Remote sensing technology can be applied to the appraisal of land reclamation engineering.
Land reclamation and coordinate was inrtoduced.The stady area was selected and the relevant data were collected and analyzed.The images were processed and interpreted,the appraisal system was built up and the result met with the requisition.The veracious result shows the feasibility of this means.
With the advancement of remote sensing technology,many methods based on remote sensing have been developed to calculate regional evapotranspiration.SEBAL model is based on land surface energy balance and its physical meaning is clear.Evapotranspiration amount can be inversed by using remote sensing images and little meteorological data (wind velocity and air temperature).Landsat data has abundant spectral information,high spatial resolution and stable data resource; it is ideal data for inversion evapotranspiration through remote sensing technology.If parameters of SEBAL model can be accurately and exactly estimated,the inversion precision will be high and can meet the need of hydrology,ecology and forestry study and application.This paper analyzed the process of inversion evapotranspiration through SEBAL and Landsat TM/ETM+ data in detail,and summarized the previous research results,then estimated the parameters of the SEBAL model.This study can provide certain guide for the wide application of SEBAL model in the calculation of regional evapotranspiration amount.
The difference between the spectral reflectance curves of healthy and diseased larch canopies is obvious.In this work,we chose the larch plantations as the study object.Firstly,we selected 14 larch canopy samples and measured their spectral reflectance and photosynthetic pigment contents.Then we selected 8 spectral parameters to set up a series of linear regression models.The results show that 3 remarkable different regions occur in the visible and near infrared bands.The correlation between the spectral parameters and the photosynthetic pigment contents are good except the parameter REP.The R2 values of the single-variable linear regression models for estimation of the contents of total chlorophyll,chlorophyll a,chlorophyll band carotenoid are 0.8428,0.8758,0.7498 and 0.7897 respectively.The multivariable regression models were also set up and their performance was better than the single variable regression models.The R2 values of the multivariable regression models for estimation of the contents of total chlorophyll,chlorophyll a,chlorophyll b and carotenoid are 0.885, 0.910, 0.839 and 0.862 respectively.This work provides an approach for the retrieval of the forest canopy photosynthetic pigment contents by using hyperspectral data.
Currently,there were lots of methods on urban impervious surface researching,such as Linear Spectral Un-mixing method,Non-linear Spectral Un-mixing method,Matched Filtering method and so on，however, among all these methods the Linear Spectral Un-mixing method was applied popularly and wildly by the researchers.The Linear Spectral Un-mixing method based on Linear Spectral Mixing Model (LSMM) and obtained the proportion of each land types in each pixel through un-mixing each pixel in the remote sensing image.This paper used Purity Pixel Index (PPI) and manual selection method to select end-member and gained the abundance images of each end-member in each pixel and the RSME image by using linear spectral un-mixing method.At last,it obtained the impervious surface weight image of 8 areas in Guangzhou.Besides,this paper analyzed the two end-member selection methods and evaluated the precision of the result from the qualitative standpoint.The result revealed that the method could abtain the impervious surface weight image of 8 areas in Guangzhou efficiently and the manual selection method could gain the weight image with more precision than the PPI method.
Soil moisture is an important variable in hydrology,meteorology and agriculture science.In this study,two Landsat TM images of Xiamen city were used to evaluate soil moisture of the city for the years of 1989 and 1996.The extraction of the moisture was based on a spectral feature space composed of fractional vegetation cover and land surface temperature.Furthermore,the change of soil moisture of Xiamen city during the study period was also detected.The study revealed that the moisture of the downtown area in the southeast of Xiamen has increased,while the moisture in the north area was significantly reduced,which is due largely to the urban expansion to this area during the period.
Taking Beijing area as an example,the aurban surface aerosol optic thickness has been tried to retrieve using DDV (Dark Dense Vegetation) method from MODIS level1B data. Firstly, the LUT (Look Up Table) is built by 6S, the dark dense pixel is checked based on NDVI and the retrieved AOD (Aerosol Optical Depth) is validated using the CE318 measurements from AERONET (Aerosol Robotic NETwork). The results show the DDV method can be used to monitor the urban aerosol very well during the summer and autumn in Beijing, but it losses its power in the winter.
