An empirical study of the limitations of Minimum Bounding Boxes for defining the extent of geospatial resources: the use of DGGS and other alternatives for improving the performance of spatial searches

<pre>A Minimum Bounding Box (MBB) is a rectangle which bounds a geographic feature or dataset. It is commonly used in spatial information systems as a simplified way of describing the spatial extent of a resource. MBBs are typically indexed for searching and discovering resources relevant to a given geographic area of interest. However, this simplification leads to a loss of precision in the description of the extent and can affect the overall precision of the search results.<br><br>We propose an alternative technique for describing the spatial extent based on the use of DGGS tiles. To measure the precision improvements offered by our method, we designed and implemented an empirical method for evaluating the average precision, and applied it to three different systems: one based on MBB, another on Convex Hull, and ours based on DGGS.The three methods were evaluated with the same test collection obtained from some of the main European geospatial data catalogues from the INSPIRE directive.<br>The results showed that our method outperformed the other two.Where the catalogue average precision of the MBB search scenarios is between 73% and 97%, the DGGS is between 96% and 99%. Additionally, we propose a realistic method of transitioning from the current technologies to the technology we are proposing, considering the current state of the spatial data infrastructures.</pre>

最小外接矩形（Minimum Bounding Box, MBB）是用于框定地理要素或数据集的矩形区域。在空间信息系统中，其常被用作简化描述资源空间范围的方式。MBB通常会被建立索引，以检索和发现与给定感兴趣地理区域相关的资源。然而，这种简化会导致空间范围描述的精度损失，进而可能影响搜索结果的整体精度。

我们提出了一种基于离散全球格网系统（Discrete Global Grid System, DGGS）瓦片的空间范围描述替代技术。为衡量本方法带来的精度提升，我们设计并实现了一种用于评估平均精度的实证方法，并将其应用于三类不同的系统：一类基于MBB，一类基于凸包（Convex Hull），以及我们基于DGGS的方法。

三类方法均使用从《INSPIRE指令》框架下的若干欧洲主流地理空间数据目录中获取的同一测试集开展评估。

实验结果显示，我们的方法性能优于另外两种方法。在MBB搜索场景中，对应目录的平均精度处于73%至97%区间，而DGGS方法的平均精度则处于96%至99%区间。此外，结合当前空间数据基础设施的发展现状，我们还提出了一种从现有技术过渡至所提技术的切实可行方案。