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Observations of gravity wave activity during stratospheric sudden warmings in the Northern Hemisphere

Science China(Technological Sciences) 2015年第6期58卷 951-960页

作者： JIA Yue ZHANG ShaoDong YI Fan HUANG ChunMing HUANG KaiMing GAN Quan GONG Yun School of Electronic Information Wuhan University Key Laboratory of Geospace Environment and Geodesy Ministry of Education State Observatory for Atmospheric remote sensing State Key Laboratory of Information Engineering in surveying Mapping and Remote Sensing

Arctic stratospheric sudden warming(SSW) with polar vortex displacement and splitting occurred in 2008 and 2009, respectively. The temperature profiles derived from the Constellation Observing System for Meteorology, Ionosphere and Climate(COSMIC) along with NCEP/NCAR reanalysis are used to investigate the gravity wave(GW) variations during these SSW events. Some phenomena are characterized and possible mechanisms are discussed. The GW variations during both types of SSW events shared some similarities. During the warming events, enhanced zonal mean GW amplitudes are detected. The enhancements of GW amplitudes first appeared at higher altitudes and then progressed downward during the major warming events. The downward progressions correspond well with the height variations of the zonal wind reversal, and the enhancements seem to occur at the same time with the wind reversal. The spatial variations of GWs showed evident correlation to the polar vortex. Generally, GWs were enhanced at the edge of the polar vortex where the background wind was strong, whereas the areas with the largest GW amplitudes did not always correspond with those with the strongest background wind. The differences during the two types of SSW are also noticeable. In the 2008 major event, the magnitudes of the zonal mean GW enhancements during the downward progression were relatively stable, whereas in the 2009 major event, a clear reduction was detected as the GW enhancement was progressing downward. Also, the recovery time of the polar vortex was longer in 2009. These differences indicate that different types of SSWs may have different impacts on the GW.

关键词： stratospheric sudden warming gravity wave COSMIC

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OpenRS-Cloud:A remote sensing image processing platform based on cloud computing environment

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Science China(Technological Sciences) 2010年第S1期53卷 221-230页

作者： GUO Wei,GONG JianYa,JIANG WanShou,LIU Yi & SHE Bing State Key Laboratory for Information Engineering in surveying,Mapping and remote sensing,Wuhan University,Wuhan 430074,China State Key Laboratory for Information Engineering in surveying Mapping and Remote Sensing Wuhan University Wuhan China

This paper explores the use of cloud computing for remote sensing image *** main contribution of our work is to develop a remote sensing image processing platform based on cloud computing technology(OpenRS-Cloud).This paper focuses on enabling methodical investigations into the development pattern,computational model,data management and service model exploring this novel distributed computing *** experimental INSAR processing flow is implemented to verify the efficiency and feasibility of OpenRS-Cloud *** results show that cloud computing is well suited for computationally-intensive and data-intensive remote sensing services.

关键词： remote sensing cloud computing MapReduce parallel computing web service

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Image-based self-position and orientation method for moving platform

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Science China(Information Sciences) 2013年第4期56卷 5-18页

作者： LI DeRen LIU Yong YUAN XiuXiao State Key Laboratory of Information Engineering in surveying Mapping and Remote SensingWuhan University School of Electronic Information Wuhan University School of remote sensing and Information Engineering Wuhan University

The position and orientation of moving platform mainly depends on global positioning system and inertial navigation system in the field of low-altitude surveying,mapping and remote sensing and land-based mobile mapping ***,GPS signal is unavailable in the application of deep space exploration and indoor robot *** such circumstances,image-based methods are very important for self-position and orientation of moving ***,this paper firstly introduces state of the art development of the image-based self-position and orientation method(ISPOM) for moving platform from the following aspects:1) A comparison among major image-based methods(i.e.,visual odometry,structure from motion,simultaneous localization and mapping) for position and orientation;2) types of moving platform;3) integration schemes of image sensor with other sensors;4) calculation methodology and quantity of image ***,the paper proposes a new scheme of ISPOM for mobile robot-depending merely on image *** takes the advantages of both monocular vision and stereo vision,and estimates the relative position and orientation of moving platform with high precision and high *** a word,ISPOM will gradually speed from research to application,as well as play a vital role in deep space exploration and indoor robot control.

