最新刊期
卷 17 ， 期 4 ， 2013
- 摘要：Forest vertical structure is the most complex of all vegetation parameters which describes the vertical distributing characteristic of vegetation community. The forest vertical structure not only affects the contribution of vegetation components for canopy reflectance,but also constrains the extraction accuracy of forest characteristic parameters. It also has significance influences on land surface process. With the development of remote sensing technology,forestry remote sensing developed from early forest classification mapping to quantitative retrieval of forest characteristics parameters. At present,the forest parameters that retrieved from remote sensing data include leaf area index,forest biomass,concentrations of chlorophyll and carbon storage. These parameters mainly describe the forest biochemical characteristics and horizontal structures. There are few researches on the forest vertical parameters inversion. This paper firstly focuses on two parameters of Leaf Area Density （ LAD） at different heights and vertical Canopy Height Profiles （ CHP） which describes the forest vertical structure in remote sensing,and summarizes their extracting methods based on remote sensing technology. Secondly several vertical profiles of typical vegetation types are collected. Finally,issues in the forest vertical structure parameter extraction are discussed,and the new research directions in this area are suggested.关键词：forest vertical structure;leaf area density;canopy height profile;InSAR;lidar
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发布时间：2021-06-10 - 摘要：High Accuracy Surface Modeling （ HASM） method,based on the fundamental theorem of surfaces,provides a solution to the error problem that long troubled geographic information science. Although HASM has a sound theoretical foundation,the low computing efficiency arising from solving large scale linear systems,poses a severe limitation on its wide-spread applications in construction of large scale and high resolution surfaces. In order to achieve a high speed,we developed an algorithm based on two dimensional Double Successive Projection Method （ HASM-DSPM） ,which significantly improves the performance by adopting strategies of project space adjustment and two-step correction. HASM-DSPM is examined by both numerical experiment and real world experiment,the results of which both illustrate that HASM can surpass Gauss-Seidel （ GS ） and Modified GS （ MGS ） in convergence pace and computational speed. Furthermore,compared with other classical surface modeling methods,our method has obviously higher accuracy.关键词：HASM;two-dimensional double successive projection;surface simulation;MGS iteration;DEM
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发布时间：2021-06-10 - 摘要：In this paper,we uses Digital Elevation Model（ DEM） with three different scales in 78 study areas to calculate multiscale relief,and tries to ascertain the evaluation model of relief and to calculate the optimum statistical unit. The experiment result shows that the relief of the same experimental area with different scale exists a certain extent of difference,the smaller difference of the scale,the smaller difference of the relief. There is a strong relationship between the relief and the terrain factors of the experimental area such as the average elevation,the elevation difference,the average slope and the average slope variability. Based on this,we build the prediction model of the relief. We use the prediction model to estimate the scale of optimum statistical unit and the accuracy of the prediction model to fitted parameter is above 95% . The experimental results show that the model can effectively determine the optimum statistical unit of relief.关键词：topographic relief;optimum statistical unit;neighborhood analysis;terrain factor;elevation difference;average slope
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发布时间：2021-06-10 - 摘要：The active contour extraction algorithm,which uses the Gradient Vector Flow （ GVF） field as its external force,is called a GVF snake. This paper first introduces the principle of the GVF snake. Then,the role of the GVF snake’s internal and external forces,and the impact of the initial boundary on the result is investigated. After that,a reasonable solution is proposed for the GVF snake initialization and weighting parameter determination. Finally,an interactive GVF snake algorithm is designed and applied to extract irregular water boundaries from remotely-sensed images. In this algorithm,the initial boundary is acquired using the region growing algorithm based on seed pixels,and the weighting parameters are determined interactively. The real boundary is obtained using the GVF snake algorithm. The experiments show that the interactive GVF snake algorithm can extract the water boundary easily,fast and accurately,even if it is very irregular.关键词：GVF snake algorithm;internal force;external force;weighting parameter;irregular water boundary;initial boundary;boundary extraction
