scholarly journals Knowledge-Aided Doppler Beam Sharpening Super-Resolution Imaging by Exploiting the Spatial Continuity Information

Sensors ◽  
2019 ◽  
Vol 19 (8) ◽  
pp. 1920 ◽  
Author(s):  
Hongmeng Chen ◽  
Zeyu Wang ◽  
Jing Liu ◽  
Xiaoli Yi ◽  
Hanwei Sun ◽  
...  
Keyword(s):  
Dwell Time ◽  
Spatial Coherence ◽  
Super Resolution ◽  
Data Set ◽  
Spatial Continuity ◽  
Range Resolution ◽  
Imaging Model ◽  
Equivalent Number ◽  
The Cross ◽  
Imaging Performance

This paper deals with the problem of high cross-range resolution Doppler beam sharpening (DBS) imaging for airborne wide-area surveillance (WAS) radar under short dwell time situations. A knowledge-aided DBS (KA-DBS) imaging algorithm is proposed. In the proposed KA-DBS framework, the DBS imaging model for WAS radar is constructed and the cross-range resolution is analyzed. Since the radar illuminates the imaging scene continuously through the scanning movement of the antenna, there is strong spatial coherence between adjacent pulses. Based on this fact, forward and backward pulse information can be predicted, and the equivalent number of pulses in each coherent processing interval (CPI) will be doubled based on the autoregressive (AR) technique by taking advantage of the spatial continuity property of echoes. Finally, the predicted forward and backward pulses are utilized to merge with the initial pulses, then the newly merged pulses in each CPI are utilized to perform the DBS imaging. Since the number of newly merged pulses in KA-DBS is twice larger than that in the conventional DBS algorithm with the same dwell time, the cross-range resolution in the proposed KA-DBS algorithm can be improved by a factor of two. The imaging performance assessment conducted by resorting to real airborne data set, has verified the effectiveness of the proposed algorithm.

scholarly journals Strip-Mode Microwave Staring Correlated Imaging with Self-Calibration of Gain–Phase Errors

Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1079 ◽  
Author(s):  
Rui Xia ◽  
Yuanyue Guo ◽  
Weidong Chen ◽  
Dongjin Wang
Keyword(s):  
Error Estimation ◽  
Phase Error ◽  
Super Resolution ◽  
Image Splicing ◽  
Initial Value ◽  
Self Calibration ◽  
Phase Errors ◽  
Imaging Model ◽  
Multiple Imaging ◽  
Imaging Performance

Microwave staring correlated imaging (MSCI) can realize super resolution imaging without the limit of relative motion with the target. However, gain–phase errors generally exist in the multi-transmitter array, which results in imaging model mismatch and degrades the imaging performance considerably. In order to solve the problem of MSCI with gain–phase error in a large scene, a method of MSCI with strip-mode self-calibration of gain–phase errors is proposed. The method divides the whole imaging scene into multiple imaging strips, then the strip target scattering coefficient and the gain–phase errors are combined into a multi-parameter optimization problem that can be solved by alternate iteration, and the error estimation results of the previous strip can be carried into the next strip as the initial value. All strips are processed in multiple rounds, and the gain–phase error estimation results of the last strip can be taken as the initial value and substituted into the first strip for the correlated processing of the next round. Finally, the whole imaging in a large scene can be achieved by multi-strip image splicing. Numerical simulations validate its potential advantages to shorten the imaging time dramatically and improve the imaging and gain–phase error estimation performance.

scholarly journals Three-Dimensional Imaging Method for Array ISAR Based on Sparse Bayesian Inference

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3563
Author(s):  
Zekun Jiao ◽  
Chibiao Ding ◽  
Longyong Chen ◽  
Fubo Zhang
Keyword(s):  
Bayesian Inference ◽  
3D Imaging ◽  
Three Dimensional ◽  
Super Resolution ◽  
Information Criterion ◽  
Radar Data ◽  
Imaging Method ◽  
Model Order Selection ◽  
Imaging Model ◽  
Imaging Performance

The problem of synthesis scatterers in inverse synthetic aperture radar (ISAR) make it difficult to realize high-resolution three-dimensional (3D) imaging. Radar array provides an available solution to this problem, but the resolution is restricted by limited aperture size and number of antennas, leading to deterioration of the 3D imaging performance. To solve these problems, we propose a novel 3D imaging method with an array ISAR system based on sparse Bayesian inference. First, the 3D imaging model using a sparse linear array is introduced. Then the elastic net estimation and Bayesian information criterion are introduced to fulfill model order selection automatically. Finally, the sparse Bayesian inference is adopted to realize super-resolution imaging and to get the 3D image of target of interest. The proposed method is used to process real radar data of a Ku band array ISAR system. The results show that the proposed method can effectively solve the problem of synthesis scatterers and realize super-resolution 3D imaging, which verify the practicality of our proposed method.

