phase centers of a receiving array in real time. In one embodiment, a transmitter transmits a sequence of pings. Receiving elements are grouped into staves and summed prior to subsequent processing, and the groups are selected so that the phase center on a ping is substantially in the same location as another phase center on a previous ping.
Method for suppressing azimuth ambiguity of multi-channel SAR systems based on channel cancellation
The present disclosure discloses a method for suppressing the azimuth ambiguity of multi-channel SAR systems based on channel cancellation, which falls within the field of radar signal processing. The method includes: imaging echoed of the multi-channel SAR system based on a linear mapping reconstruction algorithm to obtain a reconstructed high-resolution wide-swath image; estimating positions of the azimuth ambiguity regions of the reconstructed high-resolution wide-swath image; extracting ambiguity images in the azimuth ambiguity regions based on channel cancellation and the refocusing algorithm; and suppressing a repetitive ambiguity image in imaging the echo of the multi-channel SAR system. The method weakens the influence of the original image on azimuth ambiguity extraction, improves the performance of ambiguity suppression, and solves the problem of additional repetitive ambiguity in multi-channel SAR systems by reconstructing the ambiguity signal, and improves the image quality of the multi-channel SAR system, which has great value for subsequent applications such as SAR image interpretation.