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The paleoclimatic environment reconstruction of Lop Nur in NW China in UAV spectroscopy

Journal of Oceanology and Limnology 2023年第4期41卷 1425-1443页

作者： Lan YANG Tingting ZHANG Huaze GONG Yuyang GENG Guangjin TIAN laboratory of target microwave properties Deqing Academy of Satellite ApplicationsHuzhou 313200China Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100049China School of Government Beijing Normal UniversityBeijing 100875China

The change in the ecological environment in the arid core area is a critical issue in the context of global *** study the paleoclimate evolution,precise identification of minerals deposited in Asia’s arid hinterland,Lop Nur Salt Lake,NW China was *** hyperspectral data of the salt crust was sampled to identify the species and content of sedimentary minerals,and the multispectral photos were used to reconstruct the salt crust morphology using the unmanned aerial vehicles *** SUnSAL(sparse unmixing by variable splitting and augmented Lagrangian)method was employed to inverse the sedimentary mineral components along the *** heterogeneity of salt and clay minerals in bright and dark ear-shaped strips was *** paleoclimatic environment associated with salt lake extinction was reconstructed by analyzing paleoclimate records of sediments,spectral reflectance and morphology of the salt *** show that:(1)the variations in the micro-geomorphology of the salt crust are obviously the reason for the formation of bright and dark ear-shaped strips and the differences in the species and relative content of the sedimentary minerals are the microscopic *** high ratio of sedimentary salt minerals to clay minerals(RS/C)contributes to the high reflectivity,and the salt crust presents a bright *** low RS/C results in the low reflectivity,salt crust presents a dark texture;(2)the bright and dark ear-shaped strips represent warm-arid and cold-humid *** shape of the Lop Nur Lake shoreline evolved due to alternating warm-dry and cold-humid paleoclimate changes.

关键词： UAV remote sensing Lop Nur sparse spectral unmixing salt lake paleoclimate change

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Comparison of C- and L-band simulated compact polarized SAR in oil spill detection

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Frontiers of Earth Science 2019年第2期13卷 351-360页

作者： Xiaochen WANG Yun SHAO Fengli ZHANG Wei TIAN laboratory of target microwave properties Deqing Academy of Satellite ApplicationsHuzhou 313200China Institute of Remote Sensing and Digital Earth Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

This paper presents the compact polarized (CP) pseudo quad-pol parameters for the detection of marine oil spills and segregation of lookalikes using simulated CP SAR data from full-polarized (FP) SAR *** to the CP theory,11 polarized parameters generally used for the detection of oil spills were derived from reconstructed pseudo quad-pol data for both C and L *** addition,the reconstruction performance between C and L bands was also compared by evaluating the reconstruction accuracy of retrieved polarized *** results show that apart from(thv and RH,other polarized parameters of σHH,σVV,H,α,φH-V,r,ρH-V,and γ can be reconstructed with satisfactory accuracy for both C and L ***,C band has a higher reconstruction accuracy than L band,especially for φ***,the effect of reconstruction of polarized parameters on oil spill classification was also evaluated using the maximum likelihood classification (MLC) *** to the evaluation of kappa coefficients and mapping accuracy,it is recommended to use σHH,σVV,H,ρH-V,and γ of the C band CP SAR for marine oil spill classification.

关键词： compact polarized reconstruction oil spill classification

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A study on historical location and evolution of Lop Nor in China with maps and DEM

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Journal of Arid Land 2021年第6期13卷 639-652页

作者： ZHANG Tingting SHAO Yun GENG Yuyang GONG Huaze YANG Lan laboratory of target microwave properties Deqing Academy of Satellite ApplicationsDeqing 313200China Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100094China University of Chinese Academy of Science Beijing 100049China China University of Geosciences Beijing100083China

