Table of Content

20 March 2009, Volume 45 Issue 2

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3D Forward and Inversion Problems of Borehole-to-Surface Electrical Method

KE Ganpan,HUANG Qinghua

2009, 45(2):  264-272. 

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After simplifying the borehole-to-surface electrical problem as a model with a vertical line source, the authors achieved 3D resistivity forward modeling of a vertical line source of electrical current using finite element method (FEM). The authors also achieved 3D resistivity inversion on the basis of iterative nonlinear damped least square method. Some simplified models were adopted to test both the forward and the inversion algorithms. The authors used “synthetic data” obtained from the forward modeling to inverse the target resistivity in the model. The authors also investigated the possible effects of data surveying region and noises on the inversion quality of target resistivity. This study would provide some theoretical background for enhancing the quality of inversion problem of borehole-to-surface electrical method.

Aircraft Observation of Aerosol Distribution in Beijing Urban Boundary Layer during Falltime

HUANG Haiyan,FANG Wen,ZHENG Guoguang

2009, 45(2):  273-278. 

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Aerosol data sampled with the passive cavity aerosol spectrometer probe (PCASP) of airborne Particle Measurement System (PMS) in different atmospheric conditions during September in 2004 over Beijing are analyzed. The results show that the number concentration of aerosol in the south of Beijing is higher than that in the north, and different atmospheric conditions, such as temperature inversion, wind speed have important effects on the distribution of aerosol at different altitudes.

Lower Ordovician Reefs in the Honghuayuan Formation at Dongzhi, Anhui: Microbial Reefs Just Prior to the Ordovician Biodiversification

CAO Jun,LIU Jianbo,EZAKI Yoichi,ADACHI Natsuko

2009, 45(2):  279-288. 

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Morphological and ecological diversity of organisms increased during the global Great Biodiversification Event from the late Early Ordovician. Those changes were accompanied with a marked declines in microbial reefs in the subtidal settings. The reefs were built by benthic microbes, Calathium, and lithistid sponges in the middle Early Ordovician Honghuayuan Formation of Jianxin, Anhui Province. The reefs exhibit three main rock types: 1) massive skeletal grainstones， 2) lithistid sponge Calathium-microbial bindstones, and 3) microbial boundstones. Girvanella, one of representative calcimicrobes, is classified into four categories in the reefs: 1) dispersed, 2) encrusting, 3) forming into intraclasts, and 4) infilling within sponges. These types of Girvanella play a significant frame-building role in the Calathium/ lithistid sponge- microbial reefs of the Honghuayuan Formation. Such kind of microbial reefs commonly occur in the Yangtze Platform and elsewhere in the world just prior to the first acme ofthe Ordovician biodiversification. Metazoan competitions with microbes might be closely related to marked declines in microbial sediments decline after the deposition of the microbial reefs of the Honghuayuan Formation.

Microbialites in the Middle Cambrian Qinjiamiao Group in Xingshan, Hubei Province: Implication for Paleoenvironmental Reconstruction

DANG Haowen,LIU Jianbo,YUAN Xinpeng

2009, 45(2):  289-298. 

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Abundant microbialites, from the Middle Cambrian Qinjiamiao Group in the Gudongkou section near Xingshan County of Hubei Province, south China, were described in detail by macro- and microscopic observations. The microbialites in the Qinjiamiao Group consist of a great amount of stromatolites and minor thrombolites, and contain some distinguishable filamentous fossils of Girvanella. The relationship between Girvanella filaments and sediment particles strongly suggests that the microbialites in the Qinjiamiao Group were formed by microbial mats trapping and binding of carbonate sediment and the calcification of Girvanella filaments. The morphologic and structural patterns of the microbialites and associated sedimentary features argue that these microbialites were deposited in the deep to shallow subtidal settings. The Middle Cambrian Microbialites Resurgence Event, distinguished from the Qinjiamiao Group in Yangtze Platform and elsewhere in the world, might be controlled by virtually barren of metazoan, and could be recognized as a performance of the unique stutter-step transitional interval from Proterozoic stromatolitic-thrombolitic reefs to Phanerozoic metazoan-dominated reefs.

