最新刊期
卷 13 ， 期 5 ， 2009
- 摘要：Upward scattering coefficients and diffuse absorption for the down-and up-welling streams are key factors for remote sensing of waters,and the interaction between biology and optics.They are also important parameters of underwater light fields.On the assumption that the radiance field has no internal light source,no inelastic scattering and the water surface was flat,we studied the effects of the zenith of incident,albedo and scattering coefficient on upward scattering coefficient,diffuse absorption coefficient for the downwelling and upwelling streams on condition that a scattering phase function was selected.The upward scattering coefficient showed an increase with the zenith of incident increasing,but the coefficient did not change along with the albedo and scattering coefficient just below water surface.With depth increasing,the profile of upward scattering coefficients gradually approached a constant,and the constant increased with albedo increasing.The profile of upward scattering coefficients strictly increased and then gradually approached a constant with depth increasing when the incidence was normal to the water surface.With further enhancement of zenith angle,the profile gradually increased,then decreased,hereafter kept invariable;while the invariant value increased with albedo increasing,but did not change with zenith angle of incident.The pro-files of diffuse absorption coefficients for downwelling streams gradually shifted from strictly increase and followed stability to the new trend which took on first increase and next decrease,then to a constant state.Given that scattering coefficient and albedo was the same,the diffuse absorption coefficients for downwelling streams of different incident zenith converged to stability gradually.The less the albedo was,the more rapid convergent rate was,the shallower the depth of approaching to asymptotic state was.The characteristics of diffuse absorption coefficient for upwelling streams were very similar to that of diffuse absorption coefficient for downwelling streams,the former was merely bigger than the latter,and the diffuse absorption coefficients for upwelling streams were the maximum among them.关键词：upward scattering coefficient;diffuse absorption for the downwelling streams;diffuse absorption for the up-welling streams;multiple scattering
- 124
- |
- 367
- |
- 2
发布时间：2021-06-10 - 摘要：Photosynthetically Active Radiation（PAR） is an important parameter in models of ecosystem dynamics and carbon cycle.A method is presented with which instantaneous PAR can be calculated with high accuracy from Moderate Resolution Imaging Spectroradiometer（MODIS） products and Digital Elevation Model（DEM）.The method is based on a simplification of the general radiative transfer equations,which considers five major processes of attenuation of solar radiation:Rayleigh scattering,absorption by ozone and water vapor,aerosol scattering,multiply reflectance between land surface and atmosphere,and three terrain factors:slope and aspect,isotropic sky view factor and additional radiation by neighbor reflectance.Comparing the modeling PAR with observational PAR in Yucheng site and Changbai Mountain site in 2006,the correlation coefficient are 0.929 and 0.904 respectively,and the average errors are 10% and 15% respectively,which should be sufficiently accurate for reflecting the change of PAR.Comparing modeling PAR with the consideration of complex terrain with modeling PAR without the consideration of terrain,this paper quantificationally analyzes the effect of complex terrain.关键词：photosynthetically active radiation（PAR）;MODIS products;complex terrain
- 188
- |
- 506
- |
- 3
发布时间：2021-06-10 - 摘要：This paper addresses the intercalibration of the two split-window channels IR1（10.9μm） and IR2（11.9μm） of SVISSR（Stretched Visible and Infrared Spin Scan Radiometer） onboard the geostationary satellite FY-2C（FengYun 2C） against the most accurate and stable AIRS（Atmospheric Infrared Sounder） sensor onboard the polarorbit satellite Aqua.The intercalibration was implemented using both the AIRS and SVISSR data around the equator in December of 2006 and 2007.The results reveal that:（1） the SVISSR data are highly linearly correlated with the convolved AIRS data,（2） calibration errors exist in SVISSR channels IR1 and IR2,and（3） the discrepancies become larger with time increment.With respect to the AIRS/Aqua measurements,when the brightness temperatures in SVISSR channels change from 220K to 340K,the temperature adjustment for IR1 in Dec.,2006 varies from 5.8K to -4.4K,and changes from 6.9K to -5.1K in Dec.,2007;The temperature adjustment for IR2 in Dec.,2006 goes from 2.2K to -1.5K,and varies from 6.3K to -6.1K in Dec.,2007.关键词：intercalibration;SVISSR/FY-2C;AIRS/Aqua;split-window channels
- 177
- |
- 253
- |
- 2
