1. Mullard Space Science Laboratory; University College London; Dorking UK
2. Space Science and Technology Department; Rutherford Appleton Laboratory; Didcot UK
3. Department of Communication Systems; Lancaster University; Lancaster UK
4. Research and Scientific Support Department; European Space Agency; Noordwijk Netherlands
5. Centre d'Etude Spatiale des Rayonnements; Centre National de la Recherche Scientifique; Toulouse France
6. Space and Atmospheric Physics, Blackett Laboratory; Imperial College London; London UK