TY - JOUR T1 - GNSS Transpolar Earth Reflectometry exploriNg System (G-TERN): Mission Concept A1 - Cardellach,Estel A1 - Wickert,Jens A1 - Baggen,Rens A1 - Benito,Javier A1 - Camps,Adriano A1 - Catarino,Nuno A1 - Chapron,Bertrand A1 - Dielacher,Andreas A1 - Fabra,Fran A1 - Flato,Greg A1 - Fragner,Heinrich A1 - Gabarro,Carolina A1 - Gommenginger,Christine A1 - Haas,Christian A1 - Healy,Sean A1 - Hernandez-Pajares,Manuel A1 - Hoeg,Per A1 - Jaggi,Adrian A1 - Kainulainen,Juha A1 - Khan,Shfaqat Abbas A1 - Lemke,Norbert M. K. A1 - Li,Weiqiang A1 - Nghiem,Son V. A1 - Pierdicca,Nazzareno A1 - Portabella,Marcos A1 - Rautiainen,Kimmo A1 - Rius,Antonio A1 - Sasgen,Ingo A1 - Semmling,Maximilian A1 - Shum,C. K. A1 - Soulat,Francois A1 - Steiner,Andrea K. A1 - Tailhades,Sebastien A1 - Thomas,Maik A1 - Vilaseca,Roger A1 - Zuffada,Cinzia AD - CSIC, Inst Space Sci, Cerdanyola Del Valles 08193, Spain. AD - GFZ German Res Ctr Geosci, D-14473 Potsdam, Germany. AD - IMST GmbH, D-47475 Kamp Lintfort, Germany. AD - Airbus DS Space Syst Espana, Madrid 28022, Spain. AD - UPC, IEEC, Barcelona 08034, Spain. AD - DEIMOS Engn, P-1998023 Lisbon, Portugal. AD - IFREMER, F-29280 Plouzane, France. AD - RUAG Space GmbH, A-1120 Vienna, Austria. AD - Environm & Climate Change Canada, Victoria, BC V8P 5C2, Canada. AD - Inst Ciencies Mar, Barcelona 08003, Spain. AD - Barcelona Expert Ctr Remote Sensing, Barcelona 08003, Spain. AD - Natl Oceanog Ctr, Southampton SO14 3ZH, Hants, England. AD - Alfred Wegener Inst Polar & Marine Res, D-27570 Bremerhaven, Germany. AD - ECMWF, Reading RG2 9AX, Berks, England. AD - Univ Oslo, Dept Phys, N-0371 Oslo, Norway. AD - Univ Bern, Astron Inst, CH-3012 Bern, Switzerland. AD - Harp Technol Oy, Espoo 02150, Finland. AD - Tech Univ Denmark, Natl Space Inst, DK-2800 Lyngby, Denmark. AD - OHB Syst AG, D-82234 Weling Oberpfaffenhofen, Germany. AD - CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. AD - Univ Roma La Sapienza, Dept Informat Elect & Commun Engn, I-00185 Rome, Italy. AD - Finnish Meteorol Inst, Helsinki 101, Finland. AD - Ohio State Univ, Columbus, OH 43210 USA. AD - Collecte Localisat Satellites SA, F-31520 Ramonville St Agne, France. AD - Karl Franzens Univ Graz, Wegener Ctr Climate & Global Change, A-8010 Graz, Austria. AD - TRYO Grp, La Garriga 08530, Spain. UR - https://archimer.ifremer.fr/doc/00438/54994/ DO - 10.1109/ACCESS.2018.2814072 KW - Polar science KW - GNSS KW - reflectometry KW - GNSS-R KW - sea ice KW - altimetry KW - polarimetry KW - radio-occultation KW - Low Earth Orbiter N2 - The global navigation satellite system (GNSS) Transpolar Earth Reflectometry exploriNg system (G-TERN) was proposed in response to ESA's Earth Explorer 9 revised call by a team of 33 multi-disciplinary scientists. The primary objective of the mission is to quantify at high spatio-temporal resolution crucial characteristics, processes and interactions between sea ice, and other Earth system components in order to advance the understanding and prediction of climate change and its impacts on the environment and society. The objective is articulated through three key questions. 1) In a rapidly changing Arctic regime and under the resilient Antarctic sea ice trend, how will highly dynamic forcings and couplings between the various components of the ocean, atmosphere, and cryosphere modify or influence the processes governing the characteristics of the sea ice cover (ice production, growth, deformation, and melt)? 2) What are the impacts of extreme events and feedback mechanisms on sea ice evolution? 3) What are the effects of the cryosphere behaviors, either rapidly changing or resiliently stable, on the global oceanic and atmospheric circulation and mid-latitude extreme events? To contribute answering these questions, G-TERN will measure key parameters of the sea ice, the oceans, and the atmosphere with frequent and dense coverage over polar areas, becoming a "dynamic mapper" of the ice conditions, the ice production, and the loss in multiple time and space scales, and surrounding environment. Over polar areas, the G-DERN will measure sea ice surface elevation (<10 cm precision), roughness, and polarimetry aspects at 30-km resolution and 3-days full coverage. G-TERN will implement the interferometric GNSS reflectometry concept, from a single satellite in near-polar orbit with capability for 12 simultaneous observations. Unlike currently orbiting GNSS reflectometry missions, the G-TERN uses the full GNSS available bandwidth to improve its ranging measurements. The lifetime would be 2025-2030 or optimally 2025-2035, covering key stages of the transition toward a nearly ice-free Arctic Ocean in summer. This paper describes the mission objectives, it reviews its measurement techniques, summarizes the suggested implementation, and finally, it estimates the expected performance. Y1 - 2018 PB - Ieee-inst Electrical Electronics Engineers Inc JF - Ieee Access SN - 2169-3536 VL - 6 SP - 13980 EP - 14018 ID - 54994 ER -