Team explores effect of space weather on communications

The first experiment to investigate the effects of plasmasphere disturbances on satellite communications will be launched aboard the UK Space Agency’s maiden CubeSat mission.

A team from Bath University’s Department for Electronic and Electrical Engineering has won one of four places on the 4.5kg UKube-1, which hopes to launch in January 2012.

Bath’s TOPCAT project will be one of the most comprehensive investigations into the effects of space weather on communications and will look at both the ionosphere and the less well-studied plasmasphere, which is at a higher altitude.

In recent years there has been increasing awareness about the effect of so-called space weather, which encompasses a range of solar phenomenon, including X-rays, electromagnetic radiation, radiowave bursts, and proton ejections.

These are generally mitigated well before they reach Earth, but because the activity of the sun waxes and wanes according to an 11-year cycle, bursts of energy can knock out GPS satellites and leave reliant systems vulnerable.

‘As the radiation comes off the sun it hits the Earth’s magnetosphere, which is the wider part of the plasmasphere, and it gets dragged in towards the ionosphere — that’s where it has the biggest effects. But actually knowing how the mechanism works, and how [radiation] moves from the plasmasphere to the ionosphere will be really helpful,’ said Bath researcher Dr Julian Rose.

The team’s device will be based on a specially modified dual-frequency GPS receiver, which will communicate with other satellites to build up an image of the plasmasphere and ionosphere based on the speed of transmissions.

‘We gather the data then image the level of electron activity — we’ll show bright red colours where there are a lot of electrons, so if you try to receive GPS around this area then the signal will be affected by so many metres, for example. Then it fades to yellow, green, and then blue, which would be an area where there are no problems,’ said Rose. 

Although the TOPCAT project essentially represents a feasibility study, Rose envisages a fleet of satellites trained on the outer plasmasphere, which could give advanced warning of disturbances.

The other projects on board UKube-1 include a camera that will take images of the Earth using a new generation of imaging sensor; an experiment to demonstrate the feasibility of using cosmic radiation to improve the security of communications satellites; and a payload made up of five experiments that UK students and the public can interact with.

With major constraints in terms of power, space and data storage, the team will use the next six months to streamline its device before it undergoes testing.

TOPCAT is funded by Bath University and the Bath Alumni Fund. It is supported by Rutherford Appleton Laboratory, Mullard Space Science Laboratory and UK company Chronos Technology.