Early Warnings and Alerts

Several satellite observations, mainly made in the optical part of the electromagnetic spectrum and with different spatial/temporal resolutions, have proved to be useful for providing early indications or rapid alerts about events (e.g. conflict, unrest) that might pose a risk not only to civilian populations but also to regional security. In particular, meteorological satellites, which have a low spatial resolution but a high (up to 6 hours for NOAA-AVHRR) or very high (up to 15 minutes for MSG-SEVIRI) time repetition rate, have shown new potentials in the field of security-related applications as soon as suitable algorithms (like the Robust Satellite Technique - RST) are applied to the observations they provide in the optical range. RST demonstrated indeed both robustness (minimizing the proliferation of false alarms) and sensitivity (detecting even low intensity changes of the observed signal) in the identification of thermal anomalies related to potentially dangerous events. In the context of early warnings, the detection capabilities of SEVIRI channels were successfully tested, for example, in the case of numerous terrorist attacks to Iraqi pipelines and to other, rapidly evolving phenomena, related to security issues, such as terrorist bombings of buildings or oil spills caused by pipeline sabotages. The timely detection of such thermal anomalies may be used to give an early/ rapid warning of possible accidents, providing a support to the decision-makers. Integration with observations at a medium (Landsat) or high (Quickbird) spatial resolution (when achievable) could surely help in order to better define the exact nature of events timely detected (but not very precisely located) by meteorological