关键词： self-position and orientation ISPOM visual odometry structure from motion simultaneous localization and mapping

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Fast registration of multisource three-dimensional city models in GeoGlobe

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International Journal of Digital Earth 2015年第4期8卷 293-311页

作者： Jing Chen Tong Zhang Shutao Dong Bingxiong Xie State Key Laboratory of Information Engineering in surveying Mapping and Remote SensingWuhan UniversityWuhanChina

We address the registration problem of multisource three-dimensional(3D)human-made buildings with remote sensing images and the earth’s surface in the context of virtual *** include fast transformation of 3D coordinates with different reference systems as well as the efficient use of original model information for rigorous and accurate model *** paper introduces a novel fast and scalable registration approach that can establish correspondences between heterogeneous external 3D city models and images/terrain surfaces of virtual globes in an efficient and accurate *** approach utilizes the projected 3D feature information of 3D city models to develop robust coordinate transformation and reliable model registration *** proposed approach builds a solid foundation for the fusion of multisource geospatial data in a united virtual globe reference *** report experimental results of online registration tasks for up to over 13K buildings in an integrated 3D virtual globe platform,namely,GeoGlobe.

关键词： registration virtual globes three-dimension city models coordinate transformation GeoGlobe

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Analysis of China Vegetation Dynamics Using NOAA-AVHRR Data from 1982 to 2001

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Geo-Spatial Information Science 2009年第2期12卷 146-153页

作者： HABIB Aziz Salim 陈晓玲龚健雅王海燕张俐 State Key Laboratory of Information Engineering in surveying Mapping and Remote Sensing Wuhan University

The authors derived the normalized difference vegetation index （NDVI） from the NOAA/AVHRR Land dataset, at a spatial resolution of 8km and 15-day intervals, to investigate the vegetation variations in China during the period from 1982 to 2001. Then, GIS is used to examine the relationship between precipitation and the Normalized Difference Vegetation Index （NDVI） in China, and the value of NDVI is taken as a tool for drought monitoring. The results showed that in the study period, China＇s vegetation cover had tended to increase, compared to the early 1980s; mean annual NDVl increased 3.8%. The agricultural regions （Henan, Hebei, Anhui and Shandong） and the west of China are marked by an increase, while the eastern coastal regions are marked by a decrease. The correlation between monthly NDVl and monthly precipitation/temperature in the period 1982 to 2001 is significantly positive （R^2 =0.80, R^2 =0.84）; indicating the close coupling between climate conditions （precipitation and temperature） and land surface response patterns over China. Examination of NDVl time series reveals two periods：（1） 1982-1989, marked by low values below average NDVI and persistence of drought with a signature large-scale drought during the 1982 and 1989; and （2） 1990-2001, marked by a wetter trend with region-wide high values above average NDVl and a maximum level occurring in 1994 and 1998.

关键词： NOAA-AVHRR NDVI temperature precipitation drought China

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Multi-source geospatial information integration and sharing in Virtual Globes

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Science China(Technological Sciences) 2010年第S1期53卷 1-6页

作者： GONG JianYa,XIANG LongGang,CHEN Jing & YUE Peng State Key Laboratory of Information Engineering in surveying,Mapping and remote sensing,Wuhan University,Wuhan 430072,China State Key Laboratory of Information Engineering in surveying Mapping and Remote Sensing Wuhan University Wuhan China

Massive volumes of global geospatial information are being collected by newly designed acquisition devices and generated by various geospatial *** poses a critical challenge to efficiently organize and effectively integrate global multi-source geospatial *** paper introduces a global seamless data model for the organization of huge multi-source,multi-resolution and multi-temporal geospatial *** on this data model,the management of the global multi-resolution pyramid is discussed in *** integrate geospatial data and processing functions from various GIS systems,a service-oriented framework is presented through the technology of Virtual ***,a Virtual Globe system,GeoGlobe,is developed and illustrated.