Lop Sea,located at the east end of the Tarim Basin,Northwest China,dried up permanently,which is the terminal lake of the Tarim *** Sea was considered as the lake basin of Lop Nor since ***,the possibility that Lop Nor was away from the Lop Sea in historical time is crucial to be discussed to interpret the proxy records in sediment *** obtain a general view of the evolution of Lop Nor and Lop Sea in a historical period,several approaches were adopted in this ***,the Qianlong Thirteen-Row Atlas,an ancient imperial atlas of the Qing Dynasty,which was completed around 1760,indicated that the Tarim River formed a relatively large lake at its modern upstream ***,a Digital Elevation Model(DEM)with a 10-m spatial resolution and a relative precision of 0.42 m was derived from TanDEM-X/Terra SAR-X satellite image pairs using the interferometry method,which was verified using ICESat-GLAS laser footprints and a local DEM acquired by a ***,based on the spatial analysis of historical documents,expedition reports,sediment profiles and archaeological evidence,it can be deduced that the lacustrine deposition was discontinued in the Lop *** episodes in the evolutionary history of the drainage system in eastern Tarim Basin were *** proved depositional condition variations could be used for future interpretation of proxy records in *** high-accurate DEM provided a reference for the location of further fieldwork in the Lop *** method proposed in this paper may be efficient for the research of inland lakes or rivers in global arid regions.

关键词： Lop Sea historical period lake basin topography TanDEM-X InSAR lacustrine deposit drainage evolution

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A newly developed ocean significant wave height retrieval method from Envisat ASAR wave mode imagery

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Acta Oceanologica Sinica 2019年第9期38卷 120-127页

作者： Chenqing Fan Xiaochen Wang Xudong Zhang Dong Gao First Institute of Oceanography Ministry of Natural Resources Qingdao 266061 China Aerospace Information Research Institute Chinese Academy of Sciences Beijing 100190 China laboratory of target microwave properties Deqing Academy of Satellite Applications Deqing 313200 China College of information and engineering Ocean University of China Qingdao 266071 China

The main objective of this paper is to propose a newly developed ocean Significant Wave Height (SWH) retrieval method from Envisat Advanced Synthetic Aperture Radar (ASAR) imagery. A series of wave mode imagery from January, April and May of 2011 are collocated with ERA-Interim reanalysis SWH data. Based on the matched datasets, a simplified empirical relationship between 22 types of SAR imagery parameters and SWH products is developed with the Genetic Algorithms Partial Least-Squares (GA-PLS) model. Two major features of the backscattering coefficient σ0 and the frequency parameter S10 are chosen as the optimal training feature subset of SWH retrieval by using cross validation. In addition, we also present a comparison of the retrieval results of the simplified empirical relationship with the collocated ERA-Interim data. The results show that the assessment index of the correlation coefficient, the bias, the root-mean-square error of cross validation (RMSECV) and the scattering index (SI) are 0.78, 0.07 m, 0.76 m and 0.5, respectively. In addition, the comparison of the retrieved SWH data between our simplifying model and the Jason-2 radar altimeter data is proposed in our study. Moreover, we also make a comparison of the retrieval of SWH data between our developed model and the well- known CWAVE_ENV model. The results show that satisfying retrieval results are acquired in the low-moderate sea state, but major bias appears in the high sea state, especially for SWH>5 m.

关键词： significant wave height Envisat ASAR GA-PLS optimal feature subset

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A point cloud segmentation method for power lines and towersbased on a combination of multiscale density features andpoint-based deep learning

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International Journal of Digital Earth 2023年第1期16卷 620-644页

作者： Wenbo Zhao Qing Dong Zhengli Zuo Key laboratory of Digital Earth Science Aerospace Information Research InstituteChinese Academy of SciencesBeijingPeople’s Republic of China International Research Center of Big Data for Sustainable Development Goals BeijingPeople’s Republic of China University of Chinese Academy of Sciences BeijingPeople’s Republic of China laboratory of target microwave properties Deqing Academy of Satellite ApplicationsZhejiangPeople’s Republic of China

