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1.
一集等面积类圆柱投影   总被引:1,自引:0,他引:1  
提出了一集等面积性质的类圆柱投影。  相似文献   

2.
正弦经线等面积伪圆柱投影族的研究   总被引:1,自引:0,他引:1  
乔俊军 《地图》1994,(4):30-34
本文在分析了现有正弦经线等面积伪圆柱投影族(B=0)的基础上,提出了一种更为概括的公式。并证明了若干已有投影仅是其特例。  相似文献   

3.
本文指出了地图投影分类系统中还有若干\  相似文献   

4.
构建了一个纬线表象为平行于赤道的直线,经线表象为对称于中央直经线的双曲线,且面积没有变形的投影集合,并得到一组概括公式。该公式不仅包括了克拉斯特创建的经线交于极点的双曲经线等面积伪圆柱投影,而且也包括了经线交于极线的双曲经线等面积伪圆柱投影。  相似文献   

5.
椭圆等面积伪圆柱投影在中高纬度与远离中央经线地区角度变形较大是限制该投影应用的主要原因,因此改善角度变形是该投影研究的重点。本文根据椭圆等面积伪圆柱投影的原理,进一步完善了椭圆等面积伪圆柱投影族公式,并依此求得经线投影为椭圆中心不在坐标原点的非标准椭圆等面积伪圆柱投影,通过该投影与投影族中其他常用投影的变形对比,表明该投影的角度变形得到了改善;最后对该投影在我国世界全图数学基础设计中的适用性进行了分析。  相似文献   

6.
等面积投影的仿射变换及若干改良等面积投影的探求   总被引:1,自引:0,他引:1  
杨启和 《测绘学报》1992,21(1):67-77
本文探讨了等面积投影仿射变换的理论和方法。包括:仿射变换等面积投影坐标,仿射变换面积元素的一般方法,并对一些常用的等面积投影进行了仿射变换举例。从等面积投影仿射变换中可得到具有很大实用价值的改良等面积投影,其具有很大的概括性和灵活性,在地图设计和计算机屏幕地图设计中有着广阔地应用前景。  相似文献   

7.
一种正弦等面积伪圆柱投影族   总被引:1,自引:0,他引:1  
张顺卿 《地图》1991,(2):50-51
伪圆柱投影是一种广泛用于小比例尺地图的投影,特别是制作全球地图时多用此投影。本文在分析等面积伪圆柱投影基础上,提出了一种概括公式。一、B=0的正弦投影族的一般公式经线形状为正弦曲线的等面积伪圆柱投影,其公式为:  相似文献   

8.
等面积多圆锥投影在地图投影分类中目前还是一个"空白".根据等面积投影条件,推导出了等面积多圆锥投影的坐标和变形计算公式,并对该投影的变形特点进行了分析.结果表明,等面积多圆锥投影适合制作中、高纬度地区沿南北方向延伸区域的地图,也适合制作世界地图和地球仪.  相似文献   

9.
已经证实,太阳系中大约有近一半的星体是不规则体,如果我们要用地图来描述、显示这些形体,那么就需要一种能精确描述这些形体的投影方式。然而,目前还没有一种严格的数学途径来实现对不规则体的等角或等面积投影。本文提出了一种新颖的方法,用此方法可以实现对不规则体的严格的等面积投影,使用这种方法,已经实现了对火卫一星和火卫二星(火星的2个卫星)的等面积投影。  相似文献   

10.
11.
Many small solar system bodies such as asteroids or small satellites have irregular shapes, often approximated by the reference surface of a triaxial ellipsoid. Map projections for the triaxial ellipsoid are needed to present the incoming data in the form of maps. In this paper the formulae of equal-area cylindrical and azimuthal projections of the triaxial ellipsoid were derived and practically implemented for the first time using as an example the asteroid 253 Mathilde. This paper is the final in a series of papers devoted to all main classes of projections of the triaxial ellipsoid. Before this, the authors obtained equidistant along meridians projection and Jacobi conformal projection for the triaxial ellipsoid.  相似文献   

