PRETTY CubeSat with two patch antennas

Our planet is being continuously bathed in radio signals from satnav satellites – which are useful for much more than just navigation. Dedicated space missions acquire these signal reflections to amass valuable environmental information. The shoebox-sized PRETTY CubeSat, flying on Europe’s next Vega launcher, will investigate a new frequency and novel observation angle to better measure the rate of climate change – at the same time as gathering radiation data on its surrounding space environment. 

The two patch antennas seen here on its forward face will pick up the same signal from the same satellite – or rather one signal that has reached it through space and the equivalent signal that has reflected off Earth’s cryosphere or oceans. Using a highly advanced version of ‘spot the difference’ PRETTY will compare the twin signals onboard to derive ice and sea height to an accuracy of at least 50 cm from 550 km orbital altitude.