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发布时间：2021-06-10 - 摘要：Gravity terrain correction is a critical step in regional gravity survey. The main challenge for gravity terrain correction is how to rapidly and inexpensively reconstruct high-quality terrain near the gravity survey station. This paper proposes a fast near-region terrain correction approach based on panoramic stereo vision and photogrammetry techniques. A fast and low-cost topographic mapping system is designed and developed for this purpose. To miniaturize the system and assure required mapping accuracy,we theoretically analyze and optimize the hardware design. The developed software system generates DEM automatically from panoramic stereo images and calculates the gravity correction value at each station. The system has been verified in several filed tests with various terrain circumstances. The test results demonstrate that the developed gravity terrain correction method s ignificantly outperforms the traditional field surveying methods in efficiency and accuracy.关键词：gravity terrain correction;topographic mapping;panoramic vision;stereo image matching;point cloud filtering
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发布时间：2021-06-10 - 摘要：A Medium-Resolution Imaging Spectrometer （ MERIS） sensor,with reasonable ocean color bands and a high spatial resolution of 300 m,has considerable potential with respect to the monitoring of inland waters. In the quantitative retrieval of water environmental parameters by using a remote sensing image,accurate atmospheric correction is very significant. In the present study, oxygen and water vapor absorption bands are used for improving the traditional black pixel assumption based on the near-infrared bands. The method of calculating aerosol parameters through MERIS Level 2p data is developed; this method is assessed using MERIS Level 1p data recorded on Nov. 11,2007; Nov. 20,2008; and April 25,2009. Meanwhile,the in situ measured data are used for a comparison with the modeled values. The obtained results show that the proposed method is efficacious with RMSP of less than 25% . Another important work is also carried out,that is,a comparison of the proposed method with other algorithms such as a case Ⅱ atmospheric correction algorithm embedded in a MERIS （ Beam） processor,aerosol-thickness-aided 6S,and modified black pixel algorithm. The results indicate that the proposed algorithm has certain applicability considering,because it is independent of the synchronous measured aerosol data.关键词：atmospheric correction;MERIS data;case Ⅱ water;absorption bands
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发布时间：2021-06-10 - 摘要：Address matching algorithm that has broad application prospects is the core and key technology for location-based services. This paper analyzes the existing three major address matching algorithms which are the level based matching algorithm,the full-text search algorithm and the regular expression algorithm. An address matching algorithm based on Chinese natural language understanding is proposed in this paper. The complete process of this new algorithm includes five parts as pretreatment,address parsing,address elements standardization,reasoning about address matching and matching registration. This paper focuses on address parsing and reasoning matching the two most important parts. The paper establishes a complete Chinese address matching algorithm based on natural language understanding. In the principle of Chinese segmentation and semantic reasoning in natural language understanding,the new algorithm achieves the goal to combine natural language understanding with address matching by processing Chinese address of unstructured format. To check the new algorithm,an address matching experimental system was developed. The matching experiment using 1000 resident addresses of Puyang city,Henan province shows that the matching rate can be 95% or more and the accuracy rate is above 93% .关键词：natural language understanding;address matching;address element;address parsing;Hidden Markov Model
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发布时间：2021-06-10 - 摘要：In a large three-dimensional Geographic Information System （GIS） ,we usually reconstruct a triangular network on the local terrain on the basis of the complete preloaded terrain data for some specific applications such as a physical engine. In order to handle this problem,we propose a real-time algorithm for local three-dimensional terrain simplification,by using up and down sampling and the pyramid theory. This algorithm executes the down sampling and the up sampling at the triangle grid of the original terrain,then performs the partial revision with the predicted residuals in specific regions,and finally obtains the fine terrain triangular network,which is considerably similar to the original terrain. We have applied this algorithm to the simulation of a vehicle driving application in our GeoBeans three dimensional system. The terrain constructed by this algorithm is simplified and stable. It will be updated according to the range of the vehicle and be destroyed or reconstructed as needed. Our test shows that if the threshold of the predicted residuals is 0. 