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IET International Radar Conference 2023, IRC 2023

作者： Chen, Min Shang, Mingyang Qiu, Xiaolan Wen, Xuejiao Suzhou Key Laboratory of Microwave Imaging Processing and Application Technology Suzhou215123 China Key Laboratory of Technology in Geo-spatial Information Processing and Application Systems Chinese Academy of Sciences Beijing100190 China Suzhou Aerospace Information Research Institute Suzhou215123 China Aerospace Information Research Institute Chinese Academy of Sciences Beijing100094 China School of Electronic Electrical and Communication Engineering University of Chinese Academy of Sciences Beijing100049 China

ISBN: (纸本)9781839539954

Sliding spotlight mode is a widely used working mode for spaceborne synthetic aperture radar (SAR) systems. It can realize a higher azimuth resolution than the stripmap mode and a wider observation swath than the spotlight mode. For sliding spotlight SAR, due to the higher azimuth resolution, the accuracy of the Doppler parameters is of great importance since it affects the construction of the azimuth matching filters and further impacts the focusing quality of the final image. While most of the existing Doppler estimation methods are not applicable for sliding spotlight mode since they do not consider the azimuth spectrum aliasing problem. In this paper, we conduct a detailed analysis of the variation of azimuth time-frequency relationship during the azimuth preprocessing of the two-step focusing process for spaceborne sliding spotlight SAR. Based on the analysis, we propose a new Doppler parameter estimation method dedicated to azimuth preprocessing. We also present our experimental results of real data which can verify the effectiveness of our proposed method. © The Institution of Engineering & technology 2023.

关键词： Doppler radar

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A New Approach to Airborne High Resolution SAR Motion Compensation for Large Trajectory Deviations*

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Chinese Journal of Electronics 2023年第4期21卷 764-769页

作者： Dadi MENG Donghui HU Chibiao DING Key Laboratory of Technology in Geospatial Information Processing and Application System Chinese Academy of Sciences Beijing China Institute of Electronics Chinese Academy of Sciences Beijing China

The Two-step algorithm (TSA) is widely used for trajectory deviation compensation of airborne Synthetic aperture radar (SAR), by which most of the motion errors are compensated before Range curve migration compensation (RCMC) and the residual after the RCMC. We found that the RCMC in the presence of the residual motion errors results in additional range shift errors hard to be compensated for. Based on theoretical investigations, this shortage of TSA is reported and a new compensation scheme which greatly alleviates the RCMC induced errors is proposed. Besides, range resampling considering the residual motion errors is very convinent, which, however, is boresome in TSA. The new method is effective to compensate the high resolution SAR systems for large trajectory deviations, which is hard to be achieved by TSA because of the uncompensated errors. Results on the simulated data are provided to demonstrate the effectiveness of the new method.

关键词： Image resolution Azimuth Motion compensation Trajectory Synthetic aperture radar

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Domain Knowledge Based Small Sample Ship Target Detection Method 3

Domain Knowledge Based Small Sample Ship Target Detection Me...

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3rd China International SAR Symposium, CISS 2022

作者： Zhou, Jianing Li, Zheng Yang, Wei Zou, Fei Wang, Hui BeiHang University School of Electronic and Information Engineering Beijing China Aerospace Information Research Institute Beijing China Chinese Academy of Sciences Key Laboratory of Technology in Geospatial Information Processing and Application System Beijing China Beijing Institute of Remote Sensing Information Beijing China Shanghai Institute of Satellite Engineering Shanghai China

ISBN: (数字)9798350398717

ISBN: (纸本)9798350398717

Synthetic Aperture Radar (SAR) is widely used in ship target detection because of its ability to operate under various weather conditions. However, some target images are difficult to obtain and label, resulting in a small sample size, which limits the development of target detection. Aiming at the problem of ship target detection in small sample SAR images, domain knowledge is used to revise and enhance the basic model in this paper. Firstly, a lightweight convolutional neural network model more suitable for small-sample SAR image ship target classification is proposed, involving target pixel and aspect ratio as domain knowledge to correct the classification results. Then, for ship target detection in SAR images, the acquisition method of scale class domain knowledge is improved. Moreover, texture-related domain knowledge based on the gray level co-occurrence matrix is extracted and used as classification features for the model to revise the model. Finally, Marine Targets Classification Dataset (MTCD) and Marine Targets Detection Dataset (MTDD) are briefly introduced and adjusted to meet the requirements of this research through screening and modification. The test results on balanced MTDD and small-sample datasets demonstrate the effectiveness of domain knowledge in improving network performance. © 2022 IEEE.

