日晷投影原理及其应用  

The theory of gnomonic projection and its application

作　　者：刘群[1] 

机构地区：[1]贵州师范大学数学与计算机科学系,贵州贵阳550001

出　　处：《贵州师范大学学报（自然科学版）》2003年第3期109-112,共4页Journal of Guizhou Normal University：Natural Sciences

摘　　要：应用日晷投影原理 ,可推导出日晷上确定投影点直角坐标的一般公式 ,以及 5类有代表性的日晷的时线方程。它们的时线皆为直线。其中 3类为常见的日晷 ,其余 2类日晷新类型。文中的实例说明新型日晷的安装 ,并提出附加观测 2 4节气的装置。With the application of the theory of gnomonic projection, the general equation of the right angle coordinate on the exact point of gnomonic projection and five kinds of typical equations of denoting prjective lines of the gnomonic projecti on can be deduced. Their projective lines for denoting time are straight. Three of them are usual gnomons and two of them are new types of gnomons. Examples for installing new types of gnomons with the observing devices of the twenty-four divisions of the solar terms are given in the article.

关 键 词：日晷 投影原理 投影点 时线方程 测时仪器 天文学 日影位置 

分 类 号：P111.41[天文地球—天文学]