- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Bistatic SAR: Forecasting Spatial Resolution
摘要： This paper derives closed form expressions for bistatic synthetic aperture radar spatial resolution of a generalized system from the k-space or the wavenumber domain. These spatial resolution equations have not previously appeared in the literature. From these equations, significant resolution is found in both range and cross-range forecasting a forward-scatter bistatic synthetic aperture radar image when the elevation angles of each bistatic platform are significantly different. Simulation and lab tests demonstrated the forward scatter resolution.
关键词： image resolution,synthetic aperture radar,radar remote sensing,spatial resolution,radar imaging,bistatic radar,microwave imaging
更新于2025-09-23 15:22:29
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[IEEE 2018 International Conference on Radar (RADAR) - Brisbane, Australia (2018.8.27-2018.8.31)] 2018 International Conference on Radar (RADAR) - High-Resolution Radar Imaging with Unknown Noise
摘要： This paper addresses the problem of high-resolution radar imaging in complex environments with unknown noise in a Bayesian framework. In the new statistical model, the noise obeys Gaussian mixture distribution, and the weights are governed by the sparsity-promoting Gamma-Gaussian hierarchical prior. Then, the weights are estimated via the maximum a posterior-expectation maximization (MAP-EM) technique. Experiments have shown that the proposed method provides an effective way of high-resolution radar imaging in complex environments such as barrage jamming.
关键词： Radar imaging,jamming suppression,Bayesian learning,MAP-EM,GMM
更新于2025-09-23 15:22:29
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[IEEE 2018 9th International Conference on Ultrawideband and Ultrashort Impulse Signals (UWBUSIS) - Odessa, Ukraine (2018.9.4-2018.9.7)] 2018 9th International Conference on Ultrawideband and Ultrashort Impulse Signals (UWBUSIS) - Active Aperture Synthesis Radar for High Spatial Resolution Imaging
摘要： To solve problems of high-precision mapping of spatially extended objects regardless of weather conditions and time of day, radar imaging systems are used. The globality and efficiency of the survey is provided by the placement of radars on aerospace carriers. At the same time, there has been a proliferation of side-scan radars (providing a wide viewing range with a low spatial resolution) and antenna aperture synthesis radars (these provide high resolution in spatial coordinates, which depends on the type of survey). Radars used for imaging are classified according to various characteristics determining their advantages and disadvantages. Among such features, we can also distinguish the radar viewing area, which is currently limited to angles of 15° to 60° to the right and left of the observation in the nadir. The viewing range from -15° to +15° from the nadir is characterized by a low resolution in range and traditionally is not visible by these radars (the so-called "blind zone"). In this regard, an alternative system for building radar images from aerospace carriers is proposed. It will provide imaging with high angular resolution of the viewing range from -15° to +15° from the nadir. The main feature of the developed radar lies in the signal processing algorithm that combines methods of active (the presence of probing UWB signal) and passive (aperture synthesis) radiolocation. In addition, the radar implements a new method of "spectral aperture synthesis," which allows from processing of UWB signals with the continuum spectrum to processing multi-band signal processing.
关键词： radar mapping,active aperture synthesis,aerospace systems of remote sensing,radar imaging methods
更新于2025-09-23 15:21:21
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Wide-Angle, Ultra-Wideband ISAR Imaging of Vehicles and Drones
摘要： In-situ, wide-angle, and ultra-wideband inverse synthetic aperture radar (ISAR) imaging of vehicles and drones is demonstrated using a portable ultra-wideband radar. In order to form well-focused ISAR images, motion compensation is performed before applying the k-space imaging algorithm. While the same basic motion compensation methodology is applied to both types of targets, a more complex motion model is needed to better capture the ?ight path of the drone. The resulting ISAR images clearly show the geometrical outline of the targets and highlight locations of prominent backscattering. The ISAR images are also assessed against images generated through instrumented targets or laboratory measurements, and the image quality is shown to be comparable.
关键词： ultra-wideband,radar imaging,vehicles,radar measurements,drones,inverse synthetic aperture radar
更新于2025-09-23 15:21:01
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New Perspectives in Breast Imaging || Near-Field Radar Microwave Imaging as an Add-on Modality to Mammography
摘要： According to global statistics, there is a high incidence of cancer in western countries; and, due to the limited resources available in most healthcare systems, it seems like one of the most feasible options to fight against cancer might be strict prevention policies—such as eliminating carcinogens in people’s daily lives. Nevertheless, early cancer detection and effective treatment are still necessary, and understanding their efficacy and limitations are important issues that need to be addressed in order to ultimately enhance patients’ survival rate. In the case of breast cancer, some of the problems faced by conventional mammography have been addressed in the literature; they include high rate of false-positive and false-negative results, as well as the possibility of overdiagnosis. New technologies, such as digital breast tomosynthesis (DBT), have been able to improve the sensitivity and specificity by using 3D imaging. However, the low contrast (1%) existing between tumors and healthy fibroglandular tissue at X-ray frequencies has been identified as one of the main causes of misdiagnosis in both conventional 2D mammography and DBT. Near-field radar imaging (NRI) provides a unique opportunity to overcome this problem, since the contrast existing between the aforementioned tissues is intrinsically higher (10%) at microwave frequencies. Moreover, the low resolution and highly complex scattering patterns of microwave systems can be enhanced by using prior information from other modalities, such as the DBT. Therefore, a multimodal DBT/NRI imaging system is proposed to exploit their individual strengths while minimizing their weaknesses. In this work, the foundation of this idea is reviewed, and a preliminary design and experimental validation of the NRI system, used as a DBT complement, is introduced.
