GEROS (GNSS REflectometry, radio occultation, and scatterometry onboard the International Space Station) is an innovative ISS experiment primarily focused on exploiting reflected signals of opportunity from the GNSS satellites at L-band to measure key parameters of ocean surfaces which are relevant to characterise climate change. Secondary mission goals are global atmosphere and ionosphere observations using the GNSS radio occultation technique and the monitoring of land surface parameters utilizing reflected GNSS signals.

Image: Schematic overview of the GEROS experiment to be installed aboard the International Space Station. Red lines indicate the reflectometry measurements for water, ice and land surface monitoring. Blue lines indicate GNSS RO and coherent reflectometry observations and the green lines symbolize the GNSS signals, received from zenith for Precise Orbit Determination (POD) of the GEROS payload and 3D upside ionosphere monitoring. Credit: GFZ.

Complementing the Earth system observations from other current satellite missions, GEROS will especially pioneer the exploitation of GNSS remote sensing signals from the European Galileo system, thereby improving the accuracy as well as the spatio-temporal resolution of the derived geophysical properties compared to GPS only measurements. The additional use of signals from the Russian GLONASS, Chinese Beidou and Japanese QZSS navigation satellite systems is also a goal.

GEROS will contribute to the long-term and climate relevant observation of the major components of the Earth System: Oceans/Hydrosphere, Cryosphere/Snow, Atmosphere/Ionosphere and solid Earth/Landcover with innovative and complementary aspects compared to established Earth Observation satellite missions.

IEEC’s contribution

The IEEC, though the Institute of Space Sciences (ICE, CSIC), is part of the proposing team. It has a representative co-chairing the interdisciplinary and international Science Advisory Group (SAG) of acknowledged experts in Oceanography, Geodesy, Atmosphere and GNSS Science, a group funded and nominated by ESA.

The IEEC (IEEC-UPC and IEEC-CSIC) also participated in an industrial feasibility study (Phase-A study), as well as the first scientific contract to assess the performance of the mission's main concepts (GARCA project). The ICE (IEEC-CSIC) has developed the Software PARIS Interferometric Receiver (SPIR) under an ESA contract, to test the synoptic capabilities of the altimetric technique to be implemented at the GEROS-ISS.

Image: The SPIR instrument (top-left) developed at ICE (IEEC-CSIC) to check the synoptic capabilities of the interferometric GNSS technique for altimetric applications. The receiver has been tested in several flights aboard the Skyvan aircraft (Aalto University).

More information on the ESA website
More information on the NASA website
More information on the GFZ website

Generalitat de CatalunyaUniversitat de BarcelonaUniversitat Autònoma de BarcelonaUniversitat Politècnica de CatalunyaConsejo Superior de Investigaciones CientíficasCentres de Recerca de Catalunya