A major motivation for the small satellite activities at GFZ was the extremely successful GPS radio occultation experiment aboard the CHAMP satellite [1]. Later, the application of GNSS-R within future generation Tsunami Early warning systems was investigate in more detail as part of the GITEWS project [2]. Based on these investigations in total three feasibility studies for the definition of small satellite projects with scientific GNSS payload were performed: MicroGEM [3], NanoGEM [4], and NanoX [5]. Additional objective of these missions is geodetic co-location using three different space geodetic techniques (GNSS. VLBI and SLR).
GFZ is recently involved in small satellite project for GNSS-Reflectometry of the RUAG company in cooperation with the European Space Agency ESA (PRETTY, [6]). The satellite was successfully launched October 9, 2023 from Kourou (French-Guayana).
References
[1] Wickert, J.; Reigber, C.; Beyerle, G.; König, R.; Schmidt, T.; Grunwaldt, L.; Galas, R.; Meehan, T.; Melbourne, W. G.; Hocke, K.: Atmosphere sounding by GPS radio occultation: First Results from CHAMP. Geophysical Research Letters, 28, 17, 3263-3266, 2001.
[2] Stosius, R.; Beyerle, G.; Hoechner, A.; Wickert, J.; Lauterjung, J.: The impact on tsunami detection from space using GNSS-reflectometry when combining GPS with GLONASS and Galileo on GNSS-Reflectometry tsunami detection from space. Advances in Space Research, 47, 5, 843-853, 2011.
[3] Briess, K., Kornemann, G., Wickert, J., MicroGEM: Microsatellites for GNSS Earth Monitoring, Abschlussbericht Phase 0/A, pp. 244, 2009.
[4] Wickert, J., Rothacher, M., Brieß, K., Wahnschaffe, G., Pilz, N., NanoGEM: Phase A, Schlußbericht, pp 144, 2011.
[5] Buhl, M., Segert, T., Wickert, J., Rothacher, M., Machbarkeitsuntersuchung Nano-X, Abschlussbericht Phase 0, pp. 121, GFZ-TN03, 2012.
[6] Cardellach, E., Li, W., Nahavandchi, H., Semmling, M., Moreno Bulla, M.A., Hoque, M. M.,Wickert, J., Asgarimehr, M., Zus, F., Dielacher, A., Hoermanseder, W., and Moser-Moritsch, M. (2024) Precise GNSS-R Altimetry with the ESA PRETTY CubeSat: Initial In-Orbit Results. 2024 IEEE International Geoscience and Remote Sensing Symposium, Athens, Greece, https://2024.ieeeigarss.org/view_paper.php?PaperNum=4749