1,the number of triangles will reduce to 2/3 of the original number; if the threshold is 0.2,the number of triangles can almost reduce to 1/4. Hence,as demonstrated here,in the visual precision permitted range,this algorithm results in a good terrain simplification with little time consumption,and it satisfies the request of real-time simplification for a three-dimensional system and the simulation of a vehicle driving application.关键词：triangular network terrain;local real-time;image pyramid;up and down sampling;physical engine
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发布时间：2021-06-10 - 摘要：The SEaTH method （ SEparability and THresholds） can select features and compute thresholds automatically based on Jeffries-Matusita distance to separate classes,which may cause information redundancy and affect classification results. In this paper,a new method based on SEaTH is proposed,and then the method that considers the Jeffries-Matusita distance,the inner class distance,and the correlation of different features is used in the classification of multi-resolution remote sensing images of Zhaoqing, China. The result indicates that our method can select more effective information than the original SEaTH algorithm,with accuracy in extracting farmland improved by 12. 26% ,and total accuracy improved from 80% to 85. 26% . Such an improvement is significant to the classification when multi-temporal data are difficult to be obtained.关键词：object-oriented classification;feature selection;SEaTH algorithm;land cover classification;feature decorrelation
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发布时间：2021-06-10 - 摘要：This paper presents an algorithm for the retrieval of daytime land surface temperature （ LST） from the Terra/MODIS data,which considers the atmospheric radiation effects due to the viewing zenith angle （ VZA） variation. The MODTRAN4 model,875 profiles of TIGR3 database and 106 surface emissivity spectra of the ASTER spectral library were used to obtain the Split-Window Algorithm （ SWA） coefficients. The Root Mean Square Errors （ RMSEs） of LST retrieval using the MODTRAN4 simulation are 0. 34 K. Sensitivity analysis confirmed that the algorithm is not sensitive to total column water vapor content （ TCWVC） for the moderately moist atmospheric conditions. In addition,LST retrieval error due to the VZA effect was reduced. Retrieved LSTs have compared with Mao,et al. ’s LST and MOD11L2 LST. Surface Radiation （ SURFRAD） budget network measurements have been used for LST validation over six sites during the entire month of June 2009. The RMSE values of LST were 0. 93 K,1. 49K and 1.0K for this new algorithm,Mao,et al. ’s algorithm and MOD11L2 LST,while the average biases were-0. 66K,1. 34K and -0.38 K,respectively.关键词：land surface temperature;split-window algorithm;MODIS;SURFRAD
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发布时间：2021-06-10 - 摘要：We propose a novel multi-look synthetic aperture radar image segmentation method that combines Voronoi tessellation, expectation maximization （ EM） ,and maximization of the posterior marginal （ MPM） technology. The image domain is partitioned into a group of sub-regions by Voronoi tessellation,each of which is a component of homogeneous regions. Then a multi-look SAR image is modeled on the supposition that the intensities of pixels in each homogenous region satisfy an identical and independent gamma distribution. The image segmentation model is constructed based on the Bayesian paradigm. Finally,the EM/MPM algorithm,which integrates the EM algorithm for model parameter estimation and the MPM algorithm for image segmentation,is implemented. The proposed method expands pixel-based MRF to region-based MRF and achieves optimal segmentation and parameter estimation simultaneously. Results obtained from both real RADARSET-Ⅰ/Ⅱ and simulated SAR intensity images indicate that the proposed method is efficient and promising.关键词：Voronoi tessellation;EM /MPM;SAR;image segmentation
