基于混合瓦片的海量DEM/DOM数据高效存储管理方法——以应急救灾数据库为例

Efficient Storage Management of Massive DEM/DOM Data Based on Mixed Tile Range: A Case Study of Emergency Relief Database

针对传统DEM/DOM数据存储管理采用同一瓦片剖分导致大量DEM小文件入库效率极低的问题,在传统地形金字塔的数学基础上,建立DEM/DOM混合瓦片的金字塔模型。该模型考虑相同空间范围内DEM瓦片文件远小于DOM瓦片文件大小的数据特点,通过为DEM和DOM划分不同的瓦片范围,平衡瓦片文件大小;将空间相关的DEM瓦片打包,以减少文件数量,提高入库效率;设计了瓦片ID的编码方式,隐式存储非均衡瓦片范围的DEM瓦片和DOM瓦片的映射关系,支持无缝调度和浏览。以分布式数据库MongoDB为平台进行实验,验证了本文方法的可行性和有效性。

The traditional method of managing DEM/DOM is based on partitioning terrain tiles using the same tile range, which results in inefficient storage of the large number of small DEM files. This paper builds a mixed DEM/DOM tile pyramid on the mathematical basis of traditional terrain pyramid. The new pyramid considers the data characteristics that DEM tile size is much smaller than the DOM tile size. By dividing DEM/DOM tile with different tile ranges, packaging space-related small files into a bigger one, the new pyramid effectively balances the DEM/DOM tile sizes and reduces the DEM files number, which greatly improves the storage efficiency. This paper offers a new method which designs a new tile ID structure to implicitly store the mapping relationship of non-equilibrium DEM/DOM tiles. Finally, the validity and feasibility of this method are proved through the experiment in the platform of distributed database MongoDB.