Concept study about new ground-based and space-borne HF and microwave systems for Tsunami detection - Concept Study Report 2006

The WP’s 4430 and 4440 investigate the requirements of possible ground based and space borne radar systems as required for a continuous observation over a large ocean area. In these studies the basic geophysical tsunami parameters which are accessible for radar remote sensing systems are summarised and a couple of system concepts with potential for tsunami monitoring are discussed. As far as ground based tsunami detection is concerned, the interaction of a High Frequency field HF (3–30 MHz) with ocean waves was of particular interest and therefore reviewed in details. The use of a ground based system is restricted in its range so that in view of a surveillance of the entire Indian Ocean, space borne radars are a cost-efficient solution and a robust monitoring method independent of sunlight and weather conditions. Hence, they are envisioned as a candidate to provide continuous observations of large areas as required by any early warning system. The requirements of both systems are presented and analyzed in the following. The studies are subdivided as follows: At the beginning the general physics of a tsunami is presented and the geophysical observables for an incident electromagnetic HF and microwave field are discussed. Thereon, the concept of a ground based system is introduced at the beginning. Afterwards the concept for an observation platform in space is figured out and the theoretical and technical limits are investigated. Finally, the modelling of a realistic ocean surface is introduced and the further steps for calculating the diffracted field from an illuminated ocean patch are reviewed.