GNSS-Reflectometry (GNSS-R) Data

Muon Space's GNSS-Reflectometry (GNSS-R) Data measures near-surface soil moisture and ocean surface wind speed from navigation-satellite signals reflected off the Earth's surface. It serves weather agencies and Earth-science users who need near-surface soil moisture over land and wind speed over the ocean; Muon's measurements build on the legacy of NASA's CYGNSS GNSS-R mission.

Muon's Signals of Opportunity (SoOpr) instrument flies on Muon-built satellites in sun-synchronous orbit. Nadir-facing antennas receive GPS signals (and, on MuSat2, Galileo signals) reflected from the surface, a passive bistatic radar measurement. The data are processed into three levels: L1 calibrated delay Doppler maps with reflectivity, bistatic radar cross section and specular-point geometry; L2 track-wise and daily retrievals of soil moisture and ocean wind speed; and L3 gridded products at hourly and daily intervals. Products are delivered to the customer's cloud environment.

MuSat2 and MuSat3 collect dual-polarised (LHCP/RHCP) reflections, which may help correct surface-roughness effects in soil moisture retrievals. MuSat4 (the FireSat protoflight) and the three operational FireSat satellites carry 20 dBi antennas, higher gain than earlier GNSS-R missions, intended to reduce error in high wind-speed retrievals and improve soil moisture estimates under dense vegetation. Muon supplied GNSS-R soil moisture and ocean wind products to the US Air Force under its Commercial Weather Data Pilot. NASA's Commercial Satellite Data Acquisition (CSDA) programme has acquired Muon's GNSS-R datasets, and in September 2025 NOAA awarded Muon a $1,998,000 GNSS-R ocean surface winds data pilot.