GNSS transpolar earth reflectometry exploriNg system (G-TERN): Mission concept

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-TERN 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

IEEE 4003-2021

27 páginasThe scope of this effort is to develop a standard for data and metadata content arising from spaceborne global navigation satellite system-reflectometry (GNSS-R) missions, which uses GNSS signals as signals of opportunity, as described in “The IEEE SA Working Group on Spaceborne GNSS-R: Scene Study.” In particular, this standard would provide a means for describing: a) The terminology assigned to GNSS-R data and products, such as the product levels. b) The structure and content of the data. This includes, but is not limited to, units of measure, data organization, data description, data encoding, and data storage format. c) The metadata. This includes and is not limited to metadata, methods and algorithms applied to the data, parameters related to the algorithms, citation information, instrument calibration and characterization, and description of the input signals. The purpose of this standard is to provide a set of specifications and recommended practices that can be used to describe any known and future spaceborne GNSS-R data set, allowing users to work with different GNSS-R data sets at the same time. The definition of such standard would also allow any software that uses these data to fully operate and ingest any spaceborne GNSS-R input data as they will conform to the same standard

First Field-Test results of iGNSS-R instrument of the PRETTY payload

Talk delivered in EGU General Assembly online, 4-8 May 2020The PRETTY mission is a 3U CubeSat mission, hosting two different payloads, a radiation dosimeter and an interferometric GNSS reflectometer. The intended launch is planned in 2022

STATUS OF THE ESA PRETTY MISSION

Talk delivered in IEEE International Geoscience and Remote Sensing Symposium online, 26 September 2020 - 02 October 2020Invited Sessions: Advances in Reflectometry with GNSS and Signals of Opportunity (GNSS+R

THE GRSS STANDARD FOR GNSS-REFLECTOMETRY

Talk delivered in 2020 IEEE International Geoscience and Remote Sensing Symposium online, 26 September - 2 October, 202