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REVERSE-RANGE-DOPPLER METHOD FOR AUTOMATED geoCODING SAR IMAGES

Journal of Electronics(China) 2012年第3期29卷 242-247页

作者： Liu Jiayin Hong Wen Key Laboratory of Technology on Geo-spatial Information Processing and Application System Chinese Academy of SciencesBeijing 100190China National Key Laboratory of Microwave Imaging Technology Beijing 100190China Institute of Electronics Chinese Academy of SciencesBeijing 1001q0China

Range-Doppler (RD) method and Reverse-Range-Doppler (RRD) method are combined together to achieve automatic geocoding of Synthetic Aperture Radar (SAR) image quickly and accurately in the paper. The RD method is firstly used to locate the four corners of the image, then the other pixels of the image can be located by Reverse-Range-Doppler (RRD) method. Resampling is performed at last. The approach has an advantage over previous techniques in that it does not require ground control points and is independent of spacecraft attitude knowledge or control. It can compensate the shift due to the assumed Doppler frequency in SAR image preprocessing. RRD simplifies the process of RD, therefore speeds up the computation. The experimental results show that a SAR image can be automated geocoded in 30 s using the single CPU (3 GHz) with 1 G memory and an accuracy of 10 m is attainable with this method.

关键词： Range-Doppler (RD) Reverse-Range-Doppler (RRD) geolocation Automated geocoding Space-borne Synthetic Aperture Radar (SAR)

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Automatic Extraction of Supraglacial Lake using SAR Imagery and Deep Learning

Automatic Extraction of Supraglacial Lake using SAR Imagery ...

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2021 CIE International Conference on Radar, Radar 2021

作者： Di, Jiang Xinwu, Li Chen, Gong Wen, Hong Yirong, Wu Aerospace Information Research Institute Chinese Academy of Sciences University of Chinese Academy of Sciences Beijing China Chinese Academy of Sciences Key Laboratory of Technology in Geo-spatial Information Processing and Application System Beijing China

ISBN: (纸本)9781665498142

Supraglacial lake plays an important role in ice sheet dynamics, mass balance and sea level rise. Therefore, it is of great importance to extract supraglacial lake and obtain its spatial-temporal distribution or change. This study provides an automatic extraction model for supraglacial lake, using Synthetic Aperture Radar (SAR) imagery based on deep learning. First, select 19580 Sentinel-1 SAR imagery patches in eight typical areas for manual labeling. Second, the GPU-based U-Net model is used to implement the training of the supraglacial lake, and the results are evaluated in different sites. Finally, the training model is used to perform the supraglacial lake extraction. In addition, this article also introduces ArcticDEM to remove shadow confusion in the margin of the ice sheet. The global-local threshold segmentation method is used to extract the supraglacial lake on the Sentinel-2 MSI imagery, which is a comparative analysis and information supplement for the extracted results in this paper. The results show that: (1) The U-Net network selected in this paper is suitable for processing small sample size SAR data and multi-modal feature extraction. The GPU parallel processing method can achieve rapid extraction of massive data and reduce time cost. (2) The Dice coefficient of the training model reaches 0.98, which can be used for effective extraction of supraglacial lake. (3) Compared with the results of optical image extraction, the algorithm proposed in this paper can identify lakes in areas covered by snow or thin ice, which truly reflects the supraglacial lake temporal and spatial distribution characteristics. © 2021 IEEE.

关键词： Greenland SAR Supraglacial lake U-Net

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Improved calibration method of the airborne polarimetric SAR

Improved calibration method of the airborne polarimetric SAR

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2011 3rd International Asia-Pacific Conference on Synthetic Aperture Radar, APSAR 2011

作者： Ming, Feng Hong, Jun Zhang, Lintao Institute of Electronics Chinese Academy of Sciences Beijing 100190 China Key Laboratory of Geo-spatial Information Processing and Application System Technology CAS Beijing 100190 China National Key Laboratory of Microwave Imaging Technology Beijing 100190 China Graduate University of the Chinese Academy of Sciences Beijing 100039 China

ISBN: (纸本)9788993246179

The PolSAR system must be calibrated before obtain effective polarimetric information. The airplane attitude is unstable during the PolSAR measurement, which will impact the polarimetric calibration precision. This paper improved the polarimetric calibration method proposed by Whitt considering the impact of airplane attitude. The improved method is proved by polarimetric experiment using a PolSAR system developed by IEcas(Institute of electronics, Chinese Academy of Sciences). © 2011 KIEES.

关键词： Calibration

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A general two-dimensional spectrum based on polynomial range model for Medium-Earth-Orbit Synthetic Aperture Radar signal processing

A general two-dimensional spectrum based on polynomial range...