For the investigation of land use and land cover change,taking the limitation of optical remote sensing in rainy or cloudy regions of China into consideration,synthetic aperture radar (SAR) can be an alternative way.In this paper,we first introduce an object-oriented imagery segmentation and classification software named Definiens Developer for the land use classification of single polarization spaceborne SAR images,including median resolution spaceborne SAR( take ENVISAT ASAR and Radarsat-1 as examples) and high resolution spaceborne SAR(take TerraSAR-X as an example).Then,we estimate the classification accuracy and analyze the potentials for the two modes spaceborne SAR images in the classification of land use and land cover change.In this part,conclusions for the interpretation of their corresponding SAR images are also given.
For meeting the demand for large-scale agricultural monitoring system with remote sensing technology,extracting paddy rice information on the remote sensing image must be rapidly,precisely and reliable conducted.In this paper,paddy rice identification with SPOT-5 image was taken as an example on the 852 farm in Heilongjiang province of China.Firstly,the spectral characteristics of paddy rice and other six land-use types in this area were analyzed to find the possibility of extracting of paddy rice from the background.The results show it is difficult to distinguish paddy rice information from background on the SPOT-5 images because of complexity of spectrum and lack of band information.Secondly,taking those into account,characteristic bands for paddy rice extraction were proposed and merged into SPOT-5 images in order to increase spectral information and improve the separability.Thirdly,a simple model of decision tree was applied to extract paddy rice information.Finally,the results were checked by visual and statistica1 accuracy assessment.The results suggest that the model based on characteristic bands is simple and effective,and the accuracy by the model is much higher than that by the supervised classification method.However，some pixels in the neighborhood area between paddy rice and corn were misjudged.
Based on the NDVI data of different resources from Feb.2000 to Dec.2001,the difference and suitability of GIMMS-NDVI,VGT-NDVI and MODIS-NDVI responsing to the vegetation change in Ruoergai marsh were analyzed.The results showed that there was no significant difference among the three NDVI data,and the difference was mainly caused by the spectral characteristics of the sensors.The prominent sensitivity of red spectrum,removing water vapor absorption band in infrared spectrum and higher spatial resolution of the MODIS-NDVI and VGT-NDVI data,which resulted the two types data are more sensitive to the vegetation change and more suitable to the study of vegetation change than the GIMMS-NDVI in Ruoergai marsh.However,the GIMMS-NDVI has longer time series than the other two data,and will still play an important role on the study of vegetation change.
Tobacco is one of the important crops in our country and brings the significant irreplaceable effect into playing in countrywide economic growth.So the monitor and scientific management of tobacco fields is especially important to us.At present, the study of tobacco remote sensing monitoring is less both at home and abroad.In this paper, we try to obtain tobacco field and area by remote sensing with Yunan Province Hong He State Tobacco County as example.We adopt rejecting interfering tobacco field information classification method of supervision while monitoring and get an ideal result.Simultaneity, we also offered the suggestion of further improving classification precision.
Water was the crucial factor that kept wetlands stable and health,to fast and accurately extract wetlands water body using remote sensing imagery became an important wetlands investigation,research and protection method.Considering the middle spatial resolution and high spectrum resolution,high positioning accuracy and low price,TM remote sensing imagery would be one of the main data for wetlands investigation,research and protection.The research carried out an experiment of extracting water from inland limnetic wetlands using TM remote sensing imagery based on many arithmetic,and concluded that spectrum classification was the best among the area accuracy index,extraction accuracy index and visual effect index,the following was single band threshold and vegetation index method,however,multi-band relationship and water index method was the worst.The main negative factor that affect extraction result was that wetlands water couldn't be extracted absolutely,which was caused by the resolution of imagery and complex hydrology condition of wetlands.Therefore,pixel unmixing and multi-source remote sensing data fusion would be the important techniques of promoting water extraction accuracy.
Land saltilization is a very important symbol of soil deterioration.It demands a lot of human efforts,materials and time to have an extensive study.While by remote sensing technology,the exact information about salted land distribution can be obtained in an efficient way at a low cost.After establishing a training sample,through the IRS-P6 saltilite photography,based on the pictures which are classified according to maximum likelihood,this essay analyzes the distribution of salted land in Hetao irrigation area of Inner Mongolia and gives an intensive evaluation.
This article take the vegetation net primary productivity NPP remote sensing estimation and the analysis as the research content, take the geographical and ecological knowledge as the foundation, uses the RS, GIS technology method, comprehensived the multiple source informations as remote sensing spectrum data, the DEM data, the statistical data, the locating point measured data and so on, have constructed the NPP remote sensing topographical model in, calculates the Xiaerxili nature protection area vegetation NPP in July. Its final goal is to complete Xiaerxili nature protection area vegetation net primary productivity quantitative.