The point segmentation of power lines and towers aims to use unmanned aerial vehicles(UAVs)for the inspection of power facilities,risk detection and *** of the unclear spatial relationship between the point clouds,the point segmentation of power lines and towers is *** this paper,the power line and tower point datasets are constructed using Light Detection and Ranging(LiDAR)and a point segmentation method is proposed based on multiscale density features and a point-based deep learning ***,the data are blocked and the neighbourhood is ***,the point clouds are downsampled to produce sparse point *** point clouds before and after sampling are rotated,and their density is ***,a direct mapping method is selected to fuse the density information;a lightweight network is built to learn the ***,the point clouds are segmented by concatenating the local features provided by *** algorithm performs effectively on different types of power lines and *** mean interaction over union is 82.73%,and the overall accuracy can reach 91.76%.This approach can achieve the end-to-end integration of segmentation and provide theoretical support for the segmentation of large scenic point clouds.

关键词： Power lines and power towers point cloud segmentation multiscale density features PointCNN

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Antireflection properties and solar cell application of silicon nanoscructures

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Journal of Semiconductors 2011年第8期32卷 55-60页

作者：岳会会贾锐陈晨丁武昌武德起刘新宇 Key laboratory of microwave Devices and Integrated Circuits Institute of MicroelectronicsChinese Academy of Sciences

Silicon nanowire arrays（SiNWAs） are fabricated on polished pyramids of textured Si using an aqueous chemical etching *** silicon nanowires themselves or hybrid structures of nanowires and pyramids both show strong anti-reflectance abilities in the wavelength region of 300-1000 nm,and reflectances of 2.52%and less than 8%are achieved,respectively.A 12.45%SiNWAs-textured solar cell（SC） with a short circuit current of 34.82 mA/cm^2 and open circuit voltage（K_（oc）） of 594 mV was fabricated on 125×125 mm^2 Si using a conventional process including metal grid *** is revealed that passivation is essential for hybrid structure textured SCs,and K_（oc） can be enlarged by 28.6%from 420 V to 560 mV after the passivation layer is *** loss mechanism of SiNWA SC was investigated in detail by systematic comparison of the basic parameters and external quantum efficiency（EQE） of samples with different fabrication *** is proved that surface passivation and fabrication of a metal grid are critical for high efficiency SiNWA SC,and the performance of SiNWA SC could be improved when fabricated on a substrate with an initial PN junction.

关键词： antireflection properties silicon nanowires solar cells passivation

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Building damage mapping based on Touzi decomposition using quad-polarimetric ALOS PALSAR data

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Frontiers of Earth Science 2020年第2期14卷 401-412页

作者： Shan LIU Fengli ZHANG Shiying WEI Qingbo LIU Na LIU Yun SHAO Steven JBURIAN Institute of Remote Sensing and Digital Earth Chinese Academy of Sciences Beijing 100094China University of Chinese Academy of Sciences Beijing 100049China laboratory of target microwave properties Deqing Academy of Satellite ApplicationsHuzhou 313200China Beijing University of Civil Engineering and Architecture Beijing 100044China Department of Civil and Environmental Engineering University of UtahSalt Lake CityUT 84112USA

Building damage assessment is of great significance to disaster *** Synthetic Aperture Radar(SAR)can record the polarization scattering measurement matrix of ground objects and obtain more abundant ground object information,meaning that they can be used for assessing damage to *** this paper,a new approach is proposed to assess building damage using the Touzi incoherent decomposition and SAR-based characteristics of buildings before and after *** March 11th,2011 earthquake that struck the coast of northeast Japan serves as the demonstration of the technique using quad-polarimetric ALOS PALSAR data acquired before and after the *** analysis shows that after the buildings are damaged,there is a clear decrease in theαs1(the dominant scattering-type magnitude)components and the degree of this reduction corresponds to the degree of building *** means that theαs1 components obtained by Touzi decomposition can effectively reflect the degree of building *** this basis,a model based on Touzi decomposition was established to evaluate the degree of damage to buildings,and the accuracy of the model was validated using high-resolution optical data acquired before and after the *** experimental results show that Touzi decomposition can be effectively used for damage assessment mapping in built-up areas.

