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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Can Photovoltaic Plants Cause Voltage Flicker? a?? Field Measurement and Screening
摘要： Along-track multichannel synthetic aperture radar is usually used to achieve ground moving target detection and imaging. Nevertheless, there is a design dilemma between azimuth high resolution and wide swath (HRWS). To solve this problem in HRWS mode, we introduce a virtual multichannel (VMC) scheme. For each virtual channel, the low real pulse repetition frequency (PRF) improves the ability of resolving range ambiguity for wide-swath, and the high virtual PRF improves the capability of resolving Doppler ambiguity for azimuth high resolution. For multiple virtual channels, strong ground clutter is eliminated by the joint VMC processing. Furthermore, a detailed signal model of a moving target in the virtual channel is given, and the special false-peak effect in the azimuthal image is analyzed. Moreover, we propose a novel ground moving target processing method based on the VMC scheme and the clutter suppression interferometry (CSI) technique, which is called VMC-CSI. The integration of detection, location, velocity estimation, and imaging for ground moving targets can be achieved. Accounting for the unresolved main peak and false peak for a moving target, in the VMC-CSI method, we adopt a two-step scheme to estimate the radial velocity and along-track velocity, namely, rough estimation and precise estimation. Meanwhile, considering the same interferometric phases of the main peak and the false peak, we use false peaks first for the robustness of initial azimuth location estimation and remove false peaks afterward. Numerical simulations are provided for testing the effect of the false peak and the effectiveness of VMC-CSI.
关键词： high resolution and wide swath (HRWS),multichannel synthetic aperture radar (SAR),Ground moving target,virtual channel,SAR
更新于2025-09-23 15:19:57
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Numerical study of comb-based high-accuracy distance measurement utilizing VIPA interferometry
摘要： The ultrahigh-precision distance measurement based on a single laser frequency comb as the multi-wavelength source together with an ultra-high-resolution dispersive spectrometer utilizing a virtually imaged phase array (VIPA) was studied numerically. The simulations provide the component parameter optimization and the comb spectral images on a CCD camera. An ameliorated scheme was proposed through achieving real-time comparisons between the reference and interference signals captured on a camera simultaneously to improve both the measurement accuracy and the precision signi?cantly. With the optimized data processing, the proposed approach is especially suitable for serving as a ultra-high precision relative distance measurement, and the measurement resolution can reach picometer scale in the optimal cases.
关键词： Ultra-high precision distance measurement,Ultra-high resolution spectroscopy,Laser frequency comb,Virtually imaged phase array interferometry
更新于2025-09-19 17:15:36
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Unsupervised evaluation-based region merging for high resolution remote sensing image segmentation
摘要： Image segmentation has a remarkable influence on the classification accuracy of object-based image analysis. Accordingly, how to raise the performance of remote sensing image segmentation is a key issue. However, this is challenging, primarily because it is difficult to avoid over-segmentation errors (OSE) and under-segmentation errors (USE). To solve this problem, this article presents a new segmentation technique by fusing a region merging method with an unsupervised segmentation evaluation technique called under- and over-segmentation aware (UOA), which is improved by using edge information. Edge information is also used to construct the merging criterion of the proposed approach. To validate the new segmentation scheme, five scenes of high resolution images acquired by Gaofen-2 and Ziyuan-3 multispectral sensors are chosen for the experiment. Quantitative evaluation metrics are employed in the experiment. Results indicate that the proposed algorithm obtains the lowest total error (TE) values for all test images (0.3791, 0.1434, 0.7601, 0.7569, 0.3169 for the first, second, third, fourth, fifth image, respectively; these values are averagely 0.1139 lower than the counterparts of the other methods), as compared to six state-of-the-art region merging-based segmentation approaches, including hybrid region merging, hierarchical segmentation, scale-variable region merging, size-constrained region merging with edge penalty, region merging guided by priority, and region merging combined with the original UOA. Moreover, the performance of the proposed method is better for artificial-object-dominant scenes than the ones mainly covering natural geo-objects.
关键词： region merging,high resolution remote sensing image,image segmentation,over- and under-segmentation aware,unsupervised evaluation
更新于2025-09-19 17:15:36
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Another look on region merging procedure from seed region shift for high-resolution remote sensing image segmentation
摘要： Region merging method is widely used for remote sensing image segmentation in Geographic Object-Based Image Analysis (GEOBIA) because of its simplicity and effectiveness. Instead of improving the merging strategy, similarity measure, and stopping rule for region merging method as usual, we aim at exploring the effectiveness of the seed region shift on region merging-based segmentation. Different region merging procedures with different seed region shift frequencies are compared by fixing other conditions, demonstrating that the shift of seed regions serves as one of the key impacts to segmentation accuracy for region merging method. If the seed regions keep fixed during region merging procedure, it will lead to uneven expansion of regions and consequently low segmentation accuracy. However, if the seed regions can be dynamically shifted during region merging procedure, it will lead to even expansion of regions and achieve similar segmentation performance for different region merging strategies. The findings could be beneficial to selecting or further improving image segmentation method for GEOBIA.
关键词： High-resolution remote sensing,Geographic object-based image analysis,Region merging,Seed region,Image segmentation
更新于2025-09-19 17:15:36
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[IEEE 2018 IEEE International Symposium on the Physical and Failure Analysis of Integrated Circuits (IPFA) - Singapore (2018.7.16-2018.7.19)] 2018 IEEE International Symposium on the Physical and Failure Analysis of Integrated Circuits (IPFA) - Application of Si Plasmon Imaging in Semiconductor Failure Analysis
摘要： In this paper, we demonstrate the various applications of the ETEM Si plasmon imaging technique in semiconductor failure analysis. The mechanism of the plasmon imaging will be discussed briefly, then followed by four case studies. The capability of Si plasmon imaging to distinguish the silicon oxide (e.g. gate oxide) and the silicon materials (e.g. poly gate and substrate) is its key advantage over the conventional imaging techniques. Si plasmon imaging not only can identify the defective residues but also can be performed at high magnification to investigate the gate oxide and its interfaces with poly or substrate.
