1. Geodesy Research Laboratory National Institute of Cartography Yaoundé Cameroon
2. Department of Physics University of Yaoundé 1 Yaoundé Cameroon
3. Faculty of Physics, Department of Geophysics University of Science, Vietnam National University Thanh Xuan Vietnam
4. Lantmäteriet Gävle Sweden
5. Centro de Pós Graduação em Geofísica (CPGF) Universidade Federal do Pará (UFPA) Belém Brazil
6. Department of Land Surveying and Geo‐Informatics Hong Kong Polytechnic University Hung Hom Hong Kong