We address the problem of registering and discovering sensors, sensor services and other related resources in the Semantic Sensor Web. We show how to develop a semantic registry for the storage and manipulation of metadata describing such resources using an implementation of the data model stRDF and the query language stSPARQL. stRDF extends RDF with the ability to represent spatial and temporal metadata using linear constraints. stSPARQL extends SPARQL for querying stRDF metadata. Together they provide a natural modeling framework for the problem at hand, since spatial and temporal metadata figure prominently in the description of sensors and related resources or services. We present Strabon, a storage and query evaluation module for stRDF/stSPARQL for the architecture of the EU FP7 project SemsorGrid4Env and we show how to use Strabon to implement a semantic registry.