Research on Map-Matching Algorithm Oriented Navigation and Monitor

CHEN Jia,HU Jihua,ZHANG Feizhou

2009, 45(2):  299-305. 

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On the basis of introduction of map-matching problem and the uncertainty of the vehicle location information from the sensor, a real-time map-matching algorithm based on the curve-fitting and quasi-projection is put forward. By introducing isolated point tracking and GPS point of defection filtering, restriction caused by half-baked/incomplete GIS map database and errors in coordinate conversion can be eliminated. This algorithm may reduce operation complexity，and can run normally with incomplete GIS map data and partial traffic network data defections, which has better adaptability in real-time vehicle supervision and navigation system. The experimental results of the practical runs show that the new algorithm has good robustness and real-timeness.

A Hierarchical Segmentation Method for Multispectral Imagery

GUO Jiancong,LI Peijun,XIAO Xiaobai

2009, 45(2):  306-310. 

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A hierarchical segmentation method is proposed for multispectral imagery by combining extended watershed transform and dynamics of contours. First, the gradient magnitude of an image is computed, and then local irrelevant minima are eliminated. After computing dynamics of contours, hierarchical (multi-level) segmentation results are produced by thresholding. The proposed method is evaluated with a high spatial resolution image of the urban area, and compared with the existing image segmentation method. The results show that the method can get hierarchical segmentation results, and segmente most of image objects. The segmentation results give the hierarchical representation of land cover types, which is helpful for further object based analysis.

Temporal and Spatial Variation of LUCC Driving Forces on the Edge of Metropolis： A Case Study of Changping District

MENG Jijun,YAN Fen

2009, 45(2):  311-318. 

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Based on the land-use maps and socio-economic statistical data, the combination of qualitative and quantitative analysis, together with the integration of spatial and temporal analysis were used to analyze the driving forces of Changping district, Beijing, in 1996-2004. By spatial analysis, three kinds of driving factors including natural factors, population factors and economic development factors were selected. The logistic regression concludes the following. First, the increments of non-agricultural population, the production value of the second industry class, and the distance from rivers are the main driving forces of the conversion from arable land to construction land. Second, the interchanges between different types of agricultural land are mainly influenced by natural factors, such as gradient, altitude and distance from river. Third, the city expansion and variety of industry distribution are worthy of more attention when considering interchanges of different construction land. Last, socio-economic factors play more important role in the conversion from arable land to construction land and are overwhelmed by natural factors for the opposite conversion. By temporal analysis, the population increase, economy development and relative policies have great influences on land use change through qualitative analysis. A positive logarithm correlation coefficient is acquired between the construction land areas and GDP, while a negative one between arable land areas and non-agricultural population. The policy aiming to adjustment of agriculture structure promote the conversion from arable land to garden and forest land, meanwhile, the conversion from arable, garden, country resident land to spare land is driven by the arable land withdrawal policy.

Regional Responses of Sustainable Development to Flood Hazards

SUN Liying,HUANG Zheng,LIU Yongwei,NI Jinren

2009, 45(2):  319-326. 

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Rapid assessment approach is applied to the flood hazard and sustainable development in China based on specified multi-layer indicator systems using county level administrative region as mapping units. According to the interrelationships of flood hazard and sustainable development index, a new classification system is used to map China into four regions. The regional differences of the flood hazard impacts on the sustainable development in these four zones are discussed. Moreover, each zone is further classified into several sub-zones. The characteristics of major and typical counties (cities) are further discussed based on statistics of counties (cities) in different sub-zones.

Research on Comprehensive Assessment Methods for Ecological Security of Lakes and Reservoirs

MAO Feng,LI Xiaoyang,ZHANG Andi,ZHU Gaohong

2009, 45(2):  327-332. 

