Despite the extensive work done in the scientific visualization community on
the creation and optimization of spatial data structures, there has been
little adaptation of these structures in visual analytics and information
visualization. In this work we present how we modify a space-partioning time
(SPT) tree -- a structure normally used in direct-volume rendering -- for
geospatial-temporal visualizations. We also present optimization techniques
to improve the traversal speed of our structure through locational codes and
bitwise comparisons. Finally, we present the results of an experiment that
quantitatively evaluates our modified SPT tree with and without our
optimizations. Our results indicate that retrieval was nearly three times
faster when using our optimizations, and are consistent across multiple
trials. Our finding could have implications for performance in using our
modified SPT tree in large-scale geospatial temporal visual analytics
software.