- 标题
- 摘要
- 关键词
- 实验方案
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Method to improve degraded range resolution due to non-ideal factors in FMCW radar
摘要： This paper reports a method to improve a degraded range resolution for FMCW radar. The proposed post-processing method can achieve an improved range resolution without increasing a signal bandwidth by eliminating factors that can degrade the range resolution based on the non-negative least-squares method. For an FMCW radar adopting the post-processing method with the center frequency of 76.5 GHz and the signal bandwidth of 200 MHz, simulation results show that the degraded range resolution of 160 cm is improved to 70 cm, and measurements show that two corner reflectors with the radar cross section of 10 dBsm located at 70 cm range intervals can be distinguished.
关键词： FMCW,non-negative least-squares method,radar,range resolution,signal bandwidth
更新于2025-09-23 15:22:29
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[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 - Monte Carlo Analysis of Orbital Station Motion Parameter Errors Influence on Sar Azimuth Resolution Degradation
摘要： Orbital stations can be an alternative platform choice for SAR payloads besides professional remote sensing satellite platform. However, such platform cannot provide as precision motion parameters as remote sensing satellite platform for SAR imaging due to its unique structure. The influence of motion parameter errors on SAR azimuth resolution degradation should be taken into consideration. Selecting the second order phase error caused by Doppler frequency rate with error as intermediate variable between motion parameter errors and SAR azimuth resolution, this paper proposed a Monte Carlo simulation model has been set up to obtain the specific probability distribution of SAR azimuth resolution degradation. A typical Monte Carlo simulation result is given to show the effectiveness of the method and may help actual SAR payload system design.
关键词： Orbital Station,Monte Carlo,SAR,Azimuth Resolution Degradation,Motion Parameter Errors
更新于2025-09-23 15:22:29
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[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 - Comparative Study of Feature Extraction Approaches for Ship Classification in Moderate-Resolution SAR Imagery
摘要： This paper presents a comparative study of existing feature extraction approaches for ship classification in moderate-resolution synthetic aperture radar (SAR) images. Ship classification is a key functionality in many maritime surveillance applications. For efficient ship classification, appropriate feature extraction is crucial. Most of existing studies have used high-resolution images. For maritime surveillance, however, wide-area coverage is essential whereas it inevitably reduces the spatial resolution. In this paper, we evaluate the applicability of representative methods to moderate-resolution images. The evaluated methods are hand-crafted feature extraction (HCF), principal component analysis (PCA) and autoencoder (AE) based on neural-network. The evaluation is done on the basis of accuracy for two-class ship classification into tanker and cargo. The experiments demonstrate that AE outperforms HCF and PCA in classification accuracy by 7.4% and 2.6%, respectively. Furthermore, AE performs best even in classification of challenging cases such as small ships.
关键词： feature extraction,ship classification,moderate resolution,deep learning,SAR,maritime
更新于2025-09-23 15:22:29
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[IEEE 2018 Digital Image Computing: Techniques and Applications (DICTA) - Canberra, Australia (2018.12.10-2018.12.13)] 2018 Digital Image Computing: Techniques and Applications (DICTA) - Inter-Subject Image Registration of Clinical Neck MRI Volumes using Discrete Periodic Spline Wavelet and Free form Deformation
摘要： This paper presents a framework for inter-patient image registration which uses a multi-thresholds, multi-similarity measures and multi-transformations based on compactly supported spline and discrete periodic spline wavelets (DPSWs) using the Gauss-Newton gradient descent (GNGD) and gradient descent (GD) optimization methods. Our primary intellectual contribution is incorporating DPSWs in the transformation while another includes fusing out-of-range concept in a surface matching technique which is implemented by a multi-transformations and multi-similarity measures. In particular, as a true deformation cannot be achieved by single combination of transformation, similarity measure (SM) and optimization of a registration process, a moving image is required to be brought within the range of a registration. On the other hand, the surface matching technique involves an edge position difference (EPD) SM in which coarse to fine surfaces are matched using multiple thresholds with a spline-based free from deformation (FFD) method. The registration experiments were performed on 3D clinical neck magnetic resonance (MR) images, with the results showing that our proposed method provides good accuracy and robustness.
