Crop residue burning has a great negative impact on the ecosystem and environment in China.Remote sensing can provide abundant information of surface fire and thus support the government to forbid the crop residue burning effectively.Although "Contextual Fire Detection Algorithm" is an automatic fire-detecting algorithm with good accuracy,its fixed parameters and thresholds can not perform well in detecting fires of different kinds or in varied situations.Therefore some of the key parameters are adjusted according to the practical observations,in order to better monitor the surface fire in China.On the basis of data from EOS/Terra-MODIS,the crop residue burning in North China has been monitored from May to August in 2007,the accuracy of which can satisfy the requirement of practical applications.In addition,based on the IGBP classification data,the detected fire pixels are separated into 3 types of biomass burning,namely crop residue burning,forest fire and grass fire.Then the statistics and analysis of several parameters of the 3 types of fire are implemented respectively,on the basis of which the possibility of identifying the type of fire pixels according to their radiant characteristics is discussed.It is concluded that surface classification data is still necessary when identifying the fire pixels.
The cellular automaton model has the ability to simulate the process of two-dimensional space evolution in discrete time.Therefore it is dynamic in time and space.The characteristic makes it greatly superior in simulating urban growth.The paper explained the parameters,transformation and rectification of the SLEUTH model-one specific realizid format of the cellular automation model,what'more,the author modified urban growth rule and parameter setting of this model in order to improve simulation accuracy.On the base of which,the process of urban growth of Changsha city between the year 1996 and 2005 is rebuilt.Moreover the spatial morphology of Changsha city in 2010 is separately predicted with the method of scenario simulation.The results showed that application of the SLEUTH model to simulation of urban growth is advisable.
Soil Moisture and Vegetation Growth are the most important and direct index in drought monitoring,and the spectral interpretation of vegetation and soil are serious factors in the judgment of drought degree.Based on the spectral character of water,recently,a new model of Surface Water Content Index(SWCI) has been put forward,and the index is more sensitive to the surface water content,and suit for regional drought monitoring.The comparative analysis showed that SWCI is more sensitive than NDVI to monitoring surface soil water content,it is available in real-time soil drought monitoring.
A novel method is presented for oil spill detection in synthetic aperture radar (SAR) images,which is based on the constant false alarm rate (CFAR) technique and considers the probability density function of sea clutter as Gaussian distribution.All possible oil spills are detected using an overall threshold,which is calculated using the analytic formula.Then a statistic filter is used to eliminate the false oil spill pixels.This method avoids complicated iteration,calculation of shape parameters and dichotomy threshold,and therefore its accuracy and computation speed are improved,which are demonstrated by the results.In the paper,the main techniques for oil spill detection in SAR images are reviewed.A novel method is presented,which is based on CFAR technique and Gaussian distribution of sea surface clutter.In this method,CFAR operator is given based on Gaussian distribution (normal distribution),and the statistic filter is introduced to eliminate the false oil spill pixels,finally the framework of the method is described.The ASAR images are used for the algorithm test.Parameters such as detection threshold,computation time,etc.Results and comparison show that the new method proposed in this paper has advantages of high accuracy and computation speed.
By using three-period (1976,1996,2006) remote sensing images and under the support of RS and GIS techniques,spatial information of land desertification in Guinan county was interpreted and extracted,and the spatio-temporal pattern of desertification information change was analyzed in this paper.The analyzed results indicated that:①The degradation land account for 42.6%、58.6% 、56.8% of the total land area in 1976,1996,2006 respectively in Guinan County,Qinhai Province.In the past 30 years,the desertification land area in Guinan county was increased by 14.19%,with the average annual increase percentage of 0.47%,indicating that the land desertification in Guinan county was aggravated as a whole.②In Guinan county,the main reasons causing land desertification were the erosion derived from wind force and water force,and the main grade of desertification land was moderated grade and severe grade desertification.③During 1976 to 1996,the analysis for dynamic degree showed that the land desertification was severe,especially unimportant grade desertification land area increased fast,and in the period of 1996~2006,the severe land desertification situation began to transfer to good situation.The main reasons causing the generation and development of land desertification of Guinan county included natural factor and human actions.
The measure and analysis of the spectrum of vegetables is very important for applying remote sensing in identifying vegetable.The spectrum data of the different vegetables such as Chinese cabbage,garden pea,cattle vegetable,verdure,garlic,onion,parsley are gotten by using SE590 hyper\|spectral radiometer in Tengchong county of Yunnan province.The spectrum curves of the vegetables are made based on the spectrum data.The spectrum feature is analyzed based on the spectrum data.The first order derivative transfer was carried out in the spectrum data.The first order derivative feature is analyzed.It is shown that:The vegetables can be divided into two groups according to their reflectivity during 400nm to 679nm.The first group with higher reflectivity includes Chinese cabbage,garden pea,cattle vegetable,verdure.The second group with lower reflectivity includes onion,garlic and parsley.Each vegetable can be differentiated from each other according to the peak value,valley value and slope of their spectrum curves,and their reflectivity value in the first group.Each vegetable can be differentiated from each other according to their reflectivity values during 726nm to 1 100nm in the second group.The unique first order derivative feature can be used to identify Chinese cabbage,garden pea,garlic,onion and parsley.