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Being centre on the ecosystem of lakes and reservoirs, based on the assessment of pressure of human activities, the ecological health of the lake and the service functions of the lake, a method system of comprehensive assessment of ecological security is proposed through rigorous theoretical derivation and model construction. Subsequently, the rationality and reliability of this method system are confirmed by the assessment of ecological security of Taihu Lake in China.

On the Mathematical Form, Dimension, and Locality of the Spatial Interaction Model

CHEN Yanguang

2009, 45(2):  333-338. 

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The spatial interaction models (SIMs) in geography are developed by using the ideas from fractals and spatial complexity, and three pending questions are answered. Firstly, based on the supposition that the distance cost exhibits a logarithmic growth instead of a linear growth, the impedance function of Wilson's spatial interaction model is converted from a negative exponential expression into an inverse power law. The contradiction of locality to action at a distance of SIM is thus avoided through this revision. Secondly, the inverse power law based gravity model is gotten out of the dimensional dilemma with the concept of fractal dimension. Geographical gravity measure is consequently made more understandable. Thirdly, the notion from symmetry based on the nonlinear dual programming of spatial interaction is employed to reveal the essence of entropy maximizing process of human geographical systems. The relationship between entropy maximization and structural optimization is brought to light for geographical analysis. The distinction and connection between the gravity model originating from the analogy with the law of universal gravitation and Wilson's spatial interaction model is discussed, and the similarities and differences are compared between the exponential function based and the power law based SIMs.

The Role of Amygdala in Emotional Memory： Evidence from Neuroimaging Studies

YANG Jiongjiong,ZHAO Yanbing

2009, 45(2):  355-361. 

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Emotional memory has been extensively investigated using functional neuroimaging techniques. These studies extend the understanding of the neural mechanisms of emotional memory, which were assessed mainly in animals. The authors reviewed recent studies of encoding and retrieval processes of emotional memory. These studies show evidence that the amygdala participates in emotional memory not only in the stage of consolidation, but also in the early stage of encoding, and the stage of retrieval. The correlation and connectivity analysis showed evidence for the interaction between the amygdala and the medial temporal lobe (MTL) in both encoding and retrieval stages. Recent studies suggest that stimulus category is also involved in modulation of emotional memory. The amygdala is involved in the processing of stimulus category, vividness and feeling of remembering for emotional memory. It is necessary to combine different types of techniques to explore the neural mechanisms of emotional memory in future.

Deriving Topological Relations between Uncertain Regions from Direction Relations

GUO Luo,DU Shihong,WANG Qiao

2009, 45(2):  339-349. 

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The model, regions with broad boundaries, is used to represent uncertain regions. Then, the topological and direction relations between regions with broad boundaries are represented as the combinations of relations associated with crisp regions. By relating direction-relation matrix, representing direction relations, to the extended 9-intersection model, describing topological relations, three approaches are presented to derive topological relations from direction relations between regions with broad boundaries. These approaches can be used to obtain directly topological relations from direction relations. As the approaches can avoid geometric computation, they can improve the efficiency of computing and storing topological relations.

Effects of Pubertal and Adult Social Isolation on the Latent Inhibition of Rats

JIN Jian,WANG Weiwen,MENG Qingxuan,LIU Mei,SHAO Feng

2009, 45(2):  350-354. 

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The present study investigated the effects of pubertal and adult social isolation on latent inhibition of rats and explored its dopamine substrate. In experiment 1, Wistar male rats were given 14 days isolated rearing during their puberty (PND38-51), then latent inhibition (LI) was tested in both adolescent and young adult rats, the results show that social isolation during peri-puberty impaired LI of young adult rats, but left LI of adolescent rats intact; In experiment 2, Wistar male rats were given 14 days isolated rearing during their puberty (PND58-71), then LI was tested at PND72 and PND86, the results show that social isolation during adult period did not affect LI of rats; In experiment 3, after the same isolation treatment like experiment 1, dopamine (DA) level in nucleus accumbens (NAc) was measured in adolescent and young adult rats, the results showed that social isolation during puberty increased the DA level of NAc in young adult rats, but not in adolescent rats. These results suggest that compared to social isolation during adult period, the expression of LI deficit induced by isolated rearing during puberty is found after a developmental delay, and DA in NAc may be involved in the neural substrate, which may mirror some aspects of the ontogency of schizophrenic symptoms.

