Semantic analysis and retrieval of spatial data based on the uncertain ontology model in Digital Earth

Metadata are the information about and description of data. In Digital Earth, metadata become variant and heterogeneous with many uncertainties. This paper studies uncertain features in the generation and application of metadata, and two types of uncertainties (incomplete and imprecise) are described based on semantic quantitative measurement method semantic relationship quantitative measurement based on possibilistic logic and probability statistic (SRQ-PP). Moreover, in the case study, we apply two types of quantitative measurements based on SRQ-PP to describe incomplete (uncertain) knowledge and imprecise (vague) information separately in spatial data service retrieval, which in turn is helpful to identify additional potential data resources and provide a quantitative analysis of the results.