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发布时间：2021-06-10 - 摘要：Weed identification is a basic task in precision agriculture,as well as in the principle of variable spraying and accurate weeding. Field imaging spectrometer data,with both hyperspectral and high spatial resolutions,have potential applications in weed identification. Currently,methods for weed identification include considering shape features based on machine vision,which perform poorly when weeds and crops have similar shape features,while the use of hyperspectral features have low efficiency when it is identified in pixels. To overcome the limitations of these existing methods,a new weed identification method combining the strengths of both object-oriented and spectral feature matching approaches is proposed. The proposed method extracts and analyzes the shape features and the spectral curves of plant object samples,and builds a decision tree using shape feature rules and spectral angle mapper to identify the plant objects in the experimental field. The results show that the proposed method could identify different kinds of plant objects with similar shape features by using hyperspectral features,and could overcome the difficulties in identifying same objects with different spectra and different objects with the same spectrum by using shape feature rules. The identification accuracy of the described method is higher than both the spectral angle mapper method and the color and shape analysis.关键词：field imaging spectrometer data;weed identification;object-oriented;shape feature;spectral angle mapper
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发布时间：2021-06-10 - 摘要：Traditional Cellular Automata （ CA） requires parameter adjustments and results modification to improve performance especially in a long simulation period. This paper introduces the ensemble Kalman filter （ EnKF） into the CA model and proposes a new geographical cellular automata model based on joint state matrix. The model will adjust model parameters and correct simulated results dynamically in the process of simulation by assimilating remote sensing observations. The change of model parameters can properly reflect temporal and spatial variations in the transition rules. Besides,the model can effectively release accumulated model errors. It was applied to the urban expansion simulation of Dongguan,Guangdong province,China. Experiments indicate that this model can modify the parameter value which can properly reveal the urban development pattern. It also can produce more reasonable results than logistics CA model and EnKF CA model in simulating this complex region.关键词：cellular automata;urban expansion;data assimilation;ensemble kalman filter;joint state matrix
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发布时间：2021-06-10 - 摘要：This paper investigates the characteristics of high resolution full-polarization Synthetic Aperture Rader （ SAR） data combined with the selected texture characteristic,and uses the theory of the agglomerative hierarchical clustering algorithm to present a sea ice segmentation method using full-polarimetric SAR data. By comparing the result of this method with the results of the K-Means,ISODATA,and fuzzy c-means methods,we verified that our method can reduce the number of small patches and realize good segmentation accuracy. The results verify the validity of this method.关键词：sea ice types;polarization SAR;texture feature;agglomerative hierarchical clustering segmentation algorithm;sea ice in Liaodong Bay
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发布时间：2021-06-10 - 摘要：This research explored the potential of the use of the CCD image of the HJ satellite to derive Suspended Sediment Concentrations （ SSC） of dynamic water bodies at Hangzhou Bay,which is a typical turbid water body in China. Through the analysis on the correlation between Remote Sensing Reflectance （ Rrs ） and SSC,two apparent reflectance peaks at approximately 690 and 830 nm have been found in the third and fourth bands,respectively. The result also shows that a good correlation exists between R rs and SSC when the wavelength is more than 700 nm. Based on the measured correlation between SSC and Rrs ,the retrieval model is established using the ratio of band 4 and band 3 as remote sensing factor,and the model determination coefficient of 0. 90 is reached. Through the Moderate Resolution Imaging Spectroradiometer （ MODIS）-derived Aerosol Optical Depth （ AOD） data,which are calculated from the Near Infrared-Short Wave Infrared （ NIR-SWIR） atmospheric correction,the atmospheric correction of HJ CCD imagery is realized. The correction-relative errors of the third and fourth bands are 5. 54% and 6. 97% ,respectively. The result demonstrates that the relative error of SSC derived from HJ CCD imagery is 7. 12% ,and SSC at Hangzhou Bay,which also has significant internal diversity,is much higher than that in the entrance of the Yangtze River. This research demonstrated that HJ CCD imagery can be used to evaluate SSC at Hangzhou Bay,if the appropriate atmospheric correction method and retrieval a lgorithm are used.关键词：HJ CCD;Hangzhou Bay;SSC;remote sensing reflectance;atmospheric correction