关键词： Touzi decomposition quad-polarization SAR buildings damage disaster management

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Equivalent system model for the calibration of polarimetric SAR under Faraday rotation conditions

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Science China(Information Sciences) 2018年第2期61卷 36-49页

作者： Jingjing ZHANG Wen HONG Science and Technology on microwave Imaging laboratory Institute of ElectronicsChinese Academy of Sciences University of Chinese Academy of Sciences

An equivalent system model(ESM) that can be used to calibrate a SAR system affected by both the effect of system errors and the Faraday rotation(FR) is proposed. This ESM contains only systemdistortion-like parameters but includes a distortion matrix(DM) that is identical to the original, which contains the effects of both the system errors and the Faraday rotation angle(FRA). With this model, the conventional distributed-target-based(DT-based) algorithms which have not taken FR effect into account are readily applicable. The conditions on FRA for the successful application of DT-based algorithms are studied, and the results suggest that reliable estimates can be obtained for a well-designed system whose true system crosstalk level is lower than-20 d B provided that the mean FRA at the calibration site is within±15? and that the FRA can be suitably modeled as Gaussian. Thus, the requirements on the crosstalk level or the FRA that are commonly employed in other calibration methods designed for data affected by FR are relaxed.

关键词： calibration Faraday rotation(FR) polarimetry distibuted target(DT) synthetic aperture radar(SAR)

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Hardware-in-the-loop simulation technology of wide-band radar targets based on scattering center model

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Chinese Journal of Aeronautics 2015年第5期28卷 1476-1484页

作者： Huang Hao Pan Minghai Lu Zhijun Key laboratory of Radar Imaging and microwave Photonics Ministry of Education Nanjing University of Aeronautics and Astronautics Shanghai Key laboratory of Space Intelligent Control Technology

Hardware-in-the-loop （HWIL） simulation technology can verify and evaluate the radar by simulating the radio frequency environment in an anechoic chamber. The HWIL simulation technology of wide-band radar targets can accurately generate wide-band radar target echo which stands for the radar target scattering characteristics and pulse modulation of radar transmitting signal. This paper analyzes the wide-band radar target scattering properties first. Since the responses of target are composed of many separate scattering centers, the target scattering characteristic is restructured by scattering centers model. Based on the scattering centers model of wide-band radar target, the wide-band radar target echo modeling and the simulation method are discussed. The wide-band radar target echo is reconstructed in real-time by convoluting the transmitting signal to the target scattering parameters. Using the digital radio frequency memory （DRFM） system, the HWIL simulation of wide-band radar target echo with high accuracy can be actualized. A typical wide-band radar target simulation is taken to demonstrate the preferable simulation effect of the reconstruction method of wide-band radar target echo. Finally, the radar target time-domain echo and high-resolution range profile （HRRP） are given. The results show that the HWIL simulation gives a high-resolution range distribution of wide-band radar target scattering centers.

关键词： Digital radio frequencymemory Error analysis Hardware-in-the-loop simu-lation Radar targets Scattering parameters

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A new and promising application of gene editing: CRISPR-controlled smart materials for tissue engineering,bioelectronics, and diagnostics

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Science China(Life Sciences) 2019年第11期62卷 1547-1549页

作者： Weiqi Hong Mengyuan Huang Yuquan Wei Xiawei Wei laboratory of Aging Research and Cancer Drug target State Key Laboratory of BiotherapyNational Clinical Research Center for GeriatricsWest China HospitalSichuan University

A recent study published in the journal Science by Collins et *** a programmable clustered regularly interspaced short palindromic repeats(CRISPR)-responsive smart material containing the CRISPR-associated nuclease,Casl2a,and hydrogels containing DNA to deliver biological information via changes in material properties(English et al.,2019).

关键词： CRISPR smart journal

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