应用于GIS系统的多级时序数据模型

GIS中地理对象生命期的表示以及动态信息的表达需要时序数据的支持。一些基于关系数据库的GIS系统在实现时序数据时形成大量的数据冗余且难以维护数据的一致性。针对这些问题，结合GIS中对于时序精度的不同需求，提出了一种多级别时序数据模型。讨论了时间的相关概念，定义了一套基本的时间对象类型，提出并解释了对象级和属性级时序数据模型。基于面向对象数据库的实现显示，模型不仅满足了GIS中支持时序数据的需求，同时在存储开销、数据一致性等方面具有显著的优点。

Multi-level temporal data model in GIS

There is an increasingly requirement for dynamic geographic data representation, such as the lifecycle of geographic features.Temporal data management thus becomes an urgent necessity. When temporal data management being supported, systems based on relational databases usually suffered problems from massive redundant data and data inconsistency. A multi-level approach was presented that solved these problems as well as the request for different temporal data scales. First, the common issues on timing models were introduced and the basic time-obj ect architecture was defined. Then a temporal data model was built with different data scales and levels,An instance based on an object-oriented database demonstrates that this model is fully sufficient with temporal data management, which has considerable advantage on storage saving and data consistency.