Dependence of Image Resolution on the Air Hole Shape for 2D Photonic Crystal Slab Lens

SONG Yi,WANG Ruopeng

2009, 45(2):  362-364. 

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The authors analyzed the dependence of resolution of the image formed by this kind of slab lens by using the finite-difference time-domain (FDTD) method. The numerical results show that the subwavelength image resolution can be obtained, and the resolution is of the same order as the crystal constant. It is found that the image resolution depends on the symmetry of the air hole, and the higher symmetry corresponds to the better resolution. The 2D photonic crystal slab lens with circular air hole has best image resolution.

Identification of Puny Polar Components of the Flower of?Gentiana siphonantha in Tibet by GC-MS

SHEN Jie,YE Yunhua,ZHANG Xiu,ZHOU Yawei

2009, 45(2):  365-370. 

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Puny polar components of Gentiana siphonantha are analyzed by GC-MS for the first time. The dried flower of G.siphonantha is extracted by the reflux of ethanol; the residue is suspended in water and extracted successively with different boiling range petroleum ether respectively. Alkanes are main component in two different extractions before esterification detected by GC-MS，and four aromatic esters exist with the high content in the petroleum ether (60-90℃) fractions before esterification. Thirty compounds are identified from two different etherifications by GC-MS. Fatty acids are one of the main components，which the contents of 14-methyl-pentadecanoic acid，9，12-octadecadienoic acid and 9，12，15-octadecatrienoic acid are high. The results would provide important foundation for understanding the constituents and further exploitation of Gentiana siphonantha.

A Current-Sensing Circuit with High Accuracy and Fast Response

JIANG Mei,WANG Xin'an,MA Xinwen,ZHANG Xing

2009, 45(2):  204-208. 

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A current-sensing circuit using senseFETs as current sensing devices in a current mode PWM DC-DC Converter system is presented.It is easy to be integrated because of the simple structure and it owns excellent frequency response, low power dissipation.The accuracy of this circuit is high in a wide range of the load current，and it will be elevated with the using of the cascade-common-gate amplifiers' structure.The test chip is fabricated in CSMC 0.5 μm 2p3M 3.3 V CMOS process.The measurement results show that the buck converter can operate from 1.2 to 2 MHz with supply voltage from 2.5 to 5.5 V for lithium ion battery application，and the output voltage is 1.5 V.The highest accuracy of proposed current sensing circuit is 97.75% for the load current from 50 to 600 mA.

Relation between Collins Moment and Feynman Variable

CHENG Erkang,MAO Yajun

2009, 45(2):  195-198. 

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Collins moment is described with quark-diquark model and favored fragmentation functions，which is the analyzing power in the research of the transversity parton distribution function. With model calculations，theoretical predictions on the relation between Collins moment and Feynman variable，are given for charged pion production in semi-inclusive deep inelastic scattering of unpolarized charged lepton beams on transversely polarized hydrogen targets，in the kinematic range of the HERMES experiments.The kinematic range covered is 0.023

A Behavioral Simulation Method and an Optimized Design of Sigma-Delta ADC

ZHANG Xin,YU Dunshan,SHENG Shimin,TAN Zhichao

2009, 45(2):  209-214. 

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A behavioral simulation method is proposed for both system level and behavioral level design of Sigma-Delta ADCs (analog to digital converters).Compared with traditional behavioral simulation methods，the proposed method has a higher simulating speed and is more efficient in the behavioral design.With this simulation method，the imperfections of the analog cells as integrators，comparator，and the Op-Amps are analyzed in detail，which guides the design towards high performance. As a proof for the effectiveness of this method，a second-order Sigma-Delta modulator was designed and fabricated using a 0.13 μm mixed signal CMOS technology.The test results show that the modulator can achieve a peak SNR of 77.2 dB，which equals to a 12.5 bit resolution，and a power dissipation of 5.9 mW (6.2 mW with decimator) was occupied.