关键词： Image registration,edge position difference,multi-resolution,inter-subject registration,optimization,discrete periodic spline wavelet
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE 3rd International Conference on Image, Vision and Computing (ICIVC) - Chongqing (2018.6.27-2018.6.29)] 2018 IEEE 3rd International Conference on Image, Vision and Computing (ICIVC) - Compressive Hyperspectral Imaging and Super-resolution
摘要： Coded aperture snapshot spectral imager (CASSI) has been a popular spectral imaging architecture for its ability of capturing hyperspectral temporal resolution. However, such snapshot imaging system entails a large sacrifice in the spatial resolution of the data cube, since only a small amount of light gets into the imager during one snapshot. Also, the spatial resolution of the CASSI system is limited by the pixel size (and amount) of the detector, while it is difficult to fabricate a dense detector with small pixel size, especially for infrared spectral bands. Super-resolution is an advanced post-processing technique to alleviate such problem by exploiting the prior information of the image. In this letter, we try to realize image super-resolution from the perspective of developing new form of measurements by taking advantage of a modified CASSI system equipped with a coded aperture with higher spatial resolution than the detector, merging the SR model into the hardware configuration. Then the original data cube can be reconstructed from lower resolution measurements, thus the super-resolution is realized during the compressive sensing reconstruction process. The new system can be achieved based on the classical CASSI architecture in two dual ways, one by replacing the coded aperture with a higher resolution one and the other by substituting the focal plane array (FPA) detector with a lower resolution one. The experiments show that, we can recover images of higher quality with the first modification of CASSI system above, simply using a higher resolution coded aperture.
关键词： super resolution,compressive sensing,spectral imaging
更新于2025-09-23 15:22:29
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Improving the Signal-to-noise Ratio of Super Resolution Imaging Based on Single Pixel Camera
摘要： Based on the theories of single pixel camera and compressed sensing image reconstruction, the sparse basis, the projection method of measurement matrix and the signal reconstruction algorithm are optimized. Firstly, for the sparse representation of image, the restraint matrix is designed combining the characteristics of wavelet sparse coefficients to enhance the sparse representation ability of the discrete wavelet base, which improves the quality of image reconstruction and imaging by single pixel camera. Then in the single pixel camera system, the projection method is improved according to the characteristics of the DMD micro-mirror, and a new bilateral projection method based on the block diagonal measurement matrix is proposed to realize the super resolution imaging of the outdoor scene, reducing the number of measurement and improving the imaging quality. Finally, for the algorithm of image reconstruction, combining the characteristics of convex optimization and non-convex optimization algorithms, a new algorithm from convex optimization approximately to non convex optimization algorithm is proposed, and compared with traditional image reconstruction algorithm such as greedy pursuit algorithm, minimum norm algorithm and image interpolation, the peak signal to noise ratio (PSNR) and imaging quality of reconstructed images are effectively improved. The feasibility of the proposed methods is demonstrated by simulation experiments and imaging experiments of single pixel camera.
关键词： measurement matrix,Single pixel camera,sparse representation,super resolution,image reconstruction
更新于2025-09-23 15:22:29
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Nonlocal Patch Tensor Sparse Representation for Hyperspectral Image Super-Resolution
摘要： This paper presents a hyperspectral image (HSI) super-resolution method which fuses a low-resolution hyperspectral image (LR-HSI) with a high-resolution multispectral image (HR-MSI) to get high-resolution HSI (HR-HSI). The proposed method first extracts the nonlocal similar patches to form a nonlocal patch tensor (NPT). A novel tensor-tensor product (t-product) based tensor sparse representation is proposed to model the extracted NPTs. Through the tensor sparse representation, both the spectral and spatial similarities between the nonlocal similar patches are well preserved. Then, the relationship between the HR-HSI and LR-HSI is built using t-product which allows us to design a unified objective function to incorporate the nonlocal similarity, tensor dictionary learning, and tensor sparse coding together. Finally, Alternating Direction Method of Multipliers (ADMM) is used to solve the optimization problem. Experimental results on three data sets and one real data set demonstrate that the proposed method substantially outperforms the existing state-of-the-art HSI super-resolution methods.