关键词： Deep learning

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TOPOGRAPHIC CORRECTION OF ETM IMAGES BASED ON SMOOTHED TERRAIN

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Journal of Electronics(China) 2012年第3期29卷 271-278页

作者： Jiang Kang Zhao Yongchao Geng Xiurui Tang Hairong Key Laboratory of Technology in Geo-spatial Information Processing and Application Systems Beijing 100100China Institute of Electronics Chinese Academy of SciencesBeijing 1001P0China Graduate University Chinese Academy of SciencesBeijing 100040China

A new empirical topographic correction method is proposed in this paper. The main idea of the new method is smoothing the slope angle of terrain in the first place and then performing the cosine correction based on the smoothed terrain. A comparison is conducted among the new method and several other common methods using Landsat-7 ETM+ data. Visual analysis and statistical analysis are adopted to assess the performance of these methods from two aspects: overcorrection, homogeneity within a land cover class. Comparison results indicate that the new method is superior to the cosine correction, Gamma correction, Sun-Canopy-Sensor correction, and Minnaert correction. Compared with common methods, the proposed one can eliminate overcorrection better and is an effective topographic correction method.

关键词： Topographic correction Landsat-7 ETM Smoothed terrain

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Threshold determination for dynamic programming based track-before-detect in passive bistatic radar

Threshold determination for dynamic programming based track-...

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International Conference on Signal processing Proceedings (ICSP)

作者： Xin Guan Li-hua Zhong Dong-hui Hu Chi-biao Ding Key Laboratory of Technology in Geospatial Information Processing and Application System Institute of Electronics Chinese Academy of Sciences Beijing CN

Track-before-detect (TBD) is effective on weak target detection in passive bistatic radar (PBR). The probability of false alarm (PFA) and the probability of detection (PD) in TBD based on dynamic programming algorithm (DPA) are determined by threshold. The extreme value theory and generalized Pareto distribution are usually used to obtain the relationship between PD, PFA and threshold. However, DPA must be performed several times to estimate parameters resulting in much processing time. An iterative method based on Gaussian distribution is another solution but is not suitable for the Chi-square distribution in PBR. Therefore fast threshold determination methods without Gaussian assumption are proposed in this paper. First, a data simulation method is presented. Then an approximation of PD is introduced to further reduce the complexity. Moreover, empirical formulas based on the hypothesis of Chi-square distribution are developed for real-time processing. Simulations verify that the methods are more suitable for real-time processing.

关键词： Approximation methods Data models Monte Carlo methods Noise Complexity theory Target tracking Real-time systems

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Research on Integrated Deployment Method of Digital Earth Thematic application Model 1

Research on Integrated Deployment Method of Digital Earth Th...

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1st China Digital Earth Conference, CDEC 2019

作者： Danpu, Zhao Xianqing, Tai Zhijie, Ma Key Laboratory of Technology in Geospatial Information Processing and Application System Institute of Elec-tronics Chinese Academy of Sciences Beijing100190 China Research Center of Intelligent City and Intelligent Transportation CAS R and D Center for Internet of Things Wuxi214135 China

Nowadays, the digital earth not only relates to the technologies of surveying and mapping geography, but also includes the analysis and cross-application of various scientific data related to geographic information. It requires a computing environment and management for the corresponding thematic application models which supports the online analysis on the digital earth. So we proposed an integrated deployment method for digital earth thematic application models based on container cloud, which provides a flexible and scalable information integration and analysis architecture for digital earth. Firstly, a Docker image building module is designed to facilitate the user to quickly build the application model into a image. Then the Docker technology is used to implement the containerization of the application model to provide a stable running environment for the application model. Finally, the Kubernetes is used to dynamically manage the cluster resources to realize rapid expansion of computing resources. In addition, the HDFS is deployed, and the image files and various scientific data respectively store with Hbase and Apache file systems. It can ensure the read and write speed of the application model and the related data and log files. It also used zabbix framework to manage the monitoring index of the container cloud cluster to ensure the execution effect of the application model. Through the tests of typical application model, it is verified that the method can integrated deploy and apply the cross-domain, hetero-architecture, multi-version and multi-class application models on the digital earth. © Published under licence by IOP Publishing Ltd.

关键词： Containers

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The effects of channel imbalances on the azimuth multi-channel SAR 5

The effects of channel imbalances on the azimuth multi-chann...

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IET International Radar Conference 2020, IET IRC 2020

作者： Shang, Mingyang Qiu, Xiaolan Han, Bing Yang, Junying Ding, Chibiao Zhong, Lihua Zhou, Xiao Aerospace Information Research Institute Chinese Academic of Sciences Beijing China Key Laboratory of Technology in Geo-Spatial Information Processing and Application Systems Chinese Academy of Sciences Beijing China School of Electronic Electrical and Communication Engineering University of Chinese Academy of Sciences Beijing China National Key Laboratory of Microwave Imaging Technology Beijing100190 China

ISBN: (纸本)9781839535635

Azimuth multi-channel (AMC) synthetic aperture radar (SAR) is an effective technology to conquer the minimum antenna area constraint and can provide high-resolution and wide-swath (HRWS) SAR images compared with the conventional strip-map SAR. In order to suppress azimuth ambiguity, AMC SAR will face an important problem: channel imbalances estimation and compensation. At first, this paper theoretically analysis the effects of channel imbalances including amplitude imbalance, phase imbalance and range sampling time imbalance (RSTI) on AMC SAR images, where all these channel imbalances will introduce false targets in azimuth, and RSTI will also make a significant influence on the range of SAR images. And then, in order to validate the above result, some simulations based on the parameters are carried out, and the real image acquired by GF-3 is also described. In addition, the intensity, number, and position of false targets are discussed. Finally, this paper makes some conclusions and points out the problems of these results. © 2020 Institution of Engineering and technology. All rights reserved.