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2010 2nd International Conference on Signal Processing systems, ICSPS 2010

作者： Huang, Lijia Hu, Donghui Ding, Chibiao Qiu, Xiaolan Key Laboratory of Geo-spatial Information Processing and Application System Technology Beijing China Institute of Electronics Chinese Academy of Sciences Beijing China Graduate University Chinese Academy of Sciences Beijing China

ISBN: (纸本)9781424468911

The kth-order polynomial range model (PRM) for Medium-Earth-Orbit (MEO) Synthetic Aperture Radar (SAR) signal processing is proposed, analyzed, and verified in this paper. The coefficients of the PRM are calculated according to the relative state vectors between the satellite and the given target on earth, which implies power series expansion around the beam center crossing time. In addition, the relevant two-dimensional spectrum is deduced out as well by using the principle of stationary phase (POSP) and the series reversion approximation. The accuracy of this spectrum is flexible and limited both by the order of the PRM and the order of the spectrum in an expanded form. Therefore, the PRM-based spectrum is general for MEO SAR with any azimuth resolution at any orbit height. © 2010 IEEE.

关键词： Synthetic aperture radar

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A new fusion algorithm for optical remote sensing data

A new fusion algorithm for optical remote sensing data

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2011 International Symposium on Image and Data Fusion, ISIDF 2011

作者： Yu, Kai Hu, Ni Geng, Xiurui Zhao, Yongchao Tang, Hairong Key Laboratory of Technology in Geo-spatial Information Processing and Application System Institute of Electronics Chinese Academy of Science China Patent Examination Cooperation Center of State Intellectual Property Office 100190 China

ISBN: (纸本)9781457709692

The main goal of data fusion in remote sensing is integrating the respective superiority and complementary information of multi-source data to serve the applications. Most conventional fusion algorithm is oriented to fuse the multispectral (hyperspectral) data with panchromatic data such as IHS fusion, PCA fusion, DWT fusion, Brovey fusion etc. Although these methods have been widely used, they still have a problem that can't maintain the spatial information and spectral information synchronously. In this study, a new fusion algorithm aiming at fusing multispectral data and hyperspectral data was developed in following steps: First, classify the hyperspectral data into groups basing on the wavelength range of each multispectral band;second, process each band group by PCA, and combine all the first components to a new multispectral data;then, separate each original multispectral pixel by the homologous pixel and its eight neighbor pixels in the new multispectral data;Finally, mix the homologous 9 pixels of hyperspectral data by the abundance got by former step. The applying on AVIRIS data 'cuprite' brought by ENVI shows an excellent result and verified the validity. © 2011 IEEE.

关键词： Pixels

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geostationary autonomous trajectory determination technology based on enhanced inter-satellite links of the Beidou medium earth orbit constellation

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Aerospace Science and technology 2025年 163卷

作者： Jiao, Fangtan Hu, Yuxin Yu, Xiaodong Wang, Haihong Chen, Qiuli Aerospace Information Research Institute Chinese Academy of Sciences Beijing 100094 China Key Laboratory of Geo-spatial Information Processing and Application System Technology Chinese Academy of Sciences Beijing100190 China University of Chinese Academy of Sciences Beijing100049 China School of Electronic Electrical and Communication Engineering University of Chinese Academy of Sciences Beijing100049 China Institute of Telecommunication and Navigation Satellite CAST Beijing100094 China

Trajectory determination is critical for autonomous operations in geostationary Orbit (geo). However, the existing methods cannot satisfy the need for stability and accuracy in short-cycle scenarios. Since the emerging method based on the Ka-band Inter-Satellite Link (ISL) of the Beidou satellite navigation system medium Earth orbit constellation has the advantages of high accuracy and anti-interference, this paper applies it to the autonomous operations of geo satellites and analyzes the feasibility and link characteristics. Different from previous ISL-related studies about long-term orbit determination, there is an issue of periodic failure of priori orbital data caused by frequent maneuvers in short-cycle autonomous operations for ISL-based applications. In this paper, by fusing the priori clock bias information and multiple ISL observation data under the constraint of a sub-hour period, we propose an ISL-based fractional steps filtering method containing rapid contraction and precise tracking, assisted by an optimized satellite selection strategy, to address the issue above. The result indicates that thanks to an average number of 12.16 visible navigation satellites for geo users, the proposed method with dispersed and diversified satellite selection scheme gives excellent results, with convergence to sub-meter accuracy in 10 min on average that satisfies the constraint of a sub-hour period and shows a 41.1 % improvement in average convergence time efficiency compared to the traditional method. Moreover, regarding trajectory determination accuracy in short-cycle autonomous operations, the root-mean-square error achieves about 0.38 m, which is better than the result of existing applications of about 10–20 m precision, demonstrating the advantages of the proposed method. © 2025 Elsevier Masson SAS

关键词： geostationary satellites

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Perceptual Evaluation of Pre-processing for Video Transcoding

Perceptual Evaluation of Pre-processing for Video Transcodin...