关键词： tensor dictionary learning,Hyperspectral image,nonlocal patch tensor,tensor sparse coding,super-resolution
更新于2025-09-23 15:22:29
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[Advances in Intelligent Systems and Computing] Soft Computing for Problem Solving Volume 817 (SocProS 2017, Volume 2) || Temperature Resolution and Spatial Resolution Improvement of BOCDR-Based DTS System Using Particle Swarm Optimization Algorithm
摘要： Temperature resolution and spatial resolution are major performance metrics in any distributed temperature sensing (DTS) system. In this paper, we have presented a detailed analysis on the performance of a Brillouin optical correlation domain reflectometry (BOCDR)-based DTS (BOCDR-DTS) system. Particle swarm optimization (PSO) evolutionary algorithm is being used in this paper to improve the performance of the proposed BOCDR-DTS system. Using this optimization algorithm, we minimized the Brillouin frequency shift (BFS) error in sensing system. As a consequence of this, the achieved temperature and spatial resolution are ~0.839 °C and ~43 cm, respectively. The results were simulated using MATLAB version 15.0.
关键词： Spontaneous Brillouin scattering,Distributed temperature sensing,Particle swarm optimization (PSO),Temperature resolution and spatial resolution,Brillouin frequency shift,Optical correlation domain reflectometry (OCDR)
更新于2025-09-23 15:21:21
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Use of YAP(Ce) in the development of high spatial resolution radiation imaging detectors
摘要： A scintillator with a high light output is considered to be required for the development of high spatial resolution radiation imaging detectors. In contrast to this scientific consensus, we found that high spatial resolution images can be obtained using a medium light output scintillator comprising cerium-doped yttrium aluminum perovskite, YA1O3 (YAP(Ce)). We evaluated the performance of a radiation imaging detector comprising a 0.5 mm thick YAP(Ce) plate, which was optically coupled to a 25.4 mm (1-inch) square position-sensitive photomultiplier. The Anger principle was used to calculate the radiation positions. The spatial resolution and energy resolution for the imaging detector with 5.5 MeV alpha particles were 0.2 mm full width at half-maximum (FWHM) and 7.4% FWHM, respectively. The spatial resolutions for 60 keV gamma photons and ~32 keV X-rays were ~ 0.6 mm FWHM and ~ 0.8 mm FWHM, respectively. The spatial resolution of the detector when imaging beta particles at a maximum energy of 254 keV was less than 0.6 mm FWHM. We conclude that YAP(Ce) is a promising scintillator for developing high spatial resolution and high energy resolution radiation detectors for imaging alpha particles, beta particles, and gamma photons.
关键词： YAP(Ce),energy resolution,position-sensitive photomultiplier,spatial resolution
更新于2025-09-23 15:21:21
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Super-resolution imaging using nano-bells
摘要： In this paper we demonstrate a new scheme for optical super-resolution, inspired, in-part, by PALM and STORM. In this scheme each object in the field of view is tagged with a signal that allows them to be detected separately. By doing this we can identify and locate each object separately with significantly higher resolution than the diffraction limit. We demonstrate this by imaging nanoparticles significantly smaller than the optical resolution limit. In this case the “tag” we have used is the frequency of vibration of nanoscale “bells” made of metallic nanoparticles whose acoustic vibrational frequency is in the multi-GHz range. Since the vibration of the particles can be easily excited and detected and the frequency is directly related to the particle size, we can separate the signals from many particles of sufficiently different sizes even though they are smaller than, and separated by less than, the optical resolution limit. Using this scheme we have been able to localise the nanoparticle position with a precision of ~3 nm. This has many potential advantages - such nanoparticles are easily inserted into cells and well tolerated, the particles do not bleach and can be produced easily with very dispersed sizes. We estimate that 50 or more different particles (or frequency channels) can be accessed in each optical point spread function using the vibrational frequencies of gold nanospheres. However, many more channels may be accessed using more complex structures (such as nanorods) and detection techniques (for instance using polarization or wavelength selective detection) opening up this technique as a generalized method of achieving super-optical resolution imaging.
关键词： optical resolution limit,acoustic vibrational frequency,nanoparticles,nano-bells,super-resolution imaging
更新于2025-09-23 15:21:21