The Split-Window Algorithm is the most commonly method for Land Surface Temperature (LST) retrieval with the Remote Sensing of Thermal Infrared.The paper build a Split-Window Algorithm based on the MODIS which is suitable for LST retrieval in Arid / Semi-arid regions and verify them with the same period of MODIS Land surface temperature products which is released by LP DAAC and the corresponding 53 meteorological observations data.By analyzing the accuracy of this model is the same as the accuracy of MODIS LST products and the meteorological observation data.The results can show LST characteristics of spatio-temporal changes in Arid/Semi-arid regions.
Different classification in wetlands is synthesize to classify by remote sensing.Through analyzing trait of the spectrum symbols,different parameter change,space configuration's difference,land-cover's seasonal variability and so on.Different wetlands types adopt different method to distinguish,lastly a synthesis classification method from easy to hard is established effectively.A typical case from PoYang lake.Classification using by this method cann't only lighten a mass of people's work but also improve classification's precision.
This study used a spectrometer and the above-water sampling method to measure the water's optical properties of the Jin River.The correlation values between high spectral resolution reflectance data and suspended solid concentration (SSC),or between the first derivative of high-resolution reflectance and the SSC showed that the wavelength around 733±3nm was the best one for estimating the SSC of the Jin River.The regression analysis using several regression models revealed that the quadratic polynomial model was the best one to estimate the SSC of the river.It also found that the single-band regression model is more suitable than the first derivative regression model for estimating the SSC of the Jin River.
S301,which joins Naqu and the Ngari area,east meets the Qinghai\|Tibet railway,the Qinghai\|Tibet highway in the National Highway G109 and the north line of Sichuan\|Tibet highway in the National Highway G317,west meets the Xinjiang\|Tibet highway in the National Highway G219,is one important channel for Ngari area.The area which the road through distributes lots of lakes.With global warming,glaciers melting and permafrost degradation,the rising of lake water level brings many potential trouble and disaster to the highway.A better understanding of the lake variations is important for the road.The remote sensing technique is an efficient tool to analyze the status and variations of lakes.The study use topographic maps,aerial photographs,Landsat TM images,and compilations of other relevant data to analyze the changes of the lakes near S301 highway on the Plateau from 1970 to 2000,and to study the impact of the lake changes on the road.The results shown most of the lakes expanded and have affected the safe of the S301 highway.
In this paper, 2006 TM image of Liangping is used to land use interpretation.The objective is to analyze and evaluate various impact factors on urban-rural planning land suitability via GIS-based Spatial Analysis method, to construct comprehensive evaluation model of urban-rural planning land suitability (Weighted sum model) and to incorporate the evaluation model to comprehensive land use suitability assessment in the region of Liangping.
Lake color is an important index of water optical properties.Because of its special geographical conditions,color of lakes in Qinghai-Tibet Plateau is significantly different.In this paper,Mapangyongcuo Lake and La'angcuo Lake in the south of Tibet were chosen as research.Starting from the image representation of the two lakes' color,remote sensing technology was used to analyze the differences.As shown in the results that,evaporation and recharge of the two lakes were different,so the substance deposition such like salt were different,and then influenced the lake color.This is a new method to research on lakes in Qinghai-Tibet Plateau that are lack of observed data.
Based on the two remote sensing TM images of Xi'an city in 2000 and 2007,through the maximum likelihood method,geographic information systems and spatial analysis methods and mathematical statistical methods by using Erdas Imagine 9.0,ArcGIS 9.2 and Matlab software platform,we calculated type of land use in Xi'an dynamic transfer matrix and then constructed the land use change index,type of land use change and more important index of regional land use change,such as the exponential model,quantitative analysis of spatio-temporal changes of land use in Xi'an so as to analyse spatio-temporal changes of land use in Xi'an.The revealed differences and changes of land use in the main types of space and regional distribution of direction will clarify a land-use change in Xi'an regional characteristics which in turn can help us making excellent decision in sustainable use of land.
Remote sensing data from Landsat 5 were utilized to assess urban area thermal characteristics in Lanzhou.Estimating urban land use extents and development densities,a major component of the vegetation-impervious surface-soil(V-I-S) model and the Linear spectral mixture analysis method are used to define the different threshold values.According to impervious surface fraction,the urban area is reclassified for four categories.Analysis results show the urban area of Lanzhou has a daytime heating effect.These thermal effects strongly correlated with urban development densities.Using vegetation canopy coverage information,the spatial and temporal distribution of impervious surface and associated thermal characteristics are demonstrated to be very useful sources in quantifying urban land use,development intensity,and urban thermal patterns.
In this paper,EOS-Terra/MODIS data is used in the study of monitoring duststorm in Inner Mongolia.By analyzing the spectral response characteristics of duststorm and the bands from MODIS sensor,the method superposition analysis based on the boundary limit values of two bands is put forward.The results showes that the superposition method based on the thresholds of two bands is an ideal method to accurately derive the information about duststorm and provides an effective means to use MODIS data.
