1. Department of PhysicsUniversity of Oulu Oulu Finland
2. Sodankylä Geophysical ObservatoryUniversity of Oulu Sodankylä Finland
3. STFC Rutherford Appleton LaboratoryHarwell Science and Innovation Campus Didcot UK
4. MIT Haystack Observatory Westford Massachusetts USA
5. ASTRON Dwingeloo Netherlands