The Researches On Quality Evaluation Methods Of 1:50,000 DEM

DEM has become one of the 4D products of special digital infrastructure,the important database in GIS,basic data for geographic analysis.1:50,000 DEM is the most intact and precise DEM data.It is the one of widest-applied DEM data at present.Due to the shortage of the support of relevant DEM quality evaluation method,at present we cannot clarify the data quality of the topographical information actually contained in the 1:50,000 DEM,This leads to the dilemma that there are data that could be used in the application of 1:50,000 DEM and there are urgent demands for these data,but the user side has no idea about the effect and impact of application of the data.Research on how to evaluate the 1:50,000 DEM data quality has become an urgent task.This thesis systemically researchs the related theory of the DEM quality evaluation to the present actuality and main problem of the DEM quality evaluation,deeply resaechs the methods of the quality evaluation by linking the reality of 1:50,000 DEM.1,Researchs on the DEM quality evaluation.Analyses all kinds of errors and characters of DEM,establish contents and measurement index of DEM quality evaluation,establish 1:50,000 DEM uncertainty conceptual model.2,Analyses the actual quality and precision of 1:50,000 DEM Data on an experimental method.Analyses the interpolation arithmetic of the production of 1:50,000 DEM.Analyses the adaptability of the interpolation arithmetic to typical terrain on an experimental method,based on GPS,control point data and analytical photogrmmetry produce DEM data synoptic analyses the precision and quality of 1:50,000 DEM date,analyse the rationality of 1:50,000 DEM grid interval.3,Rresearchs on 1:50,000 DEM quality evaluation methods.Introduces and analyses the DEM quality evaluation methods in existence.This thesis raiseses several quality evaluation methods with assistance of some data or related knowledge.Researchs on evaluation method of 1:50,000 error distribution,measurement and elevation quality basing on reproduct contour raster map.Researchs the elevation quality evaluation method of combining rate of disfigurement statistic and check points.Researches on the DEM edge mathching quality evaluation method basing on section plane.4,Designs and achieves the DEM quality evaluation system.