空间数据连续尺度表达的矢量金字塔模型

A Vector Pyramid Model to Support Continuous Multi-scale Representation of Spatial Data

连续多尺度表达是当前地图制图领域中的热点问题之一,常规地图采用多级瓦片剖分、多版本存储技术实现空间多尺度表达,存在数据量冗余、跨级别不一致、瓦片间尺度跳跃大等问题。结合传统地图综合、多尺度表达数据结构和空间索引建立等多种策略,在目标数据模型中加入尺度维和操作信息,记录地图综合的过程和尺度变换,建立空间数据矢量金字塔模型。该模型离线综合获取多级基态尺度表达数据,确定每个目标的尺度表达空间范围,并通过面向对象建模技术将目标表达状态及其纵向关联关系、算子类型及控制参量等信息封装在多尺度目标中;同时,建立一端或两端控制的尺度变换结构。基于该模型可快速获取适应用户需求的连续尺度表达状态。

The continuous multi-scale representation is one of attractive problems in mapping technology.Conventional mapping which uses the subdivision of multilevel tiles or multi-version storage to accomplish spatial multi-scale representations has the problems including data redundancy,inconsistency between diffident levels,the dramatic change in scale range and others.This study comprehensively applies various multi-scale representation strategies,including the cartography generalization and the spatial index technology,and put scale dimension and operations information in data model to build The Vector Spatial Data Pyramid Model.This model builds up key scale representations data and controls the scales space of every target through the off-line processing.And the process information,including the representation status of object,the longitudinal association between object Aand object B in diffident levels,the generalize operators and parameters,is encapsulated in the attributes of objects through object-oriented modeling.Meanwhile,this model establishes scale transformation structure through one end and both end of the control.Based on the pyramid model,the generalization action can be executed in real-time to obtain continuous scale representation.