The Technology Research Of Relief Shading Based On ZY-3 Stereo Images

Relief is one of the most basic elements of geographical environment,and it is a general term for various natural forms of the earth’s surface and terrain undulating change.It not only restricts the spatial distribution of geographical elements,but also greatly influences the development of humanistic elements.Relief can be represented by hachuring,description method,shading,contouring and hypsometric tinting.Among them,the shading method is the most commonly used and intuitive terrain representation.DenisWood,a scientist at the map,quoted Lynam Edward as saying: " The expression of mountains is always the most difficult problem for mapmaker".Therefore,it not only has a very important significance in the field of cartography but also has been one of the hot issues in the study of mapmakers for the study of how to express 3D terrain in the two-dimensional plane map effectively and intuitively.Based on the applicability analysis of stereo images of ZY-3 satellite,this paper selects the DEM generated by stereo images of ZY-3 satellite as basic data,focuses on the digital relief shading technology.What the research in this paper concerns lists as follows:(1)This paper systematically summarized the relevant theory of relief shading.It describes the basic principle of shading generation and illumination model,to investigate the effect of topography on shading and division method of national relief area,the representation of topography at different scales is analyzed.(2)Study on the technology of the digital relief shading.Based on the applicability analysis of stereo images of ZY-3 satellite,the key technologies of ZY-3 satellite stereo images generation DEM are given,we discussed different processing methods of DEM data of shading map making in order to improve effect of shading.(3)This paper mainly researched technology of digital relief shading.From the point of view of different landform type,the influence factors of shading effect were analyzed and discussed;Analysis and comparison are given for different shading method;By removing topographic details,geomorphic feature enhancement and the shaded area adjustment method,the shading effect of optimization of related research;Study on optimization of the shading effect by removing topographic details,geomorphic feature enhancement and the shaded area adjustment method;On the basis of color model,established the basic method of color hill shading map design,and the application is analyzed and summarized.(4)Finally,the analysis and evaluation are carried out with specific examples,the results show that technical methods of above research applied to the shading map can meet the requirements of drawing on shading.Compared with other landscape representations,shading method is a method of the most commonly used and three-dimensional sense of strong,it has gradually closer to practical direction.Based on the applicability analysis of stereo images of ZY-3 satellite,this paper selects the DEM generated by stereo images of ZY-3 satellite as basic data,focuses on the digital relief shading technology.The research of this paper has a strong practical value and operability,and it can provide some reference ideas and methods for mapmaker and map product department.