Surrey Blog

SGR-ReSI Instrument Measures Maritime Winds and Waves

May lead to better weather forecasts...

We are excited about the early results from an instrument flying onboard our TechDemoSat-1 satellite, launched earlier this year. This instrument is the Space GNSS Receiver Remote Sensing Instrument (SGR-ReSI) developed by our GNSS experts, led by Dr. Martin Unwin, principal engineer at SSTL in the United Kingdom.

We designed the SGR-ReSI to collect the signals from GPS and other navigation satellites after they have reflected off the ocean surface. The instrument generates images called delay Doppler maps, which are used to interpret ocean roughness and wind speed measurements of the sea surface.

The technique works in a similar way to existing scatterometer technology; however, it eliminates the need for a transmitter and can process multiple reflections from different GPS satellites simultaneously, presenting an opportunity for collecting data more frequently, and over a greater area at a lower cost.

“This is a complementary technology to the well-proven space-based scatterometers,” said Dr. Unwin. “GNSS reflectometry uses a longer wavelength and measures the slope of the swell at the sea surface. It only needs a relatively small, low-power, and low-cost modified GPS receiver so it’s a practical payload that can be flown on multiple satellites. Measurements from many satellites will increase the available temporal and spatial resolution over today’s state of the art, and in future could lead to better global weather forecasting.”

How does it work?

The map below shows the SGR-ReSI targeting four potential reflected signals from GPS satellites around the Bay of Alaska.

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03 November 20140 Comments0 Comments

How a Small Wheel Helped to Stabilize Philae's Bumpy Landing

The genesis of Philae's momentum wheel and the emotions of comet-landing day in the words of a Surrey Satellite Technology engineer who worked on the project.

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18 November 20140 Comments0 Comments