The recent development strategies and plans on space and earth observation technology of some countries such as the U.S.,Russia,Japan and Canada,and GEO and ESA are introduced briefly.The plans or reports are as follows:Development of the U.S.Integrated Earth Observation System:Progress and Recommendations for the Way Forward,Science Plan for NASA's Science Mission Directorate 2007~2016,the Earth Observation Satellite Plan 2006~2015 in Russia,JAXA 2025, Earth Observation for a Healthy,Safe and Prosperous Canada——Towards a Federal Earth Observation Strategy and the Earth Observation Focus Areas,GEO 2007~2009 Work Plan Toward Convergence,The Changing Earth:New Scientific Challenges for ESA's Living Planet Programme.The characteristics of space and Earth observation technology in the world are analyized according to the reports.
Earth observing technology was used in civilian fields since the initial part of 1970s.Satellites ground stations are the basic establishments of earth observation system and basic source of space data,and they play the role of public data flat in national economic construction activities,and their development got wide attentions of governments.There 21 ground stations in different countries were investigated in this paper,including America,the Europe,Japan,Canada and Australia,etc.The properties,distribution characteristics,management system,personnel size and data types received of overseas satellites ground stations were analyzed in this paper.The results showed these overseas satellites ground stations had automatization,commercial,marke-oriented,civilian,internationalization,systematization,net-oriented operation characteristics.Future development direction of satellites ground stations was put forward in this paper.
3S technologies have been very important to geo-data collection, management, visualization and analysis. The Sichuan-Tibet Highway hazards information system based on RS, GIS and DBMS, and well treated some vital problems such as data organization and maintenance, data visualization and classification, multi-theme info abstraction, multi-type data integration, etc. These problems have become common features to many GIS applications. The development of The Sichuan-Tibet Highway hazards information system make the management and maintenance conveniently and quickly for the Sichuan-Tibet highway disaster information. The Sichuan-Tibet Highway hazards information system could help researchers to study and father the disasters of the Sichuan-Tibet Highway. The correlative data also could be issued on the net fo public.
FY-3 MWHS scans the Earth's surface by mechanically rotating the antenna around X-axis.This research presents a geolocation method for FY-3 MWHS' remote sensing image based its scan geometry.It creates the spatial relationship model between the sensed data and the Earth based coordinate system,according to MWHS' sensing geometry and the sensor's attitude and position.This method is also including an algorithm of satellite orbit computation,which is used to get the satellite's instantaneous velocity vector from its position vectors.This method has been applied to FY-3 MWHS' remote sensing image geolocation.The geolocation result and error analysis use the land/water mask.Compared the geolocation results with the true remote sensing image,it shows that this method for MWHS' remote sensing image achieves pixel geolocation accuracy.
Microwave spaceborne radiometer adopts sqare-law detection,so the radiation of the object received is linear to the output voltage of the radiometer.Therefore,the calibration of microwave spaceborne radiometer is performed by measuring the radiometer response to hot and cold references during operation.The hot reference is usually a blackbody under environmental temperature,and the cold reference is Cosmic Background Radiation.According to Rayleigh-Jeans law,the emission of the object is directly linear to its absolute temperature.As the frequency of object increases,Rayleigh-Jeans Law deviates from Planck's Blackbody Radiation Law,and the radiation of object received should be calculated according to Planck's Blackbody Radiation Law.The calibration equations of millimeter and submillimeter radiometer are derived from the Planck's Law,and the formulas of the calibration references radiation are presented in millimeter and submillimeter bands.
In this paper,SIFT feature is introduced into automatic registration and mosaic of remote sensed imagery and aerial imagery.Considering to the low efficiency of RANSAC algorithm and the estimation of the scale of inliers noise which refer to ,we presents a feature matching approach called projected based M-estimator to resolve the matching problem,which can escape from human-interaction in automatic system.Numerous experiments have been conducted for both aerial and satellite imageries under various conditions such as geometric distortion,illumination variation and different resolution.The result showed that our matching approach performs well and is stable,reliable,efficient and automatic.The M-estimate can achieve authentically automatic registration without human-interaction in despite of different input data with different scale of inliers noise.
In remote sensing image processing,edge extraction is our focus and difficulty.The paper showed the conception and species of the edge,and deeply explored the differential operator methods of first order and differential operator methods of second order.We contrasting and analyzing the principles and processes of every differential algorithm and the conclusion of the image processing.In the end,we bring forward our viewpoint about the problems the remote sensing image edge extraction technology is facing and where is the developmental direction of it.
Shadow detection in high spatial resolution remote image is very critical for target identification and information recovering.In this paper,an object-oriented method is used to detect shadow area.Firstly,the image is processed by segmentation to attain the image objects, then the knowledge is established according to the analysis of the spectral character of the shadow area in the image.Finally,the shadow area could be extracted by using the rules defined in the knowledgebase.The experiment result shows that this method is valid.
