Design of objectified spatial-temporal relation data model for WalkGIS platform

Abstract

This paper discusses the research and design of spatial-temporal relational model in WalkGIS platform, which complies to the OpenGIS standards. The paper falls under the context of National High-tech Supporting project 2 . The spatial-temporal relational model aims at spatial-temporal objects, and one spatial-temporal relation object corresponds to several tense instances, comparing to the traditional object relation model for one instance with several tenses. Object relation model is the special example of spatial-temporal model, which can be defined as single temporal model. Spatial-temporal relational model establishes and maintains constraints and relationship in spatial objects and temporal-serial instance relationship, performs the transformation of object-based discreet relationship (object-relation) to object-based spatial-temporal relationship (object-spatial temporal relation), creates and constraints temporal relation of instances in different times for one object and instance spatial relationship at different times. This article focuses on temporal model management and design for the objectified spatial-temporal model. Spatial-temporal model supports multi-user and multi-scene. Firstly, multi-user online editing. Each version can be edited independently. It checks interactively and coordinates version conflicts while editing and uploading. Secondly, stream model, multi-version creates the stream model. Thirdly, offline capabilities. Fourthly, version compression. Frequently altered versions can be combined into one version at the end of the year. Fifthly, version transfer. Any version can be transferred and stored into another spatial database. This paper covers spatial-temporal model definitions, model application scenario, model design constraints, version conflicts and reconciliation, data structure design, version management design, etc...