ESA HydroGNSS Scout – A Small Satellite Mission Sensing Climate Variables using GNSS Reflectometry

How satellite navigation signal reflections can be used to help monitor the water cycle of the planet.

  • Mon 13th Nov 2023

SSTL, part of the Airbus group, is a UK spin-off company from the University of Surrey that designs, manufactures and operates small satellites. Amongst its activities, it builds optical, thermal and radar imaging satellites, and is currently manufacturing the Lunar Pathfinder mission to offer communications links for lunar assets. Another SSTL project is the ESA HydroGNSS Scout mission comprising two small satellites that will measure climate variables using satellite navigation signal reflections. GNSS microwave signals are continually being broadcast towards the Earth from over 100 satellites in high orbits, and are used for all kinds of navigation, including military, marine, aircraft, automotive and mobile phone. Although these signals are very weak, they reflect off the Earth’s surface and can be detected by spacecraft in low Earth orbit and used as radar sources for sensing geophysical properties of the Earth. HydroGNSS plans to process these reflections to measure soil moisture, inundation, freeze/thaw, and biomass, with secondary measurements of ocean wind speed and sea ice extent, all parameters important for the monitoring and understanding of our changing climate.

Dr Martin Unwin, Surrey Satellite Technology Ltd

Martin Unwin studied his PhD from the University of Surrey, completing in 1995 during which time he participated with Surrey Satellite Technology Ltd (SSTL) in the first use of a GPS receiver on a small satellite, PoSat-1. As an employee of SSTL he then continued with the design of GPS and GNSS receivers for spacecraft, developing products used on many satellites, and exploring different applications including attitude determination, high altitude GNSS, and remote sensing. Dr Unwin is now the Industrial Principal Investigator for the ESA HydroGNSS Scout mission. He is a Fellow of the Royal Institute of Navigation, holds the 2011 ION Tycho Brahe award, and the 2017 RAeS Silver Medal.

Attending lectures

Full video

The lecture will be preceded by a short presentation from a CSAR PhD Award Winner.

Using AI, medical records and fruit flies to gain insights into Alzheimer's disease.

Yizhou Yu, MRC Toxicology Unit, University of Cambridge.

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