Study On Two Phase Sampling Monitoring Method Of Forest Area Based On Ground And Remote Sensing

At present,the scientific and technological content and technical level of forest area monitoring in our country are constantly improving,and are already in the international advanced ranks,the means of monitoring vary from survey to survey.This paper takes Lin’an City as the research object,analyzes the main technical means and survey methods of county forest area survey,and makes use of ground sample survey data and Google Earth image,through the technical work of the remote sensing sample plot layout,the establishment of visual interpretation marks,image interpretation and so on,the ground class interpretation of the remote sensing sample plot is completed,combining the two-phase sampling technique method and using the transfer probability matrix method,the forest area was estimated,and the estimation precision was calculated.The deficiency and prospect of the research method were put forward.Based on the ground survey technology and remote sensing sampling combined with transfer probability matrix method.The remote sensing plots are densified to 1 km×1 km.0.5 km×0.5 km,0.5 km× 1 km on the basis of 2 km×2 km spacing of the ground plots,and the remote sensing plots are used as a phase sample to obtain the land class information of the remote sensing plots by means of remote sensing interpretation technology,two-phase sampling method was used to estimate the area of each area in Lin’an City.two-phase sampling was used as a subset of two-phase sampling.By means of Formula Derivation and data verification,the estimation accuracy of two-phase sampling method is analyzed,and the influence of the number of one-phase samples and the positive judgment rate of one-phase samples on the sampling accuracy of two-phase sampling method is deduced and verified,the experimental results show that the estimation accuracy can be improved effectively by using the two-phase sampling technique,but there are two-phase estimation accuracy limit values.Remote Sensing image interpretation combined with the method of estimating forest area by ground sample plots is beneficial to saving monitoring cost,improving monitoring efficiency,and providing some ideas for forest area monitoring in counties,it is helpful to establish a complete dynamic monitoring system of forest area.