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IEEE Visual Communications and Image Processing (VCIP)

作者： Shiyu Huang Ziyuan Luo Jiahua Xu Wei Zhou Zhibo Chen CAS Key Laboratory of Technology in Geo-spatial Information Processing and Application System University of Science and Technology of China Hefei China

ISBN: (纸本)9781728173221

Recently, the pre-processed video transcoding has attracted wide attention and has been increasingly used in practical applications for improving the perceptual experience and saving transmission resources. However, very few works have been conducted to evaluate the performance of pre-processing methods. In this paper, we select the source (SRC) videos and various pre-processing approaches to construct the first Pre-processed and Transcoded Video Database (PTVD). Then, we conduct the subjective experiment, showing that compared with the video sent to the codec directly at the same bitrate, the appropriate pre-processing methods indeed improve the perceptual quality. Finally, existing image/video quality metrics are evaluated on our database. The results indicate that the performance of the existing image/video quality assessment (IQA/VQA) approaches remain to be improved. We will make our database publicly available soon.

关键词： Measurement Codecs Databases Visual communication Image processing Buildings Bit rate

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caspatch: A SAR image simulation code to support ATR applications

CASpatch: A SAR image simulation code to support ATR applica...

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2009 Asia-Pacific Conference on Synthetic Aperture Radar, APSAR 2009

作者： Zhang, Rui Hong, Jun Ming, Feng Key Laboratory of Spatial Information Processing and Application System Technology CAS China Institute of Electronics Chinese Academy of Sciences Beijing China Graduate University of the Chinese Academy of Sciences Beijing China

ISBN: (纸本)9781424427314

In this paper, A SAR image simulation code of 3D complex targets named caspatch is introduced. This code is based on the high frequency technique of shooting and bouncing rays (SBR). The original purpose to design the code is for SAR automatic target recognition (ATR) applications, but it can also be used for RCS prediction and high resolution range profile (HRRP) generation. A GB-SAR indoor experiment is used to validate the caspatch system. The simulation results of complex targets show that high resolution, full polarimetry and wide bandwidth SAR images can be obtained via caspatch, which means our code can support multiple SAR ATR applications. What's more, an improved PolSAR ATR algorithm is also proposed in this paper. The full PolSAR ATR experiment based on simulated data is firstly reported in this paper, and higher recognition rate is achieved comparing with the single PolSAR result. ©2009 IEEE.

关键词： Synthetic aperture radar

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AutoDerain: Memory-efficient Neural Architecture Search for Image Deraining

AutoDerain: Memory-efficient Neural Architecture Search for ...

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IEEE Visual Communications and Image Processing (VCIP)

作者： Jun Fu Chen Hou Zhibo Chen CAS Key Laboratory of Technology in Geo-spatial Information Processing and Application System University of Science and Technology of China Hefei China

ISBN: (纸本)9781728173221

Learning-based image deraining methods have achieved remarkable success in the past few decades. Currently, most deraining architectures are developed by human experts, which is a laborious and error-prone process. In this paper, we present a study on employing neural architecture search (NAS) to automatically design deraining architectures, dubbed AutoDerain. Specifically, we first propose an U-shaped deraining architecture, which mainly consists of residual squeeze-and-excitation blocks (RSEBs). Then, we define a search space, where we search for the convolutional types and the use of the squeeze-and-excitation block. Considering that the differentiable architecture search is memory-intensive, we propose a memory-efficient differentiable architecture search scheme (MDARTS). In light of the success of training binary neural networks, MDARTS optimizes architecture parameters through the proximal gradient, which only consumes the same GPU memory as training a single deraining model. Experimental results demonstrate that the architecture designed by MDARTS is superior to manually designed derainers.

关键词： Training Visual communication Image processing Memory architecture Neural networks Graphics processing units

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Saliency & structure preserving multi-operator image retargeting

Saliency & structure preserving multi-operator image retarge...

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International Conference on Acoustics, Speech, and Signal Processing (IcasSP)

作者： Lingling Zhu Zhibo Chen Xiaoming Chen Ning Liao University of Science and Technology of China CAS Key Laboratory of Technology in Geo-spatial Information Processing and Application System Hefei China

ISBN: (纸本)9781479999897

Content-aware image retargeting has attracted substantial research interests in the related research community. However, so far there is still no method can preserve important image contents and structure well without introducing deformation. To address this problem, we propose a Saliency & Structure Preserving Multi-operator (SSPM) method. SSPM classifies images into three categories utilizing SIFT density to improve performance of saliency preservation, helping to mitigate negative influence from center-bias property of most existing saliency detection models. SSPM also employs different principles to improve structure preservation performance, including Earth Mover's Distance (EMD) and Gray-Level Cooccurrence Matrix (GLCM) to get optimal operator sequences for smart content-aware image retargeting. SSPM method not only can well preserve salient contents and structure, but also can greatly improve deformation resilience. Experimental results demonstrated that our method outperforms state-of-art image retargeting methods.

关键词： Distortion Feature extraction Resilience Earth Loss measurement Visualization Visual perception

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