在中国古代地图绘制中,计里画方和山水形象画法是2个显著特色。然而,由于没有数学基础或没有明确的数学基础,使得地图定位精度大大降低,给古地图的处理和地理配准工作带来很大困难。本文将古地图的定位基准现状,分为完全没有地理参考、有部分地理参考和有较精确地理参考进行分析,从资料选取、预处理、辐射校正和图面信息复原角度探讨古地图的修复方法,并以部分近代地图为例进行地图拼接实验。最后,针对不同定位基准类型的古地图,分别采用特征点校正、分块(网格)匹配和相对位置转移等方法,完成古地图与现代地图的地理匹配,研究了计里画方地图与不同地理参考系、投影之间的数理关系。在古地图数字化、编辑、纠正和配准的基础上,尝试研究和建立校正后的古地图和现代地图的数理关系,探究古代舆图坐标基准和坐标体系与现代地图系统的关系,为建立古今坐标体系对照的数理关系打下基础。
The kilometer grid style and landscape painting style are two features of Chinese ancient maps. However, the positioning accuracy of ancient maps is very low due to the lack of a clear mathematical basis. It is difficult to apply map processing, map correction and geo-referencing on these ancient maps. This paper divides the current positioning datum of ancient maps into three types: one with no geo- reference, one with partial geo- reference, and one with definite geo- reference, and explores the map repairing methods from the following aspects: data selection, pre-processing, radiometric correction, and geographical information recovery. Besides, this paper takes some Chinese near modern maps as examples in several map matching experiments, adapts different spatial positioning methods, such as feature point correction, matching by grid, and relative position shift, to complete corrections between Chinese ancient maps and modern maps, and focuses on the mathematical relationship in the square grid maps and different geo-reference systems and projection systems. Finally, we try to establish the mathematical relationships between the corrected ancient maps and the accurate maps, and study the relationship between"six key points of mapping"and the modern coordinates system.