Reading the signals

Surrey Satellite Technology Limited (

) will lead a British project to exploit signals from GPS and GNSS navigation satellites that are reflected from the Earth for remote-sensing purposes.

The project will investigate a prototype instrument capable of measuring the roughness of the sea and soil moisture content, which will provide data for atmospheric science and for operational ocean and weather forecasting.

SSTL will lead a team of experts from the National Oceanographic Centre in Southampton and the universities of Bath and Surrey to further technological capability in line with UK Earth observation science priorities.

Funding for the project has been made available by the Centre for Earth Observation Instrumentation (CEOI), the Natural Environment Research Council (NERC) and the Department for Innovation, Universities & Skills (DIUS).

According to SSTL, signals from GPS and GNSS navigation satellites reflected from land, ice and ocean will be analysed by the instrument, which will fly on board a separate small satellite.

A flexible multi-channel receiver will be developed to detect the reflected GNSS signals for surface sea-state measurements.

Using the remote-sensing technique, it is possible to derive scientific data about the nature of the reflecting surface and the atmosphere, such as the sea-surface roughness or soil moisture content.

Sea-surface roughness is important for operational ocean and weather forecasting and affects many areas of ocean and atmospheric science.

The air-sea exchange of gases is controlled by surface roughness. Evidence suggests that the better sampling offered by a new instrument will have a direct impact on understanding the magnitude and distribution of atmospheric CO₂ uptake by the ocean, with important applications in the prediction of high winds, dangerous sea states, risk of flooding and storm surges.

Opportunities to fly this instrument have been identified both through SSTL's satellite launching capability and the European Space Agency (

) as an approved addition to a future Soil Moisture and Ocean Salinity operational mission (SMOS-ops).