| The Gauss-Kruger projection(Gaussian projection for short)is an isometric projection,which is a projection of an ellipsoidal cylinder cut at an isometric transverse axis.Gaussian projection is widely used in many countries and regions because of its small area distortion,simple calculation and high projection accuracy.The coordinate systems commonly used in China(Beijing 54,Xi’an 80,CGCS2000)and the independent coordinate system of each city are Gaussian projections.Gaussian projection cannot avoid length and area deformation.The Gaussian projection has more research on length deformation and has gradually matured,but it involves less on area deformation and needs more in-depth research to enrich the results of area deformation and provide reference for future geographic information work related to area deformation reference.This article introduces the basic theories and methods of the shape of the earth,China’s common coordinate system,map projection and Gaussian projection.Taking the 36 belt of Guizhou Province as the research area,the latitude direction is divided from the latitude of 24 ° at a latitude interval of 15′;the longitude direction is taken from a longitude of 108 ° at a latitude interval of 15′.The latitude and longitude lines form21×14 square grids.Based on the CGCS2000 reference ellipsoid,taking the 1′× 1′ southwest corner of each grid as the research object,thereference ellipsoid surface area and the Gaussian projection plane area are calculated.The ratio and difference of areas are used to study the deformation law of Gaussian projected area under the same coordinate system.The paper discusses the influence of the latitude and the distance from the central meridian on the deformation of the Gaussian projected area and the law of the Gaussian projected area under different coordinate systems.Finally,a solution to the Gaussian projected area deformation is proposed,and Comparative analysis of the results through data. |
PDF Full Text Request