发布时间：2021-06-10 - 摘要：The Bidirectional Reflectance Distribution Function（BRDF） of land surfaces specifies the behavior of surface directional reflectance as a function of illumination and viewing angles.The bidirectional reflectance products of the Moderate resolution Imaging Spectroradiometer（MODIS） and the Multiangle Imaging Spectroradiometer（MISR） and their BRDF model parameters products have been available respectively.Since the BRDF model parameters are inverted from limited angular observations for a given pixel,it is necessary to evaluate whether they can effectively characterize the directional reflectance in other viewing directions.In this study,we choose four kinds of land cover types to analyze the representation of MISR and MODIS BRDF model parameters,by comparing the directional reflectance extrapolated using the BRDF model parameters with the observed directional reflectance.The results show that:（1） both MODIS and MISR BRDF model parameters have better representation on directional reflectance at some viewing directions.Especially MISR BRDF model parameters have preferable representations at MODIS viewing directions;（2） the representative ability of both BRDF model parameters tends to weaken when the viewing zenith angle increases;（3） from the analysis of the observed data set shown in this paper,it seems that the representative ability of MODIS BRDF models is better near cross-principal plane than that near principal plane.关键词：BRDF model;MISR;MODIS;model parameters;extrapolation
- 142
- |
- 703
- |
- 8
发布时间：2021-06-10 - 摘要：The remote sensing images captured at different time may be quite different in color,brightness because of various atmospheric conditions,seasonal changes in vegetation characteristics and other reasons.These differences not only cause great impact on subsequent image classification and change detection,but also bring difficulties in remote sensing image mosaicking.This paper presents a color calibration method based on remote sensing automatically classification and lαβ color space transformation.Multi-images mosaic with ETM captured at different time are experimented by applying this method.The results of experiments show that color calibration method can calibrate difference of color and brightness in images caused by the different time more effectively than conventional methods,such as overlapping zone calibration and histogram matching.So it can improve the accuracy of follow-up image classification and change detection,as well as the remote sensing images mosaicking effect.关键词：remote sensing;color calibration;mosaicking;color space transformation
- 136
- |
- 434
- |
- 1
发布时间：2021-06-10 - 摘要：LIDAR data is accurate 3D data of terrain acquired from airborne laser detection and ranging system.Compared with hardware technique,data post-processing technique of LIDAR data is weak and time consumed.In this situation,a HMCFA（Hierarchical Moving Curved Fitting Algorithm） filtering method of LIDAR data is reported in this paper.Firstly,block grid searching and indexing mechanism is set up to label discrete LIDAR cloud points.Secondly,quadratic polynomial is set up to fit land terrain with different window size.At last,adaptive threshold is used to distinguish ground points and non-ground points.Accuracy assessment results indicate that the filter error is less than 1m,which can be used in application.关键词：Light Detection and Ranging（LIDAR）;Hierarchical Moving Curved Fitting Algorithm（HMCFA）;filtering;quadratic polynomial;adaptive threshold
- 191
- |
- 1061
- |
- 10
发布时间：2021-06-10 - 摘要：This paper developes a method to retrieve the typhoon intensity and location of the typhoon center from QuikSCAT.The typhoon intensity is derived by searching the maximum of the wind speed where the typhoon is present.The method to derive the location of typhoon center is based on the knowledge of typical wind field structure of mature typhoon,by searching the center of the helix structure of wind direction,local minimum of the wind speed around the typhoon eye,or the local minimum of the back scattering coefficient.To improve the accuracy of wind vector retrieval in typhoons,the Holland’s typhoon model is employed in the process of ambiguity removal to correct the wind direction error caused by the failure of Circular Median Filter（CMF） around the eye wall,while the Geophysical Model Function（GMF） NN-T-GMF is used as a replacement of the QSCAT-1 to reduce the bias induced by the inaccurate of the existing business operational GMF at high winds.Based on this method,the track and changes of typhoon intensity for typhoon Ioke and Kaemi are extracted from continuous QuikSCAT data.The results are comparable with the best-track analysis result form National Hurricane Center,indicating that QuikSCAT can be a powerful instrument to monitor and track typhoons.关键词：QuikSCAT;Retrieve;typhoon tracking;typhoon observation
- 159
- |
- 590
- |
- 4
