Study On Remote Sensing Estimation Of Tree Height In Orchard Of Southern Xinjiang

Tree height is one of quantitatives index to reflect the growth status of trees,and it is also an important basis to reflect the quality of forest division.The polarimetric radar data can reflect the scattering characteristics of the vegetation,and it can overcome the shortcomings of high cost and difficult to obtain the tree height of other methes.In view of this,this study uses Radarsat-2 polarimetric radar data as the main data source,the canopy density was extracted from GF-1 data as an auxiliary,launched an exploratory study on the extraction method of tree height of walnut and apple orchard in Akesu,in order to find a simple,rapid and large area tree height extraction method,it provides the technical reference for the production practice of the information management and forest resources survey of orchard.The main conclusions are as follows:(1)Full polarimetric radar scattering characteristics and influence factor analysis results shows: the backscattering coefficients of SAR images of different objects show great difference under the four polarization modes,which shows that the ground features of the SAR based study area have certain separability.Moreover,the study area economic forest structure,meet the applicable conditions of the MIMICS model,canopy density and SAR backscattering coefficient has a strong positive correlation,with canopy density factor in a certain extent can weaken the influence of surface scattering,the simplified MIMICS model.(2)Based on the results of full polarization radar data tree inversion: in the coverage factor,the accuracy of actual backscattering coefficient of vegetation is higher than that of Direct inversion of total backscattering coefficient.The estimation accuracy of walnut and apple optimal model were 81.23%,89.87%.The traditional model can only be used in the study area,and it is necessary to further test the other trees and other trees.(3)The results of tree height estimation based on polarimetric interferometric SAR shows: based on the improved polarimetric interference SAR,the walnut tree overestimated measurement accuracy increased from 59.37% to 70.85%,and the apple tree increased t from 73.61% to 79.80%,Compared with the full polarimetric radar tree height estimation,the precision of the method is slightly lower,but the method is not limited by the region,and has a certain advantage in large area and macro level.