Taking Chaohu Lake as an experimental site,unify the orbit water quality monitor data,using the simple regression and multivariate regression,the semi-empirical models for determinating chlorophyll-a concentration in Chaohu Lake are developed by relating the MODIS 250 meter resolution wave band combinations to chl-a measurements.Then,the distribution of blue-green algal bloom in Chaohu Lake is mapped.The intensity,place and distributed scope of this blue-green algae bloom reflected clearly.The results of this study show that MODIS image data is useful in Monitoring blue-green algal bloom in Chaohu Lake.The ratio of band 2 to band 1 (r2/ r1) with 250m resolution is suitable to retrieve chl- a concentration because it is well related with chi-a measurements(R=0.9093).
Water-vapor in the atmosphere is one of the major factors which affect the weather changing and the application of remote sensing.This paper introduces theories of two-channel and three-channel ratio methods for retrieving water-vapor.Detailed analysis and results are given in this paper.Two retrieving ideas are mixed and a better solution to the weighted average problem is given using the NASA document.Good results are achieved and may have some guidance on precipitation production practically.
Heat island effect is an important program for research of urban environment and climate.In this
paper,based on TM data of Nanjing of 2003,mono-window algorithm is used to extract the temperature in-
formation of urban surface.And next,we can get the condition of heat islands distributing,also find out the
masses of heat islands which have far-reaching effects on the environment and climate.On the other hand,
based on NDBI and NDVI exponents,the buildings and green space information is extracted in order to ana-
lyze the relativity between heat islands distributing and the land exploiting.We can draw a conclusion that
the heat islands most are located where the underground surface is hard one and has a dense population or
high developed industry.Meanwhile,vegetation surrounded by the buildings are playing a more patent role
on decrease the surface temperature than grass spaces.
Support Vector Machine (SVM) has excellent performance in classification.The Gray Level Co-occurrence Matrix (GLCM) is a promising method for texture analysis.Texture is an important feature in Synthetic Aperture Radar (SAR) image.So the arithmetic of texture classification by SVM was investigated, using GLCM to extract features.Compared to the method using image's gray information directly for SVM classifying, the experimental results show the feasibility and effectiveness of the new method.
Based on the boresight model for the Dual\|antenna Airborne InSAR,the outside calibration was researched by adopting sensitivity equations.The error model based on sensitivity equations was educed by differentiating InSAR imaging equations.Then the biases of interferometric parameters were solved by several accurate Ground Control Points(GCPs). The calibrated interferometric parameters were calculated by iteration method.And the accurate Digital Elevation Model (DEM) was reconstructed.Then the ground points were oriented.A set of InSAR data was adopted to do calibration experiments,which was derived by the Airborne InSAR system researched independently by Institute Of Electronics,Chinese Academy Of Sciences.The experimental results show that this algorithm is efficient.
Considering the characteristic of hyperspectral image,we have proposed a segmentation method based on region active contour.The energy function in Chan-Vese method is improved and both spatial and spectral information are employed.Spatial term of the function is restricted by global spatial information and the consistent intensity in homogeneous region; while spectral term is restricted by the consistent spectrum of target.Finally the image is segmented by minimizing the energy function.This algorithm can extract indistinct contours of hyper- spectral image,and thus reduce the influence caused by mixed pixels and the shadows around the target.Numerical experiments are conducted on AVIRIS data.Results show that this method reaches satisfying effects in performance and adapts to complex scene in some degree.
The quality of interferogram will directly affect phase unwrapping,so interferogram filtering,which eliminate noise and improve quality of interferogram,is an important step of InSAR.In this paper,we studied several filter methods used in InSAR,including azimuth and range direction filter,multi\|look filter,medium filter,gradient-based adaptive filter and Goldstein adaptive filter.
The international Charter about space and major disasters,which is initiated and established by Europe Space Agency (ESA) and French Space Agency (CNE) in 1999,is the first and unique international organizations that practically operated via the space technology for Earth observation to mitigate the effects of disasters so far.This paper presents the development and the operating mechanism about Charter,and reviews its function,contribution and significance through some activation cases using Charter and the international space resources in Anhui and Sichuan provinces and Chongqing city seriously affected by the flood after CNSA (China National Space Agency) joined the Charter.