发布时间：2021-06-10 - 摘要：MODIS aerosol product Collection 005（C005） is an upgrade of C004,and is introduced in detail in this paper.Through fitting with AERONET ground observation aerosol optical thickness（AOT）,MODIS aerosol C004 and C005 products of TERRA and AQUA are compared and evaluated to analyze their applicability in the north of China at Beijing and Yulin sites.We match AERONET ground-based data with MODIS aerosol product by band interpolation and temporal-spatial matching,then compare and evaluate them by linear fitting.We conceive a scale of temporal-spatial matching in the north of China considering the local aerosol movement velocity of given sites.The results show that:（1） C005 product algorithm does not improve the accuracy of AOT at Beijing site,and the accuracy drops when AOT< 0.8;both C004 and C005 products do not have a significant application at Beijing site,but the C004 performs better than C005 products.（2） At Yulin site,TERRA-MODIS C004 product meets the demand,and the accuracy of AQUA-MODIS C004 product decreases.Compared with the C004 product,the accuracy of the C005 product improves greatly,and correlation coefficients between AOTs of three bands（470nm,550nm,660nm） and the AERONET ground observation data are all higher than 0.9.It could be concluded that the method of the surface reflectance determination used in the new algorithm is feasible for dark dense vegetation,but is not suitable for the bright surface.关键词：MODIS;C005;AERONET;aerosol optical thickness（AOT）;validation
- 163
- |
- 1315
- |
- 11
发布时间：2021-06-10 - 摘要：In China,hemorrhagic fever with renal syndrome（HFRS） is still endemic in 31 of 32 provinces,autonomous regions and metropolis,and accounts for 90% of the HFRS cases reported globally.Some studies indicated that HFRS incidence was significantly different among different precipitation,temperature level,land-cover,soil types and normalized difference vegetation index（NDVI）.The current study proposed to explore the temporal relationship between the inter-annual variation in the number of cases of human disease caused by hantavirus and time series of NDVI in order to predicate the trend and level of the case number of HFRS.Dayangshu district in Inner Mongolia Autonomous Region was selected as the study area.Based on Landsat TM image,the land-use of this district was divided into four categories:hill,forest,farm-land and residence area.The relationship between the case number of HFRS and time series NDVI was explored by using graphic demonstration,correlation test and linear regression analyses.The study indicated that the highest correlation coefficient was 0.67（P value<0.001） between three months backward NDVI and the number of cases of HFRS in farmland.The result also indicated that the peak of cases happened 3 months later than the peak of monthly NDVI.This study quantified the temporal relationship between NDVI and the number of the cases of HFRS.关键词：remote sensing;HFRS;SPOT;NDVI
- 169
- |
- 346
- |
- 1
发布时间：2021-06-10 - 摘要：The Microwave Temperature Sounder,the Microwave Humidity Sounder and the Microwave Radiation Imager were flown on the new-generation polar satellite FY-3A in China.The microwave sensors’ calibration after launch is a critical problem.Using the SSM/I data,and the surface and raob observations,the stability of microwave emissivity in Simao Yunnan is analyzed based on the microwave modeling in this article.The results show that its vegetation situation is very good,and the surface microwave emissivity is stable.The surface microwave emissivity has weak season-to-season variation in law of sines（the changing range is less than 0.02）.It also has very small year-to-year difference,which can be corrected by modeling based on the surface and raob observations.关键词：Simao Yunnan;microwave emissivity;stability analysis;SSM/I
- 142
- |
- 217
- |
- 4
发布时间：2021-06-10 - 摘要：At present,the formation,evolution and simulation of spatial structure of village and small town are becoming the focus in the fields of geography,planning,remote sensing science,geographic information science and other related disciplines,which also receives the close attention of the management.In this study,we take Xianghe County of plain,Miyun County of mountainous area and Kunshan City of aqueous area for examples where characteristic analysis of village and small town spatial structure is carried out.The location and spatial scope models of village and small town based on grid are established,which is carried out with the help of GIS spatial analysis and modeling technology.In addition,according to Tyson polygon model,a new idea is brought forward that the spatial range of village and small town is determined by land-benefit instead of distance.The two models can provide reference for location and scope determination of village and small town because the factors are more comprehensive and more specified.This research can provide help for the planning of village and small town.关键词：village and small town;spatial structure;characteristic analysis;GIS;grid
- 170
- |