Maximum Power Analysis Based on Bayesian Inference and Vector Compression Techniques

CHEN Jie,LI Xianfeng,TONG Dong,WANG Keyi,CHENG Xu

2009, 45(2):  215-221. 

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To resolve oversize time consuming problem in simulation based maximum power analysis, Bayesian power model based on slice analysis is proposed. This model selects the input vector set which may generate maximum power and performs accurate power estimation for the compact sequence. The relationship between signal switch density and maximum power generation is analyzed, and then an input vector generation platform with switching density self-adaptation computing and Bayesian vector compression is proposed. The experimental results indicate that, Bayesian vector compression method results in 1005 times average estimation time speed-ups, and the average maximum-power error is 2.40%. When using vector generation method based on self-adaptation computation and Bayesian vector compression, the maximum power bottom limit can be increased with 1.99%, and average speed-ups reaches 163 times.

Three-Dimensional Steady / Pulsatile Flow Numerical Simulation of Blood Flow for Intracranial Lateral Aneurysm with a Straight / Slight Curved Parent Vessel

WEN Gongbi,CAI Qingdong,LIU Aihua,WU Zhongxue

2009, 45(2):  189-194. 

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Blood flow of lateral aneurysm modes with a straight/slight curved parent vessel was numerically simulated.The computations were carried out under incompressible，viscous，Newtonian flow，non-elasticity of the wall conditions by using an artificial compressibility algorithm to solve three-dimensional N-S equations.Flow pressure，wall shear stress，inflow volume and velocity/pressure field were calculated in the steady and pulsatile conditions.The maximum /minimum Reynolds number was set at about 475/152 based on diameter of parent vessel.The Womersley number was set to 2.5.These values are a representative of the middle cerebral arteries in vivo data. The significant results show that lateral saccular aneurysms subjected to wall shear stress concentration at proximal and the distal ends of cavity neck and more concentration for a straight parent vessel than slight curved vessel. It is observed that higher inflow rate from parent into cavity for slight curved than straight parent vessel in the most of time during a flow cycle. Two maximum pressure appear at proximal and aneurysm dome respectively, and rapid changes of blood flow direction and inflow quantity during a flow cycle result in rapid changes in inflow volume，wall shear stress and pressure at the proximal and distal wall of the cavity.The rapid changes would make continuous damage to the intima at the cavity neck and could lead to subsequent aneurysm growth or regrowth.

A Code Reservation and Spacial Reading Scheme for Active RFID

GUO Hongbo,ZHAO Yuping,NIU Jun

2009, 45(2):  199-203. 

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A cross layer design of quickly tag reading scheme is proposed，which consists of two steps.At the reservation step，a two-dimensional access which combines slotted-ALOHA and orthogonal code reservation is adopted，and tag direction is estimated by the reservation code and antenna array on the reader.At the tag data reading step，the different spatial characters of the tags are employed to cancel the multiple tag interference(MTI) in the same slot.Simulation results show that tag reading speed is very high and it increases with code length and antenna number.

A Resource Optimizing Algorithm in FPGA Based High Speed FIR Digital Filters

LI Ying,LU Weijun,YU Dunshan,ZHANG Xing

2009, 45(2):  222-226. 

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The authors analyze the detailed process of calculator schedule in high speed FIR (finite impose response) digital filter with add-and-shift algorithm based on FPGA (field programmable gate array). Different calculation situations and related schedule schemes are discussed and a clear rule of optimization is proposed. At last, an example of a 16-order FIR filter is implemented on Xilinx Spartan 3 3s1000ft256 FPGA platform. The occupied resource is 11.7% less than the one generated without optimization and/or 29.7% less than the one generated by Xinlinx Coregen^TM with distribute arithmetic (DA), respectively.

