1. Physical Sciences Division, National Environmental Research Council; British Antarctic Survey; Cambridge U.K.
2. Department of Physics; University of Otago; Dunedin New Zealand
3. Dunedin New Zealand
4. Space Plasma Environment and Radio Science Group, Department of Communication Systems; Lancaster University; Lancaster U.K.
5. Earth Observation; Finnish Meteorological Institute; Helsinki Finland
6. Los Alamos National Laboratory; Los Alamos New Mexico USA
7. School of Mathematical and Physical Sciences and Cooperative Research Centre for Satellite Systems; University of Newcastle; Callaghan, New South Wales Australia