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- 摘要
- 关键词
- 实验方案
- 产品
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[IEEE 2018 XXIIIrd International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory (DIPED) - Tbilisi, Georgia (2018.9.24-2018.9.27)] 2018 XXIIIrd International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory (DIPED) - GPR Image Focusing Using Matched Filter Algorithm
摘要： In this study a synthetic aperture radar-based reconstruction technique is applied to focus the unwanted disruptive effects in the two-dimensional ground penetrating radar data. The formulation of the applied Matched Filter Algorithm (MFA) which completely removes the hyperbolic effects is presented in detail. To test the capability of the proposed technique an experimental measurement setup is constructed in the laboratory and MFA is operated to gathered real GPR data. Thanks to the applied technique, high-resolution focused B-Scan GPR images are successfully obtained.
关键词： Ground penetrating radar(GPR),synthetic aperture radar(SAR),matched filter algorithm(MFA)
更新于2025-09-09 09:28:46
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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 - Doppler Ambiguities Masking for Altimeter Waveforms: a Model Based Approach
摘要： Delay/Doppler processing for radar altimeters allows to improve the along-track resolution, but it can be affected by Doppler ambiguities depending on the design of the instrument. If not accounted for, Doppler ambiguities can cause a distortion of the multilooked waveforms and a loss of accuracy in retrieved geophysical parameters. This paper presents a waveform model based approach to define a Doppler ambiguity mask to filter out the samples affected by the ambiguous returns before multilooking, assuming a uniform rough scattering surface. The effectiveness of the proposed method for Doppler ambiguities masking has been verified on Sentinel-6 simulated data and on in-orbit data from CryoSat SAR in acquisitions over ocean.
关键词： CryoSat,Doppler ambiguities,Sentinel-6,Synthetic Aperture Radar,Radar Altimeter
更新于2025-09-09 09:28:46
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REGULARIZATION IMAGING ALGORITHM WITH ACCURATE G MATRIX FOR NEAR-FIELD MMW SYNTHETIC APERTURE IMAGING RADIOMETER
摘要： In order to improve the reconstruction accuracy of near-?eld SAIR, a novel regularization imaging algorithm based on an accurate G matrix is proposed in this paper. Due to the fact that the regularization reconstruction is usually an underdetermined problem, inaccurate operation matrix G will lead to great reconstruction error in the imaging results, or even the normal imaging cannot be obtained. In this paper, we establish an accurate G matrix based on the accurate imaging model of near-?eld SAIR. Compared with the traditional G matrix with some unnecessary approximations, the proposed G matrix without approximation can improve the reconstruction accuracy e?ectively. For improving the accuracy of matrix G further, the corresponding parameters are corrected according to the RMSE between the imaging results of the regularization method and modi?ed FFT method which is not sensitive to the parameters’ change. The e?ectiveness of this calibration method has been tested by 1D simulation experiments. Moreover, the 2D simulation experiments demonstrate that the proposed accurate G matrix can improve the imaging accuracy of regularization method e?ectively. Finally, the 1D imaging experiment is performed to test the e?ectiveness of the proposed method for the actual synthetic aperture imaging further.
关键词： near-field MMW synthetic aperture imaging radiometer,Regularization imaging algorithm,accurate G matrix,reconstruction accuracy
更新于2025-09-09 09:28:46
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APPLICATION OF FACET SCATTERING MODEL IN SAR IMAGING OF SEA SURFACE WAVES WITH KELVIN WAKE
摘要： The principal purpose of this work is the simulation of the ship wake in Synthetic Aperture Radar (SAR) imaging based on a facet scattering model. The hydrodynamic model of the surface waves mainly considers the Kelvin wake waves and the wind driven waves. For the prediction of radar returns from the composite surface, the semi-deterministic facet scattering model (SDFSM) is proposed, which is veri?ed to have good performance through a comparison with the experiment by SASS-II. Then, the distributions of backscattering normalized radar cross section (NRCS) of facets are investigated for both V V and HH polarizations and characteristics of the wake pattern are shown with good visibility. On the basis of these, an application of velocity bunching (VB) imaging model is presented in detail for the simulation of SAR imaging of sea surface waves with Kelvin wake. Finally, several numerical results provide states of the e?ects of ship speed, wind speed and the ship sailing direction on the characteristics of Kelvin wake in SAR images. Thus, this simulation may enable us to provide a theoretical basis to the detection of ship wakes.
关键词： Kelvin wake,facet scattering model,velocity bunching (VB) imaging model,Synthetic Aperture Radar (SAR),ship detection
更新于2025-09-09 09:28:46
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[IEEE 2018 48th European Microwave Conference (EuMC) - Madrid, Spain (2018.9.23-2018.9.27)] 2018 48th European Microwave Conference (EuMC) - High Quality <tex>$\mathrm{TE}_{011}$</tex> Mode Cavity Filter for Input Multiplexer Applications
摘要： This paper presents a novel resonator realized by chamfering the edges of a square cavity, and the high quality factor (Q) TE011 mode can be separate from its degenerate TM111 mode. Detailed analysis of the coupling mechanisms among the resonators is demonstrated, which can conveniently achieve complicated transfer functions. Based on the typical specification of Ka-band input multiplexer (IMUX), two channel filters utilizing the novel resonator are designed and fabricated with 60MHz bandwidth centers on 20GHz and 20.3GHz respectively. The measured responses show excellent agreement with the simulation. Average realizable unloaded Q of 10500 can be achieved.