On-Line Topic Detection Using Named Entity Recognition

FU Yan,YANG Dongqing,TANG Shiwei,WU Wei,WANG Tengjiao,GAO Jun

2009, 45(2):  227-232. 

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In order to make on-line topic detection more efficient, a new method is proposed based on named entity recognition. New method extracts news elements from stories. Based on news elements, query composition is used to detect story link. This process reduces complex computation of text similarities. Experimental result indicates that the proposed method performs on-link topic detection accurately and efficiently.

High-Speed Parallel BCH Decoder Circuit in VLSI

JIN Jie,YU Dunshan

2009, 45(2):  233-237. 

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A high speed VLSI decoder architecture is proposed for a standard forward error correction(FEC) in optical network. In the proposed parallel decoder architecture, a novel parallel computation of syndrome is presented to reduce the hardware complexity. A method is introduced to derive an inversion-free algorithm from the decision tree algorithm with the number of correctable errors less than 5. Area and timing estimates obtained by logic synthesis with 0.18 CMOS technology show that the implementation of (4359,4320)BCH (Bose-Chaud huri-Hocquenheim) decoder can achieve 248 MB/s with an estimated area of 0.31 mm² including the embedded memory to store the received words. Compared with serial decoder, the proposed parallel architecture can achieve 8 times throughput with less than 2 times area.

Design and Implementation of SCL Layout Scaling

WU Di,MA Liang,LIU Xiaoyan

2009, 45(2):  238-242. 

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A new set of scaling layout flow is presented to reuse IP hard core. The ratio design algorithm is developed to design scaled layout considering the relation of two different technology. Based on the ratio design algorithm, programmed data processing, the layout can be scaled appropriately and reused on the new technology nodes. Experiment proved the effectiveness of this method in use of SCL design and improvement of design efficiency.

Ear Recognition Based on Wavelet Transform and Block DCT

ZHAO Hailong,MU Zhichun,DING Wenkui,ZHANG Xia

2009, 45(2):  243-247. 

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A new dimension reduction method was proposed based on two-dimension discrete wavelet decomposition and block discrete cosine transform. The new method was compared with the famous PCA-LDA method which was widely used for feature extraction and dimension reduction in pattern recognition. The experimental results show that the new method could get approximately equal retrieval accuracy to PCA-LDA method, but it performed better in calculation complexity and speed than the latter. So the proposed method is an effective dimension reduction means for ear recognition.

Analysis to Methods of Double-Theodolite Anemometry

ZHANG Yuntao,JIANG Haoyu,LIU Shuhua

2009, 45(2):  248-256. 

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Based on the characteristics of atmospheric field observation, the influence of man-made operating error and instrument error is compared, and conclusion is drawn that operating error predominates in this process. Then frequently-used and available methods for processing data of double-theodolite anemometry are presented, and their applicability is analyzed. However, none of those methods can be suitable for use unconditionally while limited maximum error is given. Consequently, a joint method based on the advantages of all available methods is introduced, which can be applied to most comprehensive and extensive conditions. Finally, compared with base-line anemometry by using the observation data from Duhu at 10:00 on 16 August, 2007, and the advantage of the joint method is displayed.

A Study of Cloud Classification in the Northwestern Pacific by Using FY-2C Data

YIN Yue,LI Wanbiao,YAO Zhanyu,KIM Won-guk

2009, 45(2):  257-263. 

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The tests of navigation are carried out using 31 FY-2C images in Aug. 2006, The result shows that the navigation error is less than 0.13 scan line, which is good enough for cloud classification analysis. Two methods of cloud classification (nephanalysis and cluster analysis) are presented and the classifying distributions are compared with the FY-2C NOM cloud product. Cloud categories obtained in nephanalysis are more than FY-2C NOM cloud product, and middle/low clouds are recognized well by nephanalysis. The results by cluster analysis are better than NOM cloud product, and cloud distribution are more realistic.