- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Spatial-Based Chipless RFID System
摘要： Conventional techniques in chipless RFID systems are incapable of fully overcoming the key challenges of modern identification applications, including high data capacity, low tag cost and reliable operation. The idea of electromagnetic (EM) imaging in chipless RFID systems is a promising technique that shows many advantages over other conventional approaches. This paper reviews conventional chipless RFID technology and provides a comprehensive analysis of advanced millimeter wave spatial-based (also known as image-based) chipless RFID systems with an optimized MIMO-SAR technique for high-resolution image acquisition and a quick reading process.
关键词： Multiple-input multiple-output (MIMO),Millimeter wave (mmwave),Chipless radio frequency identification (RFID),EM imaging,Virtual antenna array,Synthetic aperture radar (SAR)
更新于2025-09-23 15:22:29
-
Improved Method of Video Synthetic Aperture Radar Imaging Algorithm
摘要： Video synthetic aperture radar (ViSAR) is a novel imaging model to persistently surveil the region of interest by a series of consecutive images in real time. The formation time of one frame image, which can influence the image latency, is one of the key factors to realize ViSAR system. In general, the polar format algorithm (PFA) is preferred for ViSAR imaging. However, the 2-D resampling in the PFA has a large computation burden and is complex to realize in the real-time processing system. It has become the main obstacle to reduce image latency. Therefore, we derive four judgment criteria in this letter. According to these criteria, we propose the improved method of the PFA. Based on this method, the modified PFA can reduce the image formation time while guaranteeing the image quality. Simulation results are presented to validate the effectiveness of the improved method proposed in this letter.
关键词： judgment criteria,Improved method,video synthetic aperture radar (ViSAR),polar format algorithm (PFA)
更新于2025-09-23 15:22:29
-
A new CFAR algorithm based on variable window for ship target detection in SAR images
摘要： Target detection in the multiscale situation where there exit multiple ship targets with different sizes is a challenging task due to the mismatch of the sizes of ship targets and fixed windows. A new constant false alarm rate (CFAR) algorithm based on variable window for ship target detection in SAR images is proposed. First, the multiscale local contrast measure is introduced to estimate the ship target size without any prior knowledge about ships. Second, the size of neighborhood area is adaptively set and a transform algorithm is designed to enhance the contrast between targets and background. Finally, CFAR detection is implemented by adopting variable window to gain the accurate ship targets. Experimental results indicate that the proposed algorithm has better performance compared with other CFAR detection algorithms.
关键词： Constant false alarm rate (CFAR),Ship target detection,Variable window,Synthetic aperture radar (SAR)
更新于2025-09-23 15:22:29
-
[IEEE 2018 IEEE 3rd International Conference on Signal and Image Processing (ICSIP) - Shenzhen, China (2018.7.13-2018.7.15)] 2018 IEEE 3rd International Conference on Signal and Image Processing (ICSIP) - Review of Research on Registration of SAR and Optical Remote Sensing Image Based on Feature
摘要： Synthetic Aperture Radar(SAR) and optical remote sensing image registration is the prerequisite for image fusion and it is of important theoretical significance and practical value. The image registration methods are mainly divided into the methods based on feature, the methods based on Gray-scale and others. This article systematically sorts out feature-based optical and SAR remote sensing image registration techniques, summarizes all types of image registration, points out their advantages and disadvantages and predicts the prospects of their future.
关键词： synthetic aperture radar(SAR),image registration,remote sensing,feature-based
更新于2025-09-23 15:22:29
-
Phasor Quaternion Neural Networks for Singular Point Compensation in Polarimetric-Interferometric Synthetic Aperture Radar
摘要： Interferograms obtained by synthetic aperture radar often include many singular points (SPs), which makes it difficult to generate an accurate digital elevation model. This paper proposes a filtering method to compensate SPs adaptively by using polarization and phase information around the SPs. Phase value is essentially related to polarization changes in scattering as well as propagation. In order to handle the polarization and phase information simultaneously in a consistent manner, we define a new number, phasor quaternion (PQ), by combining quaternion and complex amplitude, with which we construct the theory of PQ neural networks (PQNNs). Experiments demonstrate that the proposed PQNN filter compensates SPs very effectively. Even in the situations where the conventional methods deteriorate in their performance, it realizes accurate compensation, thanks to its good generalization characteristics in integrated Poincare-sphere polarization space and the complex-amplitude space. We find that PQNN is an excellent framework to deal with the polarization and phase of electromagnetic wave adaptively and consistently.
关键词： Complex-valued neural network (CVNN),phase singular point,polarimetric interferometric synthetic aperture radar (PolInSAR),quaternion neural network (QNN),digital elevation model (DEM)
更新于2025-09-23 15:22:29
-
[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - An Tensor-Based Corn Mapping Scheme with Radarsat-2 Fully Polarimetric Images
摘要： As one of the most essential economic and industrial crops globally, corn holds a very important position in China’s agricultural industry. Corn mapping is one of the most concerned fields in agricultural surveillance. However, compared with the utilization of backscattering coefficients, the polarimetric information was not fully discussed in previous corn mapping researches. In this paper, we use the coherency matrix of mid to late term multi-temporal fully polarimetric synthetic aperture radar (FP SAR) data to discriminate corn cultivation areas. The tensor representation is adopted for PolSAR analysis, with the help of multilinear principal component analysis (MPCA) to reduce feature dimensions. The importance of polarimetric information is discussed. This paper illustrates that good corn discrimination could be achieved with only mid to late term FP SAR data.