关键词： U-shaped aperture,TE011 mode,input multiplexer,mode control
更新于2025-09-09 09:28:46
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Translate SAR Data into Optical Image Using IHS and Wavelet Transform Integrated Fusion
摘要： Although synthetic aperture radar (SAR) sensors function well at all times and under all weather conditions, the images they produce are not intuitively straightforward. A novel idea based on data fusion is introduced to translate SAR data into optical image in this paper. The proposed SAR-optical image translation is implemented using an intensity–hue–saturation (IHS) and wavelet transform integrated fusion (IHSW), so as to preserve as much as spatial details from SAR data, and minimize the spectral distortion of translated output. COSMO-SkyMed and ENVISAT-ASAR images are translated into optical images with the fusion of Landsat TM images, and the fusion results are compared with some conventional fusion methods, as well as the texture synthesis approach. Quality assessment of different fused outputs is carried out by using six quality indices. Visual and statistical comparisons of the ?nal results indicate that the proposed approach achieves an effective translation from SAR to optical image and is superior to texture synthesis-based algorithm in terms of preserving spatial and spectral information. The proposed translation technique presents an alternative to improve the interpretability of SAR images.
关键词： Image fusion,Synthetic aperture radar (SAR),Image translation,Wavelet transform
更新于2025-09-09 09:28:46
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Cavity model-based analysis of field propagation in a six-port Riblet-type directional coupler
摘要： A cavity model-based analysis of electric field propagation inside a six-port Riblet-type directional coupler has been presented in this paper. Though cavity modeling technique is not very new and was previously applied to different rectangular waveguide-based passive networks to find their network parameters, for the first time it has been used here to analyze the field propagation inside a six-port Riblet-type directional coupler. From the analysis, the frequency response of the network has been estimated. Since the main objective of this work is to analyze the field propagation inside a passive network, not to present another network, a six-port Riblet-type directional coupler that is already proposed in literature has been considered. The numerical analysis has been verified by comparing the scattering parameters data obtained from the cavity model analysis with CST Microwave Studio simulation data and measured data available in the literature.
关键词： Riblet-type directional coupler,cavity modeling technique,Aperture field distribution,method of moment,scattering parameters
更新于2025-09-09 09:28:46
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[IEEE 2018 XIV International Scientific-Technical Conference on Actual Problems of Electronics Instrument Engineering (APEIE) - Novosibirsk, Russia (2018.10.2-2018.10.6)] 2018 XIV International Scientific-Technical Conference on Actual Problems of Electronics Instrument Engineering (APEIE) - Modern Tendencies in the Development of Airborne Synthesized Aperture Radars for Remote Sensing of the Earth
摘要： The article is an overview of the development trends of aviation synthetic aperture radars, including information on new systems created in the world and Russia. It describes main technical features of the prospective radar and tasks to be solved for them.
关键词： unmanned aerial vehicle,remote sensing,light aircraft,airborne micro navigation system,Synthetic aperture radar,high resolution radar
更新于2025-09-09 09:28:46
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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 - Development of an Approach for Monitoring Sugarcane Harvested and Non-Harvested Conditions Using Time Series Sentinel-1 Data
摘要： With the recent launch of Sentinel-1 constellations and frequent availability of C-band synthetic aperture radar (SAR) data at no cost, there is an opportunity to monitor crops on regular basis, which is still not explored. Therefore, in this paper an approach has been proposed to monitor sugarcane harvest status using time series Sentinel-1 data. The proposed approach uses knowledge based classification and temporal profile for obtaining harvest status of crops. The approach is able to identify harvested and non-harvested sugarcane areas from other crops with an overall accuracy of 82.17%.
关键词： sugarcane,time series analysis,Sentinel-1,Synthetic Aperture Radar (SAR)
更新于2025-09-09 09:28:46
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Compressed sensing reconstruction of synthetic transmit aperture dataset for volumetric diverging wave imaging
摘要： A high volume rate and high performance ultrasound imaging method based on a matrix array is proposed by using compressed sensing (CS) to reconstruct the complete dataset of synthetic transmit aperture (STA) from three-dimensional (3D) diverging wave transmissions (i.e., 3D CS-STA). Hereto, a series of apodized 3D diverging waves are transmitted from a fixed virtual source, with the ith row of a Hadamard matrix taken as the apodization coefficients in the ith transmit event. Then CS is used to reconstruct the complete dataset, based on the linear relationship between the backscattered echoes and the complete dataset of 3D STA. Finally, standard STA beamforming is applied on the reconstructed complete dataset to obtain the volumetric image. Four layouts of element numbering for apodizations and transmit numbers of 16, 32, and 64 are investigated through computer simulations and phantom experiments. Furthermore, the proposed 3D CS-STA setups are compared with 3D single-line-transmit (SLT) and 3D diverging wave compounding (DWC). The results show that, i) 3D CS-STA has competitive lateral resolutions to 3D STA, and their contrast ratios (CRs) and contrast-to-noise ratios (CNRs) approach to those of 3D STA as the number of transmit events increases in noise-free condition. ii) the tested 3D CS-STA setups show good robustness in complete dataset reconstruction in the presence of different levels of noise. iii) 3D CS-STA outperforms 3D SLT and 3D DWC. More specifically, the 3D CS-STA setup with 64 transmit events and the Random layout achieves ~31% improvement in lateral resolution, ~14% improvement in ratio of the estimated-to-true cystic areas, a higher volume rate, and competitive CR/CNR when compared with 3D DWC. The results demonstrate that 3D CS-STA has great potential of providing high quality volumetric image with a higher volume rate.
关键词： compressed sensing,synthetic transmit aperture,volumetric diverging wave imaging,matrix array,ultrasound imaging
更新于2025-09-09 09:28:46