- Advanced SAR Imaging Techniques
- Sparse and Compressive Sensing Techniques
- Microwave Imaging and Scattering Analysis
- Ultrasonics and Acoustic Wave Propagation
- Synthetic Aperture Radar (SAR) Applications and Techniques
- Optical measurement and interference techniques
- Image Processing Techniques and Applications
- Advanced Image Processing Techniques
- Image and Signal Denoising Methods
- Photoacoustic and Ultrasonic Imaging
- Advanced Optical Sensing Technologies
- Optical Systems and Laser Technology
- Radar Systems and Signal Processing
- Blind Source Separation Techniques
- Spectroscopy Techniques in Biomedical and Chemical Research
- Advanced Neural Network Applications
- Infrared Target Detection Methodologies
- Geophysical Methods and Applications
- Advanced MIMO Systems Optimization
- Ginseng Biological Effects and Applications
- COVID-19 diagnosis using AI
- Space Satellite Systems and Control
- Millimeter-Wave Propagation and Modeling
- Image and Video Quality Assessment
- Agriculture, Soil, Plant Science
National University of Defense Technology
2015-2024
Nanyang Technological University
2017-2020
Learning based approaches have witnessed great successes in blind single image super-resolution (SISR) tasks, however, handcrafted kernel priors and learning are typically required. In this paper, we propose a Meta-learning Markov Chain Monte Carlo SISR approach to learn from organized randomness. concrete, lightweight network is adopted as generator, optimized via the MCMC simulation on random Gaussian distributions. This procedure provides an approximation for rational blur kernel,...
Autofocusing technology is an essential step of Inverse Synthetic Aperture Radar (ISAR) imaging, whose performance has great influence on the quality radar image. As far as existed autofocusing methods are concerned, based minimum entropy criterion robust and have been widely applied in both (SAR) ISAR imaging. However, Minimum Entropy (MEA) usually suffer from heavy computation burden because complex formula image optimal search phase error. In this paper, a novel fast MEA method Newton...
Sparse aperture ISAR autofocusing and imaging is generally achieved by methods of compressive sensing (CS), or, sparse signal recovery, because non-uniform sampling disables fast Fourier transform (FFT)-the core traditional algorithms. Note that the CS based are often computationally heavy to execute, which limits their applications in real-time systems. The improvement computational efficiency either necessary or at least highly desirable promote practical usage. This paper proposes an...
Sparse aperture radar imaging is generally achieved by methods of compressive sensing (CS), or, sparse signal recovery (SSR). However, most the traditional SSR cannot produce focused image stably, which limits their applications. l <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> regularization and alternating direction method multipliers(ADMM) are applied to problem, but its performance sensitive selection model parameters. This paper...
Sparsity and Shannon entropy have been widely used in inverse synthetic aperture radar (ISAR) imaging. The minimum criterion is usually applied the translational motion compensation sparse constraint azimuth In this paper, we combine these two criteria to develop a novel autofocusing algorithm for ISAR (SA-ISAR) First, Laplace approximation-based variational Bayesian inference with Laplacian scale mixture prior proposed SA-ISAR Then, accomplished by minimizing image of reconstructed within...
A novel radar high-resolution range profile (HRRP) target recognition method based on a stacked autoencoder (SAE) and extreme learning machine (ELM) is presented in this paper. As key component of deep structure, the SAE does not only learn features by making use data, it also obtains feature expressions at different levels data. However, with hard to achieve good generalization performance fast speed. ELM, as new algorithm for single hidden layer feedforward neural networks (SLFNs), has...
For sparse aperture (SA) radar echoes, the coherence between undersampled pulses is destroyed, which challenges effectiveness of traditional autofocusing and scaling in inverse synthetic (ISAR) imaging. A novel Bayesian ISAR algorithm for proposed, utilizes Laplacian scale mixture, as prior image, variational inference based on approximation to derive its posterior. In addition, it learns phase error, rotational velocity, center target from echo automatically during reconstruction so achieve...
Inverse synthetic aperture radar (ISAR) imaging for the target with micro-motion parts is influenced by micro-Doppler (m-D) effects. In this case, echo generally decomposed into components from main body and of target, respectively, to remove m-D effects derive a focused ISAR image body. For sparse data, however, intentionally or occasionally under-sampled, which defocuses introducing considerable interference, deteriorates performance signal decomposition removal To address issue, paper...
In the case of sparse aperture, coherence between pulses radar echo is destroyed, which challenges inverse synthetic aperture (ISAR) autofocusing and imaging. Mathematically, reconstructing ISAR image from a linear underdetermined problem, which, by nature, can be solved fast developed compressive sensing (CS) or signal recovery theory. However, CS-based imaging algorithms are generally computationally heavy, becomes bottleneck preventing their applications to real-time system. this article,...
Inverse synthetic aperture radar (ISAR) imaging for the sparse data is affected by considerable artifacts, because under-sampling of produces high-level grating and side lobes. Noting ISAR image generally exhibits strong sparsity, it often obtained signal recovery (SSR) in case aperture. The SSR, however, dominated isolated scatterers, resulting difficulty to recognize structure target. This paper proposes a novel approach enhance from data. Although scatterers target are image, they should...