12.
一种通用球面等积离散网格生成算法   总被引:5,自引:0,他引:5  
球面离散网格模型是管理海量数据的有效途径,如何构建球面网格是这类模型的基础问题.文中利用Snyder等积多面体投影建立了平面与球面的对应关系,设计了球面等积三角形和四边形离散网格的生成算法.结合实验分析了两种网格的最大/最小边长比和单元周长均方差两项指标,结果表明全部网格的指标均收敛,适合用作多分辨率地理空间信息的管理.  相似文献   

13.
A series of new equal-area map projections has been devised. Called Oblated Equal-Area, its lines of constant distortion follow approximately oval or rectangular paths instead of the circles of the Lambert Azimuthal Equal-Area projection or the straight lines of the Cylindrical Equal-Area projection. The projection series permits design of equal-area maps of oblong regions with less overall distortion of shape and scale than equal-area maps on other projections.  相似文献   

14.
ABSTRACT

Sometimes map projection designers need to create equal-area projections to best fill the projections’ purposes. However, unlike for conformal projections, few transformations have been described that can be applied to equal-area projections to develop new equal-area projections. Here, I survey area-preserving transformations, giving examples of their applications and proposing an efficient way of deploying an equal-area system for raster-based Web mapping. Together, these transformations provide a toolbox for the map projection designer working in the area-preserving domain.  相似文献   

15.
为了获得形式多样的地形可视化效果,投影方式的选择至关重要,通过对正投影、透视投影、渐进式投影和平斜投影等多种投影方式的原理与方法进行研究,分析了各种投影方式的适用性及其获得的地形可视化效果,为应用实践提供了有益借鉴。  相似文献   

16.
对施奈德等积多面体投影的研究   总被引:2,自引:0,他引:2  
提出了先确定边界、再逐步精化的研究思路,系统、直观地阐述了投影的基本原理,并推导了严密的变换公式,在此基础上给出了详细算法和部分实验结果。  相似文献   

17.
Equivalence (the equal-area property of a map projection) is important to some categories of maps. However, unlike for conformal projections, completely general techniques have not been developed for creating new, computationally reasonable equal-area projections. The literature describes many specific equal-area projections and a few equal-area projections that are more or less configurable, but flexibility is still sparse. This work develops a tractable technique for generating a continuum of equal-area projections between two chosen equal-area projections. The technique gives map projection designers unlimited choice in tailoring the projection to the need. The technique is particularly suited to maps that dynamically adapt optimally to changing scale and region of interest, such as required for online maps.  相似文献   

18.
An adaptable equal-area pseudoconic map projection   总被引:1,自引:1,他引:0  
Equivalence (the equal-area property of a map projection) is important to some categories of maps. However, unlike conformal projections, completely general techniques do not exist for creating new, computationally reasonable equal-area projections. The literature describes many specific equal-area projections and a few equal-area projections that are more or less configurable, but flexibility is still sparse. This work describes a new, highly configurable equal-area projection system consisting of arcs of concentric circles, placing it in the pseudoconic class. The system uses a novel technique to hybridize the Bonne pseudoconic projection and the Albers conic projection, subsuming many existing projections as degenerate cases. With the resulting system and the technique used to develop it, map projection designers will have greater choice in tailoring the projection to the need. The system may be particularly suited to maps that dynamically adapt to changing scale and region of interest, such as required for online maps.  相似文献   

19.
GIS以表示地理信息的数据库为核心 ,以同时描述空间数据和属性数据为最基本的特征。将不同尺度、不同时期、不同来源的地理数据精确定位于公共的地理基础之上 ,是实现GIS目标的基本要求。不同投影之间的互相转换以及投影类型或参数的选择对GIS数据的输出结果有极大影响。本文通过对地图投影的分类、经纬线特征、变形分布的分析 ,探讨了GIS中地图投影的变换和选择方法  相似文献   

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