scholarly journals MNBDR: A Module Network Based Method for Drug Repositioning

Genes ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 25
Author(s):  
He-Gang Chen ◽  
Xiong-Hui Zhou
Keyword(s):  
Gene Expression ◽  
Protein Interactions ◽  
Drug Response ◽  
Drug Repositioning ◽  
Expression Profiles ◽  
Drug Repurposing ◽  
Recent Decade ◽  
Data Set ◽  
Module Network ◽  
The Cross

Drug repurposing/repositioning, which aims to find novel indications for existing drugs, contributes to reducing the time and cost for drug development. For the recent decade, gene expression profiles of drug stimulating samples have been successfully used in drug repurposing. However, most of the existing methods neglect the gene modules and the interactions among the modules, although the cross-talks among pathways are common in drug response. It is essential to develop a method that utilizes the cross-talks information to predict the reliable candidate associations. In this study, we developed MNBDR (Module Network Based Drug Repositioning), a novel method that based on module network to screen drugs. It integrated protein–protein interactions and gene expression profile of human, to predict drug candidates for diseases. Specifically, the MNBDR mined dense modules through protein–protein interaction (PPI) network and constructed a module network to reveal cross-talks among modules. Then, together with the module network, based on existing gene expression data set of drug stimulation samples and disease samples, we used random walk algorithms to capture essential modules in disease development and proposed a new indicator to screen potential drugs for a given disease. Results showed MNBDR could provide better performance than popular methods. Moreover, functional analysis of the essential modules in the network indicated our method could reveal biological mechanism in drug response.

scholarly journals Simultaneous spatiotemporal super-resolution and multi-parametric fluorescence microscopy

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jagadish Sankaran ◽  
Harikrushnan Balasubramanian ◽  
Wai Hoh Tang ◽  
Xue Wen Ng ◽  
Adrian Röllin ◽  
...  
Keyword(s):  
Single Molecule ◽  
Temporal Dynamics ◽  
Growth Factor Receptor ◽  
Super Resolution ◽  
Actin Binding ◽  
Biological Knowledge ◽  
Data Set ◽  
Epidermal Growth ◽  
Molecular Brightness ◽  
Super Resolution Microscopy

AbstractSuper-resolution microscopy and single molecule fluorescence spectroscopy require mutually exclusive experimental strategies optimizing either temporal or spatial resolution. To achieve both, we implement a GPU-supported, camera-based measurement strategy that highly resolves spatial structures (~100 nm), temporal dynamics (~2 ms), and molecular brightness from the exact same data set. Simultaneous super-resolution of spatial and temporal details leads to an improved precision in estimating the diffusion coefficient of the actin binding polypeptide Lifeact and corrects structural artefacts. Multi-parametric analysis of epidermal growth factor receptor (EGFR) and Lifeact suggests that the domain partitioning of EGFR is primarily determined by EGFR-membrane interactions, possibly sub-resolution clustering and inter-EGFR interactions but is largely independent of EGFR-actin interactions. These results demonstrate that pixel-wise cross-correlation of parameters obtained from different techniques on the same data set enables robust physicochemical parameter estimation and provides biological knowledge that cannot be obtained from sequential measurements.

The climatic, topographic and litho-tectonic characteristics of badlands in Turkey

2021 ◽  
Author(s):  
Aydogan Avcioglu ◽  
Tolga Gorum ◽  
Abdullah Akbas ◽  
Mariano Moreno de las Heras ◽  
Omer Yetemen
Keyword(s):  
Critical Role ◽  
Sedimentary Rocks ◽  
Spatial Coherence ◽  
Google Earth ◽  
Controlling Factors ◽  
Mean Annual Precipitation ◽  
Rainfall Erosivity ◽  
Data Set ◽  
Anatolian Plateau ◽  
Precipitation Seasonality