关键词： breast cancer statistics,digital breast tomosynthesis,microwave imaging,antipodal Vivaldi antennas,near-field radar imaging,breast cancer detection
更新于2025-09-23 15:21:01
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Broadband Cognitive Radio Enabled by Photonics
摘要： Cognitive radio is considered as a possible disruptive force to improve the spectral resource efficiency through sensing and interacting with the environment. Traditional electrical technologies to implement the cognitive radio face challenges in terms of bandwidth, resolution, and speed. In this paper, the concept and architecture of broadband cognitive radio systems enabled by photonics are proposed. Key microwave photonic techniques for the architecture are reviewed, including the photonics-based spectrum sensing, the photonic arbitrary waveform generation, the photonics-based self-interference cancellation processing, and the microwave photonic dechirp processing and radar imaging. A preliminary demonstration of a cognitive radar system enabled by photonics is performed. The future possible research directions on this topic are discussed.
关键词： Cognitive radio,spectrum sensing,microwave photonics,radar imaging,self-interference cancellation,waveform generation
更新于2025-09-23 15:21:01
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Optical Fiber Communications (Principles and Applications) || Radio over Fiber
摘要： Radio over Fiber (RoF) technology can integrate advantages of both wireless networks and optical fiber networks. Recently RoF technology has found numerous applications in broadband wireless access communication networks, radio astronomy, RADAR and millimeter-wave communications, antenna array beam-forming, establishment of up- and down-converting links using photonic signals, spectroscopy, imaging, and electronic warfare.
关键词： wireless networks,RoF,radio astronomy,optical fiber networks,millimeter-wave communications,antenna array beam-forming,photonic signals,broadband wireless access,electronic warfare,Radio over Fiber,spectroscopy,RADAR,imaging
更新于2025-09-12 10:27:22
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Point-Spread-Function (PSF) Characterization of a 340 GHz Imaging Radar using Acoustic Levitation
摘要： In this paper, resolution characterization and beam analysis of a 340 GHz imaging radar are demonstrated by means of a point-spread-function imaging an acoustically levitated point-like target. It is shown that at THz frequencies, conventional PSF measurement techniques are limited by the presence of strong scattering response of background objects, such as suspension threads, within the imaging field-of-view (FOV). Using acoustic levitation, it is possible to eliminate secondary objects within the FOV and achieve a pure PSF characterization of the radar. It is shown that the PSF patterns obtained using acoustic levitation exhibit high fidelity and are free from artifacts. We demonstrate this using a small water droplet suspended in air at the focus of the 340 GHz radar. The measured PSF characteristics of the radar are in excellent agreement with physical optics (PO) simulations and analytical results.
关键词： acoustic levitation,submillimeter,antenna,beam,point-spread-function (PSF),Radar,imaging,acoustics
更新于2025-09-11 14:15:04
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - IBIS-ArcSAR: an Innovative Ground-Based SAR System for Slope Monitoring
摘要： In the last decade Ground-Based SAR (GB-SAR) technology has been demonstrated to be one of the most efficient tool for slope monitoring in open pit mines scenarios. However, especially for open pit mines application, one of the relevant limits is the azimuth coverage, being the mine often of elliptical shape. In this context, the IBIS-FM product of IDS GeoRadar company can reach about 80° of horizontal coverage, and can be overcome by IBIS-Rover product that can reach 270° of horizontal coverage but increasing the acquisition time. The recent IBIS-ArcSAR product developed by IDS GeoRadar can overcome these limits, offering a full 360° of horizontal coverage in less than 1 minute of acquisition time, with additional feature of a constant angular resolution. Moreover, by exploiting the new capability of MIMO (Multiple Input Multiple Output) Radar channels, the vertical height or Digital Elevation Model (DEM) of the mine can be reconstructed through simple and computationally fast interferometric processing algorithms, together with an enhanced focusing of 2D SAR Image that is an open issue in Arc-scanning SAR systems.
关键词： Interferometry,Ground-based Synthetic Aperture Radar,Digital Elevation Models,MIMO Radar,Radar Imaging
更新于2025-09-10 09:29:36
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Research Into Sar Imaging of Moving Ship Target Based on Isar Technology
摘要： The ship targets affected by sea conditions and other environment factors have complex non-cooperation movement, which cause serious defocusing phenomena in high resolution space-borne SAR images. In this paper, a novel ISAR-based imaging algorithm for moving ship target is presented. Firstly, the spatial geometric model of space-borne SAR is given, and the motorial characteristics of moving ship target are analyzed. Then, a novel imaging algorithm is derived, where the range alignment is solved by minimum information entropy criterion, and the accurate focusing is achieved through inverse SAR (ISAR) processing. Experiments based on the simulation and real data of TerraSAR-X are performed to validate the presented algorithm.
关键词： Motion compensation,Inverse Synthetic Aperture Radar(ISAR),Radar imaging,Minimum entropy,Moving Ship Target
更新于2025-09-10 09:29:36