针对单一描述语句表达位置信息的不足,如依赖用户对单一参照物的熟悉程度、定位范围较大而不明确等,本文提出同时采用多种参照物并兼顾多种空间关系的组合描述机制,逐步逼近目标位置,同时弱化用户对参照物的认知依赖。探讨了具有结构特征及与目标物有空间关系约束等不同类型参照物的选取方法,研究了空间关系等相对位置信息的描述参数及其计算方法,并结合空间认知理论将结果转换为对应的自然语言词汇,通过各种类型信息自然语言描述语句的句法模式形成完整的语句,最后在组合描述原则的指导下,将多个描述语句整合为多空间认知层次、多定位结构的位置信息描述语段。经实验对比单句描述与组合描述两种方式,证明后者有助于提高地理目标位置认知与定位的效果。

Geographic location which can generally be described either absolutely or relatively is the locating information of a spatial object in geographic environment. Absolute method takes use of words or numbers that uniquely identifies the location of spatial entities, such as latitude and longitude coordinates, address, etc. by establishing a unified coding system. On the contrary, relative method locates a target object by the spatial relation between the target and its reference, which is coincident with people's spatial recognition habit and follows the development trend of socialization GIS service through combination with natural language. However, single sentence describing target location can cause such deficiencies as reliance on the very reference object and large uncertain locating area. This paper proposed a combinative description method to combine single description sentences of different reference objects and different spatial relations into one paragraph to approach the target location and diminish the reliance on the single reference object. Reference objects were cataloged to different types according to their characteristics: distinctive geographic semantics, a particular structure, and spatial relation constraints with the target object. Means of choosing various reference objects were discussed, and parameters of location information according to various reference objects such as spatial relations (including topological relation, direction relation and distance relation) as well as polylines' strike and polygons' extent were listed out, computed and transformed into corresponding words which were then filled into a sentence within the syntactic pattern. Under the principle of combination, single sentences were grouped into a comprehensive paragraph. The description experiment comparing single description sentence and combination paragraph showed that this approach attained various spatial recognition level and locating structure, and was preferable to better understand and locate a geographic location.