<p>Badland areas are present in all continents, excluding Antarctica, and play a critical role in establishing local erosion and sedimentation rates. The presence of unconsolidated rocks (e.g., marls, sandstone, mudstone etc.) is a major driver controlling the distribution of badlands, which together with other environmental components, such as climate, tectonics, vegetation, and topography, determine their forms and processes. The mutual interaction of controlling factors in badlands areas provides a basis for developing a holistic approach to clarify their distribution patterns. Turkey's geodynamic evolution has led to the emergence of marine sedimentary rocks, pyroclastics, and continental clastics, especially in line with the uplift of the Anatolian Plateau and volcanism during the last 8 Ma.</p><p>This study aims to explore the country-scale distribution of badlands and the controlling factors of this badland distribution in Turkey. Remarkably wide badlands landscapes (4494 km<sup>2</sup>) have been visually inspected using Google Earth Pro<sup>TM</sup> to further digitize and extract geomorphological units by applying high-resolution multispectral images provided by WorldView-4/Maxar Technology and CNES/Airbus. To obtain exact boundaries, we eliminated contiguous flat areas surrounding the identified badlands by using red relief image map (RRIM) mosaics that express surface concavity and convexity combined with topographic slope derived from a digital elevation model of 5-m spatial resolution. Last, to determine the controlling factors of badlands distribution, we have compiled a global data set comprising 1-km resolution layers of mean annual precipitation, temperature and precipitation seasonality, aridity, NDVI, rainfall erosivity factor, elevation, and majority values of regional lithology in sub-catchments units. The enhanced investigation of the complex relationship that expresses the controlling factors of badlands distribution, has been conducted by K-means unsupervised cluster analysis.</p><p>Our comprehensive regional analyses exploring the distribution and environmental attributes of major Turkish badlands identified five different groups or clusters of badlands that display spatial coherence with climatic and tectonic settings. We argue that Turkey's climatic and topographic transition zones, varying from Mediterranean climate dominated areas to the more arid Central Anatolian Plateau, and tectonically‑induced topographic barriers play a relevant role in discriminating these groups of badlands. Moreover, the Anatolian diversity of sedimentary rocks, which consists of Neogene and Paleogene continental clastics, volcano clastics & pyroclastics, and lacustrine deposits, makes an essential contribution to the identified, extensive badland distribution.</p><p>This study has been produced benefiting from the 2232 International Fellowship for Outstanding Researchers Program of the Scientific and Technological Research Council of Turkey (TUBITAK) through grant 118C329. The financial support received from TUBITAK does not mean that the content of the publication is approved in a scientific sense by TUBITAK.</p>

Improvement of Horizontal Resolution by Doppler Image under Forced Vibration

2013 ◽  
Vol 596 ◽  
pp. 152-157 ◽  
Author(s):  
Takashi Miwa
Keyword(s):  
Numerical Simulation ◽  
Measurement System ◽  
Forced Vibration ◽  
Super Resolution ◽  
Region Of Interest ◽  
Horizontal Resolution ◽  
Range Resolution ◽  
Point Spread ◽  
Doppler Image ◽  
Spread Function

Generally, cross range resolution of a B-mode ultrasonic image is restricted by a point spread function of the measurement system. Although various super-resolution techniques are proposed, it is difficult to significantly improve the resolution with low calculation burden. In this paper, we propose a novel super-resolution technique in which the Doppler B-mode image is measured under forced vibration in the region of interest. The numerical simulation is carried out to demonstrate the validity of the proposed algorithm. It is shown that the cross range resolution is 3 times narrower than the original one.

scholarly journals On range super - resolution in a radar with many carriers. Simulation and experiment

2019 ◽  
pp. 24-29
Author(s):  
I. L. Nagornykh ◽  
N. D. Bazhenov
Keyword(s):  
Fourier Transform ◽  
Traditional Method ◽  
Super Resolution ◽  
Music Algorithm ◽  
Signal To Noise ◽  
Range Resolution ◽  
Probing Signal ◽  
Simulation And Experiment ◽  
The Fourier Transform ◽  
Research Show

The paper focuses on radar operation and the results of its simulation. The probing signal of the radar is a set of 16 orthogonal carriers. To determine the range in such radar, the MUSIC algorithm was applied, which relates to super - resolution methods. Findings of research show that the MUSIC algorithm makes it possible to increase the radar range resolution in the signal - to-noise 0-20 dB ratio by 4-8 times as compared with the traditional method based on the Fourier transform. The developed models were experimentally verified

A novel dual-radar fusion method for improving the cross-range resolution of ISAR imagery

2021 ◽  
Vol 13 (3) ◽  
pp. 236-246
Author(s):  
Yicheng Jiang ◽  
Ruida Chen ◽  
Yun Zhang
Keyword(s):  
Fusion Method ◽  
Range Resolution ◽  
The Cross

A Near‐Real‐Time Version of the Cross‐Calibrated Multiplatform (CCMP) Ocean Surface Wind Velocity Data Set

2019 ◽  
Vol 124 (10) ◽  
pp. 6997-7010
Author(s):  
Carl A. Mears ◽  
Joel Scott ◽  
Frank J. Wentz ◽  
Lucrezia Ricciardulli ◽  
S. Mark Leidner ◽  
...  
Keyword(s):  
Real Time ◽  
Wind Velocity ◽  
Surface Wind ◽  
Ocean Surface ◽  
Velocity Data ◽  
Data Set ◽  
Ocean Surface Wind ◽  
The Cross

scholarly journals Controlling the non-linear emission of upconversion nanoparticles to enhance super-resolution imaging performance

Nanoscale ◽  
2020 ◽  
Vol 12 (39) ◽  
pp. 20347-20355
Author(s):  
Simone De Camillis ◽  
Peng Ren ◽  
Yueying Cao ◽  
Martin Plöschner ◽  
Denitza Denkova ◽  
...  
Keyword(s):  
Super Resolution ◽  
Upconversion Nanoparticles ◽  
Non Linear ◽  
Resolution Imaging ◽  
Imaging Performance ◽  
Luminescence Characteristics

Convenient design of fully Yb-based upconversion nanoparticles enables control of their luminescence characteristics and enhances super-resolution imaging performance.

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