关键词： Virtual Globe geospatial information multi-resolution pyramid Web service GeoGlobe

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A Fast Clonal Selection Algorithm for Feature Selection in Hyperspectral Imagery

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Geo-Spatial Information Science 2009年第3期12卷 172-181页

作者：钟燕飞张良培 State Key Laboratory of Information Engineering in surveying Mapping and Remote Sensing Wuhan University

Clonal selection feature selection algorithm （CSFS） based on clonal selection algorithm （CSA）, a new computational intelligence approach, has been proposed to perform the task of dimensionality reduction in high-dimensional images, and has better performance than traditional feature selection algorithms with more computational costs. In this paper, a fast clonal selection feature selection algorithm （FCSFS） for hyperspectral imagery is proposed to improve the convergence rate by using Cauchy mutation instead of non-uniform mutation as the primary immune operator. Two experiments are performed to evaluate the performance of the proposed algorithm in comparison with CSFS using hyperspectral remote sensing imagery acquired by the pushbroom hyperspectral imager （PHI） and the airborne visible/infrared imaging spectrometer （AVlRIS）, respectively. Experimental results demonstrate that the FCSFS converges faster than CSFS, hence providing an effective new option for dimensionality reduction of hyperspectral remote sensing imagery.

关键词： hyperspectral feature selection artificial immune systems artificial intelligence

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Component-adaptive up-sampling for inter layer interpolation in scalable video coding

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Science in China(Series F) 2009年第4期52卷 704-711页

作者： WANG Zhang ZHANG JiXian LI HaiTao Institute of Photogrammetry and remote sensing Chinese Academy of Surveying and Mapping Beijing 100039 China

Scalable video coding （SVC） is a newly emerging standard to be finalized as an extension of H.264/AVC. The most attractive characters in SVC are the inter layer prediction techniques, such as Intra_BL mode. But in current SVC scheme, a uniform up-sampling filter （UUSF） is employed to magnify all components of an image, which will be very inefficient and result in a lot of redundant computational complexity. To overcome this, we propose an efficient component-adaptive up-sampling filter （CAUSF） for inter layer interpolation. In CAUSF, one character of human vision system is considered, and different up- sampling filters are assigned to different components. In particular, the six-tap FIR filter used in UUSF is kept and assigned for luminance component. But for chrominance components, a new four-tap FIR filter is used. Experimental results show that CAUSF maintains the performances of coded bit-rate and PSNR-Y without any noticeable loss, and provides significant reduction in computational complexity.

关键词： scalable video coding spatial interpolation up-sampling filter human vision system

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Design and Implementation of Service-Oriented Spatial Information Sharing Framework in Digital City

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Geo-Spatial Information Science 2009年第2期12卷 104-109页

作者：邵振峰李德仁 State Key Laboratory for Information Engineering in surveying Mapping and Remote Sensing Wuhan University

This paper proposes a theoretical framework of spatial information sharing in a digital city, and analyzes its technical characteristics. According to the service-oriented architecture (SOA) framework, a geospatial information sharing platform is put forward. The spatial information sharing model based on SOA is designed. A prototype platform realizing multiple-source spatial information sharing based on ArcGIS Server is developed.

关键词： digital city Web services service-oriented architecture (SOA) spatial information sharing

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Soil moisture estimation based on BeiDou Bl interference signal analysis

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Science China Earth Sciences 2016年第12期59卷 2427-2440页

作者： YAN SongHua ZHAO Fen CHEN NengCheng GONG JianYa School of Electronic Information Wuhan University State Key Laboratory of Information Engineering in surveying Mapping and Remote SensingWuhan University

BeiDou Navigation Satellite System reflectometry(BDS-R) is an emerging area of BD(BeiDou) applications that uses multipath reflected signals in microwave remote *** moisture estimation is one of the potential important applications of *** study aims to investigate the feasibility of soil moisture estimation based on BD B1 band interference signals,which are composed of direct and reflected BD signals and can be readily captured using low-cost commercial BDS *** this paper,a theoretical background for soil estimation from interference signals was introduced,and an analysis of field experimental data was ***,a cosine model for the interference signal power was built,and a non-uniform power spectrum analysis was performed on the received interference signals to determine its main ***,a least squares curve fitting was applied on the interference signal power to extract its *** relationship between the soil moisture and the phase was then *** months of experimental data were collected at BaoXie,Wuhan and analyzed for further *** results show that the phase of the interference signals increases with the increase of soil *** correlation coefficient between the phase and the in-situ soil moisture value is approximately ***,the relationship between the phase and soil moisture is employed to estimate soil *** show that using BDS-R to measure soil moisture is feasible,which demonstrates a great potential of new application of the BD system.

关键词： BDS-R Soil moisture estimation Interference signal Non-uniform power spectrum Least squares curve fitting SNR

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