关键词： Silicon plasmon imaging,energy filtered TEM,high resolution TEM
更新于2025-09-19 17:15:36
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Design of New Wavelet Packets Adapted to High-Resolution SAR Images With an Application to Target Detection
摘要： High resolution in synthetic aperture radar (SAR) leads to new physical characterizations of scatterers which are anisotropic and dispersive. These behaviors present an interesting source of diversity for target detection schemes. Unfortunately, such characteristics have been integrated and have been naturally lost in monovariate single-look SAR images. Modeling this lost behavior as nonstationarity, wavelet analysis has been successful in retrieving this information. However, the sharp-edge of the used wavelet functions introduces undesired high side-lobes for the strong scatterers present in the images. In this paper, a new family of parameterized wavelets, designed specifically to reduce those side lobes in the SAR image decomposition, is proposed. Target detection schemes are then explored using this spectro-angular diversity and it can be shown that in high-resolution SAR images, the non-Gaussian and robust framework leads to better results.
关键词： wavelet packets,High resolution,robust adaptive detection,synthetic aperture radar (SAR)
更新于2025-09-19 17:15:36
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Assessment of Segmentation Parameters for Object-Based Land Cover Classification Using Color-Infrared Imagery
摘要： Using object-based image analysis (OBIA) techniques for land use-land cover classification (LULC) has become an area of interest due to the availability of high-resolution data and segmentation methods. Multi-resolution segmentation in particular, statistically seen as the most used algorithm, is able to produce non-identical segmentations depending on the required parameters. The total effect of segmentation parameters on the classification accuracy of high-resolution imagery is still an open question, though some studies were implemented to define the optimum segmentation parameters. However, recent studies have not properly considered the parameters and their consequences on LULC accuracy. The main objective of this study is to assess OBIA segmentation and classification accuracy according to the segmentation parameters using different overlap ratios during image object sampling for a predetermined scale. With this aim, we analyzed and compared (a) high-resolution color-infrared aerial images of a newly-developed urban area including different land use types; (b) combinations of multi-resolution segmentation with different shape, color, compactness, bands, and band-weights; and (c) accuracies of classifications based on varied segmentations. The results of various parameters in the study showed an explicit correlation between segmentation accuracies and classification accuracies. The effect of changes in segmentation parameters using different sample selection methods for five main LULC types was studied. Specifically, moderate shape and compactness values provided more consistency than lower and higher values; also, band weighting demonstrated substantial results due to the chosen bands. Differences in the variable importance of the classifications and changes in LULC maps were also explained.
关键词： accuracy,infrared,segmentation,object-based classification,orthophoto,high resolution imagery,land cover
更新于2025-09-19 17:15:36
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Visualising the Cardiovascular System of Embryos of Biomedical Model Organisms with High Resolution Episcopic Microscopy (HREM)
摘要： The article will briefly introduce the high-resolution episcopic microscopy (HREM) technique and will focus on its potential for researching cardiovascular development and remodelling in embryos of biomedical model organisms. It will demonstrate the capacity of HREM for analysing the cardiovascular system of normally developed and genetically or experimentally malformed zebrafish, frog, chick and mouse embryos in the context of the whole specimen and will exemplarily show the possibilities HREM offers for comprehensive visualisation of the vasculature of adult human skin. Finally, it will provide examples of the successful application of HREM for identifying cardiovascular malformations in genetically altered mouse embryos produced in the deciphering the mechanisms of developmental disorders (DMDD) program.
关键词： episcopic,phenotyping,HREM,high resolution episcopic microscopy,chick,imaging,embryo,3D,developmental biology,mouse
更新于2025-09-19 17:15:36
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Improved integral equation method based on radiation distribution factors for high-resolution radiative intensity in graded index media
摘要： An improved integral equation method based on radiation distribution factors (RDFIEM) is developed to solve the radiative intensity with high directional resolution in semitransparent media with graded refractive index (GRI). The radiation distribution factors (RDFs) are solved by using the reverse Monte Carlo curved ray tracing technique (RMCCRT). Based on the RDFs, the source terms along the curved ray path decided by the Fermat principle are predicted accurately. Then, the integral equation method (IEM) is employed to solve the radiative intensity through integral along the curved ray path. One-dimensional and two-dimensional test cases are done, and all the results show that the RDFIEM is not only flexible in treating directional radiation problems but also very accurate and efficient.
关键词： Graded refractive index,Semitransparent media,High-resolution radiative intensity,RDFIEM
更新于2025-09-19 17:15:36
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Structural changes upon electronic excitation in 1,2-dimethoxybenzene from rotationally resolved electronic spectroscopy of various isotopologues
摘要： The structural changes of 1,2-dimethoxybenzene upon electronic excitation have been elucidated from a comparison of ab initio calculations and fits of the structural changes to experimental inertial parameters both in the basis of internal coordinates as well as in vibrational distortion coordinates. It is shown that the use of vibrational distortion coordinates leads to better agreement with the results of ab initio optimized structures compared to the use of internal coordinates in cases, that the inertial data are not sufficient for a complete structure determination. 1,2-dimethoxybenzene has been found to be only very slightly ortho-quinoidally distorted upon electronic excitation, in contrast to former expectations.
关键词： rotational constants,ab initio,pseudo-Kraitchman,evolutionary algorithms,Dimethoxybenzene,high resolution electronic spectroscopy
更新于2025-09-19 17:15:36