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发布时间：2021-06-10 - 摘要：Focusing on the serious haze event in January 2013 in Beijing,we analyzed remote sensing results of haze aerosol properties based on passive-active joint monitoring approaches. The analyses show that the active remote sensing approaches have advantages during the high pollution cases or the nighttime,while the passive approaches provide more information for aerosol characterization. By joint use of ground-based site,vertical profile,and satellite coverage monitoring,one can preliminarily realize the stereoscopic observation of haze aerosols.关键词：haze;aerosol;remote sensing;ground-based LiDAR;active and passive remote sensing monitoring
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发布时间：2021-06-10 - 摘要：The correlation between fine Particulate Matters （ PM2.5 ） and Fine-mode Aerosol Optical Depth （ AODf ） is established. AODf is obtained from product of Aerosol Optical Depth （ AOD） and fine-mode fraction at Beijing site belonging to the AErosol RO-botic NETwork （ AERONET） in January 2013. And then we compare estimation with observation of PM2.5 from 1 to 15 February, 2013. The results show that the developed correction method is effective to estimate PM2.5 during haze,with root-mean-square error of 50 μg / m3 at a mean level of 85 μg/m3 . The relationship between AODf and PM2.5 is obviously better than that of AOD and PM2.5 . It is also found that when the relative humidity is higher than 80% ,the humidity correction on AOD-PM2.5 correlation is limited,and the vertical correction cannot improve the correlation during haze.关键词：aerosol optical depth;PM2.5;fine mode fraction
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发布时间：2021-06-10 - 摘要：According to the aerosol optical properties,the aerosol chemical composition can be simplified as a mixture of five components. They are three absorbing components like Black Carbon （ BC） ,Brown Carbon （ BrC） ,and dust （ DU） ; one scattering （ non-absorbing） component of ammonium sulfate （ AS） as well as aerosol water （ AW） ,which is responsible for aerosol hygroscopic characteristics. In this study,we estimate the contents of the five chemical components of haze aerosols during January 2013 over Beijing from the ground-based remote sensing measurements. We find that BC,BrC,DU,AS and AW occupy 2% ,9% ,30% , 33% ,and 26% in volume,respectively on average for the selected haze days,while they are 3% ,3% ,15% ,71% ,and 8% on a verage for the selected clear days. As for the column mass concentration,BC,BrC,DU,AS and AW in the haze aerosol are 7, 35,166,131,and 73 mg/m2 on average,while during the clear days they are 4,4,29,78 and 6 mg/m2 on average. The comparisons of these remote sensing results with in situ BC and PM 2. 5 measurements are also presented in the paper. Results show that the retrievals agree well with the measurements,with coefficient R2 0.45 for BC and 0. 85 for PM2.5 .关键词：haze;aerosol components;sun-sky radiometer;dust;BC
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发布时间：2021-06-10 - 摘要：Haze pollution becomes more and more frequent in urban regions of China. Compared to ground based measurement approaches,satellite remote sensing can obtain observation of haze in wide areas and monitor their distribution and intensity. The Chinese environmental satellites of HJ-1A and HJ-1B play important roles in atmosphere monitoring due to their high spatial resolution, high temporal resolution and wide swath. In this paper,aerosol optical depth during haze in January 2013 is retrieved u sing HJ-1 CCD blue and green bands based on the assumption of stable surface reflectance in a short period. Applications of HJ-1 CCD haze monitoring are also evaluated and feasibility and advantages of the high-resolution satellite are analyzed.关键词：high spatial resolution;aerosol optical depth;Beijing;haze;HJ-1 CCD
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发布时间：2021-06-10 - 摘要：Aerosol optical and microphysical parameters retrieved from ground-based sun-sky photometer （ CE318） measurements are used to investigate aerosol properties during heavy haze days. The heavy haze episode in January 2013 is analyzed,and we find that: （ 1） Aerosol Optical Depth （ AOD） in haze days （ an average of 0. 87 at 440 nm） ,is much higher than that of clean days, and can reach up to about 3 in some seriously polluted conditions. （ 2） Aerosol properties are well related to the haze pollution levels. For example,the averaged ngstrm exponent,imaginary part of refractive index,single scattering albedo and asymmetry factor under clean condition are 1. 3,0. 04,0. 73 and 0. 58,respectively,while the corresponding values in polluted days change to 0. 95,0 . 01,0. 92 and 0. 67,respectively. （ 3） The volume proportion of fine mode aerosol is higher than that of coarse mode during the haze episode. The average volume ratio of fine mode to total aerosol is 73% ,with the maximum of 90. 5% . The fine mode radius peak increases with the increase of AOD,indicating clearly hygroscopic growth effects,while that of coarse mode aerosol decreases accordingly. Moreover,the peak radius of size distribution is 0. 43 μm when the heaviest haze pollution during January 2013 occurs.