关键词： corn mapping,synthetic aperture radar (SAR),decision tree,multi-temporal SAR,multilinear principal component analysis (MPCA),polarimetric SAR (PolSAR)
更新于2025-09-23 15:22:29
-
[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - The Recovery Algorithm of Saturated Sar Raw Data Based on Compressed Sensing
摘要： Because of the unprediction of the scene scattering characteristic and the finite quantization bits, saturated data always exists. Saturation phenomenon leads to a non-linear distortion and interferes to the recognition of the target so that it affects the image quality. Especially when the scene scattering characteristic largely varies, it can generate false targets and degrade signal-to-noise ratio (SNR). Compressed sensing (CS), a non-linear reconstructed algorithm, is that samples in sub-Nyquist rate is used to recover the sparse signal with few non-zero elements. This paper proposes the recovery method based on the non-linear characteristic of CS to recover the saturated part of the raw data to the unsaturation state and ensure the unsaturated parts maintain the original state. Simulation results validate the proposed method.
关键词： non-linear,compressed sensing,SAR raw data,saturation,Synthetic aperture radar
更新于2025-09-23 15:22:29
-
[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Analysis of NsRCM in BiForSAR Imagery
摘要： As for the bistatic forward-looking synthetic aperture radar (BiForSAR) imaging, frequency-domain imaging algorithms integrated with autofocus is advisable to get a well focused BiForSAR image in the presence of uncompensated motion errors. Nevertheless, a severe drawback of the autofocus algorithms is that they are only capable of removing one-dimensional azimuth phase errors. In range direction, there exists nonsystematic range cell migration (NsRCM) originated from motion errors and RCM correction procedure in frequency domain imaging algorithms as well. In this paper, the causes of different NsRCM in BiForSAR imaging are analyzed, and the corresponding relationship between different NsRCM is deduced. Based on the analyses, we propose an autofocus NsRCM correction scheme for BiForSAR imagery using frequency domain imaging algorithms, being capable of eliminating the range-dependent NsRCM.
关键词： Bistatic Forward-looking Synthetic Aperture Radar (BiForSAR),autofocus,nonsystematic range cell migration (NsRCM),minimum-entropy,spatially-variant
更新于2025-09-23 15:22:29
-
[IEEE 2018 China International SAR Symposium (CISS) - Shanghai (2018.10.10-2018.10.12)] 2018 China International SAR Symposium (CISS) - Extended Map-Drift Algorithm for Spaceborne Sliding Spotlight SAR Data
摘要： For flexibly steering antenna in along-track direction, space-borne synthetic aperture radar (SAR) can achieve high resolution with wide swath conveniently, especially in sliding spotlight mode. In order to overcome azimuth folding effects in this mode, the three-step focusing algorithm was been proposed. However it is difficult to perform fine focus of image due to Doppler rate errors. In this paper, a kind of auto-focusing approach based on Map-Drift (MD) is proposed, which is compatible with the three-step imaging algorithm and efficient. Firstly, the Doppler-rate error transfer mechanism in de-ramp operation (the third step of the three-step focusing algorithm) is illustrated. Secondly, the accurate images draft due to Doppler-rate error is conduced based on this mechanism. Thirdly, a new efficient strategy of iteration is present. Finally, the validness and efficiency of the proposed approach is tested by simulation data and real SAR data.
关键词： synthetic aperture radar (SAR),Map-Drift,auto-focusing,sliding spotlight,focusing algorithm,three-step approach
更新于2025-09-23 15:22:29
-
[IEEE 2018 China International SAR Symposium (CISS) - Shanghai (2018.10.10-2018.10.12)] 2018 China International SAR Symposium (CISS) - Velocity Estimation for Moving Target Refocusing in the Long-Time Coherent Integration SAR Imaging
摘要： A novel procedure is proposed to estimate the two-dimensional (2-D) velocity parameters of moving targets from single-channel synthetic aperture radar (SAR) data in a long-time coherent integration for motion compensation. First, the SAR data is divided into several sub-band data by sub-aperture decomposition, since target motion may be changing in the whole long-time aperture, so that the velocity estimation for each sub-band can be performed respectively. Then, the range walk correction is carried out via Doppler centroid analysis based motion estimation and compensation, by which the energy of the moving target is concentrated into a single range cell. This processing is especially advantageous to the following exact Doppler parameter estimation. Finally, the fine 2-D motion parameters are estimated based on mismatched compression simultaneously. Compared to conventional algorithms with a time-consuming searching process, the 2-D velocity estimation of moving targets can be carried out using this algorithm more efficiently, and the SAR image can be well focused and right located after further motion compensation. Experimental results for numerically simulated SAR images demonstrate the effectiveness of the proposed technique.
关键词： doppler centroid analysis,synthetic aperture radar (SAR),refocusing,mismatched compression,velocity estimation
更新于2025-09-23 15:22:29