- 909
- |
- 1
发布时间：2021-06-10 - 摘要：This paper presents an antibody network approach for vehicle detection from high resolution satellite imagery.This approach regards the vehicle detection procedure as a procedure that antibodies recognize danger antigens,where vehicles are "dangerous antigens" and vehicle detection templates are "antibodies".In this paper,some vehicle images are collected as learning examples,and an antiboby network is proposed to learn optimal "antibodies",which can be used to detect vehicles through the proposed matching algorithm.Experiments on Quickbird satellite images are given to show the feasibility and performance of the proposed approach.关键词：antibody networks;danger theory;vehicle detection;high resolution satellite imagery
- 152
- |
- 341
- |
- 4
发布时间：2021-06-10 - 摘要：This paper focuses on grain production loss caused by Wenchuan Earthquake.The damage of the cultivated area as well as the yield of winter wheat has been assessed.In order to estimate winter wheat acreage damaged by the earthquake,air-borne CCD images and IRS P6 LISS4 MN data were used.Damaged arable land were extracted by photo interpretation,while winter wheat proportions were collected by ground survey using GVG instrument for plain area or interpreted from airborne images for mountain area.The winter wheat acreage damaged by the earthquake was calculated using winter wheat proportion multiple the area of damaged arable land and statistic at county scale.To estimate wheat yield,reliable agro-meteorological models were selected by taking into account the disperse distribution of winter wheat in mountain area.The results showed that only about 247.1hm2 of winter wheat were damaged in the twelve main producing counties and the production loss of winter wheat was estimated to 1013778kg.As conclusion,the earthquake did not significantly affect the food production of the whole country.Nevertheless,since all farmers were evacuated in mountain area after the disaster,the problems of harvest in that region producing 220000t of winter wheat need to be addressed.关键词：Earthquake;grain;loss;remote sensing
- 188
- |
- 523
- |
- 4
发布时间：2021-06-10 - 摘要：Archaeological remote sensing is the archeological research using remote sensing data as data sources,and at present it is mainly used to investigate the distribution of archaeological sites and predict the existence of above ground or the underground ancient relics and their distribution pattern of detection,the space mapping of the ancient ruins,and the virtual recovery of ancient monuments and their background.Remote sensing technology is able to quickly and efficiently find the distribution of information of ground and underground ancient relics.It plays a significant role in the present archaeological research,and has increasingly become an essential process in large-scale archaeological investigation,especially pre-site inspection.Significant progress has been made in archaeological field investigation due to the rapid development of remote sensing technology,as well as the emerging of the new goals of archeology,the new needs and the applications of remote sensing technology.This article reviews the history of archaeological remote sensing,and introduces the advantages and roles of remote sensing technology in the detection of large-scale sites,and some research instances such as the current archaeological remote sensing and virtual archaeological research,and finally surveys the problems in the development of archaeological remote关键词：remote sensing;archeology;grand site
- 150
- |
- 2649
- |
- 8
发布时间：2021-06-10 - 摘要：Chlorophyll fluorescence（CF） has become a powerful tool in plant photosynthesis research and stress detection.These types of methods have been mostly relegated to the laboratory.Recently much attention has been paid to chlorophyll fluorescence sensing for the remote estimation of plant physiological status.Remotely sensed chlorophyll fluorescence emission has a potential to become one of the major global-scale reporter signals on vegetation performance and stress.In this paper,firstly,laser induced fluorescence sensing was presented,including a brief introduction,plant fluorescence spectral characters and some applications for stress detection.An overview was then given to the developments of solar induced fluorescence sensing,including methodology for the retrieval of vegetation CF from apparent reflectance（vegetation indices and FLD） and applications for monitoring plant health.Finally,the future development trends and the prospect of active and passive remote sensing of chlorophyll fluorescence were discussed.关键词：chlorophyll fluorescence;remote sensing;vegetation
- 314
- |
- 2271
- |
- 11
发布时间：2021-06-10
- Postal code：100190
- Tel：010-58887052 Email：nrsb@aircas.ac.cn
- Technical support is provided by Beijing Founder electronics co., LTD 京ICP备20021838号-9
京公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
0