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发布时间：2021-06-10 - 摘要：In order to investigate characteristics of atmospheric boundary layer height （ ABLH） during haze pollution,we used ground-based CE370-C micro pulse LiDAR to derive the ABLH during January 2013 over Beijing,based on the gradient method. We find that the ABLH in severe haze days is lower than that in weak haze days and beneath about 500 m,with daily averaged value of about 424m. The ABLH has negative correlation with the concentration of surface PM2. 5 . The comparison of LiDAR observation with radiosonde detection is also presented in the paper and results show that two approaches have good consistency with difference less than about 86 meters.关键词：haze;atmospheric boundary layer height;lidar;gradient method
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发布时间：2021-06-10 - 摘要：we estimated anthropogenic contributions to Aerosol Optical Depth （ AOD） during days of high haze level using ground-based measurements in Beijing （ January 2009 and 2013） . We compared the anthropogenic AOD （ AODan ） with optical parameters determined directly from aerosol samples. The results showed: （ 1） The monthly mean AODan （ at 440 nm） of January was 0.88 in 2009 and 0. 44 in 2013; （ 2） The proportion of days where contributions from AODan dominated in January 2013 was 86. 7% ,higher than that in January 2009 （ 62. 5% ） ; （ 3） The ratio of the AODan to total AOD （ at 440 nm） was about 88% in January 2013, indicating the importance of the anthropogenic aerosol contribution to haze pollution; （ 4） The two haze events studied featured contributions from accumulation of local pollutants and pollutants transported from surrounding areas of Beijing.关键词：anthropogenic aerosol optical depth;haze;aerosol accumulation mode fraction;aerosol from ground-based observation
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发布时间：2021-06-10 - 摘要：The vertical distributions of aerosols are obtained based on the micro-pulse LiDAR. We analyzed coefficients at different altitudes in January and February 2013. The results show that aerosol vertical distributions of clear days are non-homogeneous with multiple layers at different altitudes,while aerosols are concentrated in the layer below than about 1 km during severe haze days. Analyses show that aerosol extinction coefficients are larger in heavy haze days,reaching up to five times of that of medium polluted days and 50 times of that of clear days. It is also found that Aerosol Optical Depth（ AOD） is in good relation to aerosol e xtinction coefficients at 400 m during this haze event.关键词：lidar;sun-sky radiometer;aerosol extinction coefficient;haze
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发布时间：2021-06-10 - 摘要：We analyzed aerosol optical,physical properties in Beijing city in January of 2013 based on ground-based remote sensing data,and used radiative transfer model to estimate aerosol radiative forcing. The results show that water-soluble Aerosol Optical Depth （ AOD） increases rapidly in haze days,and contributes most to the total AOD （ > 70% ） ,black carbon aerosol AOD increases also in haze days,which is about eight times larger than clear days. The direct radiative forcing caused by aerosol is significant,but different aerosol compositions have different effects. Black carbon dominatesforcing in the atmosphere （ > 57% ） , while water-soluble dominates in surface forcing（ > 60% ） .关键词：anthropogenic aerosol;haze;radiative effects;ground-based remote sensing
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发布时间：2021-06-10 - 摘要：<正>《遥感学报》创刊于1997年,是随着中国遥感事业的发展而成长起来的综合性学术期刊。创刊以来,《遥感学报》结合中国遥感事业不同时期的重点和需要,刊登了大量国内最新科研成果和国家重点支持的研究项目的成果论文,对中国遥感科学技术的发展和人才培养发挥了巨大作用。学报致力于报道遥感领域及其相关学科具有国际、国内先进水平的研究报告、阶段
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发布时间：2021-06-10
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