This study proposes a model-driven deep network based on the linear alternating direction method of multipliers (L-ADMM), to solve problem whereby inverse synthetic aperture radar (ISAR) generates defocused images targets exhibiting micro-motion with sparse aperture. The unfolds operation process L-ADMM into network, and automatically optimizes parameters through learning instead manually adjusting parameters, which can better obtain images. Analyses data acquired simulations experimental...
This paper proposes novel bistatic inverse synthetic aperture radar (ISAR) imaging algorithm for the target with complex motion under low signal to noise ratio (SNR) condition. Note ISAR system generally suffers from a lower SNR than monostatic one because of its non-mirror reflection geometry. A de-noising method, therefore, is proposed improve range profiles, which accumulates aligned profiles non-coherently obtain window suppression. In addition, since induces non-stationary Doppler,...
This paper proposes a learning aided gradient descent (LAGD) algorithm to solve the weighted sum rate (WSR) maximization problem for multiple-input single-output (MISO) beamforming. The proposed LAGD directly optimizes transmit precoder through implicit based iterations, at each of which optimization strategy is determined by neural network, and thus, dynamic adaptive. At instance problem, this network initialized randomly, updated throughout iterative solution process. Therefore, can be...
Compared to 2D inverse synthetic aperture radar (ISAR) images of a space target, its 3D model can provide adequate details and accurate measurement parameters. However, it is challenging tackle the problem feature extraction correlation during reconstruction targets purely based on image sequences, due their lack clear evidence in imaging similarity compared optical images. To address this problem, paper proposes neural radiance fields (i.e. RaNeRF), which novel method using only observed...
This paper proposes a fast and novel cross-range scaling algorithm for inverse synthetic aperture radar (ISAR) imaging. The rotational motion of the target unavoidably results in high-order phase errors that blur ISAR image. To achieve compensate quadratic error, velocity center are jointly estimated by optimizing image quality terms either entropy or contrast. Since it is two-dimensional nonlinear optimization problem, grid search generally computationally inefficient inaccurate. improve...
This paper presents a new sparse signal recovery algorithm using variational Bayesian inference based on the Laplace approximation. The is modeled as Laplacian scale mixture (LSM) prior. with models challenge because prior not conjugate to Gaussian likelihood. To solve this problem, we first introduce inverse-gamma prior, which model distinctive scaling parameters of priors. Then posterior signal, approximated by approximation, found be distributed expectation being result maximum (MAP)...
The cross-range resolution of inverse synthetic aperture radar (ISAR) images is influenced by undersampled data under the sparse (SA) condition. Recently, learning-based methods have been applied to SA-ISAR imaging and achieved impressive performance. Learning-based can achieve satisfactory results training on large datasets. However, these may fail reconstruct high-quality in practical applications due limitations. In this article, we consider problem within a meta-learning framework....
For inverse synthetic aperture radar (ISAR) imaging under sparse (SA) conditions, the rotation motion compensation is seldom considered. However, with improvement of resolution, migration through resolution cell (MTRC) cannot be ignored. Traditional methods for generally fail in SA cases. This article proposes a method to jointly implement and MTRC structured Bayesian learning (SBL) framework. Due coupling fast time slow time, observation model established vectorized form. To reduce...
For sparse aperture (SA) radar imaging, the phase errors are difficult to be estimated, which challenges traditional autofocusing for inverse synthetic (ISAR) imaging. A novel Bayesian ISAR algorithm SA is proposed. We unfold Laplace prior two layers so that full variational inference can derived. To further exploit knowledge on structure of images, dependencies among adjacent pixels considered design a structured prior. In addition, minimum entropy criterion utilized estimate error during...
The micro-Doppler (m-D) effect caused by micro-motion degrades the readability of inverse synthetic aperture radar (ISAR) image. To achieve well-focused ISAR image target with part, this paper proposes a novel approach for removal m-D Note that range profiles rigid body are similar to each other, making respective data matrix low-rank. Those in contrary, generally fluctuate different cells, whose is sparse. Therefore, can be naturally solved robust principal component analysis (RPCA)-a...
Sparse aperture inverse synthesis radar (SA-ISAR) imaging is generally solved by compressed sensing (CS) methods or sparse signal recovery (SSR). Many SSR focus on the sparsity of images only, which achieves unsatisfactory results structural data. In addition, most traditional CS algorithms suffer from a heavy computational burden. this article, new deep unfolding network called pattern-coupled Bayesian learning (PCSBL)-generalized approximate message passing (GAMP)-Net proposed. The...
The inverse synthetic aperture radar (ISAR) images are often afflicted by boundary blurring, discontinuity, sidelobe effects of strong scattering points, a large dynamic range gray values, and azimuth defocus, which pose significant challenges to image segmentation. This paper proposes novel semantic segmentation method for ISAR space targets. is based on contrastive learning (CL) Non-Local Unet (NL-Unet). First, the roughly segments target contour using binary tags remove interference...
Obtained by wide band radar system, high resolution range profile (HRRP) is the projection of scatterers target to line-of-sight (LOS). HRRP reconstruction unavoidable for inverse synthetic aperture (ISAR) imaging, and particular usage recognition, especially in cases that ISAR image not able be achieved. For high-speed moving target, however, its stretched order phase error. To obtain well-focused HRRP, error induced velocity should compensated, utilizing either measured or estimated...