关键词： Synthetic aperture radar

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MACHINE LEARNING-BASED MULTI-CHANNEL EVALUATION POOLING STRATEGY FOR IMAGE QUALITY ASSESSMENT

MACHINE LEARNING-BASED MULTI-CHANNEL EVALUATION POOLING STRA...

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IEEE International Conference on Image processing

作者： Anzhou Hu Rong Zhang Dong Yin Wenlong Hu Department of Electronic Engineering and Information Science University of Science and Technology of China Key Laboratory of Geospatial Information Processing and Application System Technology Chinese Academy of Sciences

ISBN: (纸本)9781479923427

Multi-channel peculiarity is one of the most widely accepted human visual system (HVS) models for perceptual image quality assessment (IQA). Otherwise than extensive studies of channel decomposition and intra-channel distortion measure, relatively scant research effort has been devoted to develop efficient multichannel evaluation pooling strategies. In this paper, we review and address the limitations of the conventional pooling models based on HVS sensitivities-weighted average. Instead, we explore the utilization of machine learning for this pooling problem, since machine learning can establish an optimal and generalized mapping that models the highly complex relationship between the multi-channel distortion evaluations and the perceived image quality. Experiments based on available subjective IQA databases demonstrate the rationality, reliability and robustness of our proposed scheme.

关键词： Image quality assessment (IQA) Multi-channel model Evaluation pooling Machine learning

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An Error-Based Block Adjustment Method for Multi-Angle Satellite Imagery Without Ground Control Points

An Error-Based Block Adjustment Method for Multi-Angle Satel...

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IEEE International Geoscience and Remote Sensing Symposium

作者： Niangang Jiao Feng wang Hongjian You Kun Hu Mudan Yang Key Laboratory of Technology in Geo-Spatial Information Processing and Application Systems Institute of Electronics Beijing China

Geo-positioning accuracy improvement is one of the most important step of remote sensing image preprocessing. Traditional methods require a large number of ground control points (GCPs) which consuming lots of manpower and financial resources. With the resolution up to 0.8m, the original geo-positioning accuracy of the Chinese Gaofen (GF-2) multi-angle imagery is about 90m which means a limited application in geometric processing. In this paper, we propose a new method to improve the geometric performance of the multi-angle satellite imagery based on the geometric error sources of this experimental dataset without GCPs. Under the condition of weak intersection of our test dataset, we use a DEM-assisted approach to acquire a more accurate initial position accuracy of all tie points, and all extracted data is clustered by the Density based spatial clustering of applications with noise (DBSCAN) algorithm in order to eliminate points or impages with large positioning error automatically. Then, the error-based block adjustment model are proposed and investigated to improved the geometric performance of the experimental dataset. Based on our proposed method, 142 multi-angle GF-2 satellite images covering the western Beijing area are experimented and the root mean square error (RMSE) of the geometric accuracy is improved up to about 12m in plane and 6m in height, which shows a significantly improvement in geo-positioning accuracy of these multi-angle GF-2 remote sensing imagery.

关键词： Satellites Image resolution Mathematical model Unified modeling language Remote sensing Clustering algorithms Cameras

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A method for position offset correction of ship target on SAR image based on AIS data 5

A method for position offset correction of ship target on SA...

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IET International Radar Conference 2020, IET IRC 2020

作者： Lv, Yini Zhong, Lihua Yang, Junying Qiu, Xiaolan Yuan, XinZhe Han, Bing Ding, Chibiao Aerospace Information Research Institute Chinese Academic of Sciences Beijing China Key Laboratory of Technology in Geo-Spatial Information Processing and Application Systems Chinese Academy of Sciences Beijing China School of Electronic Electrical and Communication Engineering University of Chinese Academy of Sciences Beijing China National Satellite Ocean Application of Service Beijing China

ISBN: (纸本)9781839535635

This paper proposes a method for the ship target azimuth offset correction on the Synthetic Aperture Radar (SAR) image using Automatic Identification System (AIS) data. Traditional AIS and SAR image ship matching usually use AIS position, size, and other information. This paper uses a continuous position sequence around the SAR image acquisition time, that is, the complete trajectory, to calculate the slant range between the ship and the space-borne SAR platform. By deriving the slant range, the radial velocity can be obtained. According to the radial velocity, the azimuth offset of the moving ship is estimated to correct the ship's position on the SAR image. © 2020 Institution of Engineering and technology. All rights reserved.

关键词： Synthetic aperture radar

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