Nowadays, the geographic metadata are defined by the ISO standards and they have in particular the aim of assisting data exchange between different users and also to provide data quality information. However, these metadata are defined for static data processed in traditional applications. Such metadata do not take into consideration the qualification of dynamic data resulting from sensors, like the real-time measurements managed in “on-line” applications. Moreover, sensor networks linked to databases are more and more used in many fields like environmental and industrial monitoring. The real-time management of spatiotemporal data coming from sensors requires a definition of real-time metadata, especially for quality assessment in a decision support context during a critical situation.