Since the launch of Sputnik in 1957, the skies above us have gradually filled with artificial satellites. Monitoring, communicating and observing. From predicting the weather forecast to looking out into deep space, we've come to rely on the information this network can provide us with. Perhaps of all the satellite systems, we depend most on the Global Positioning System (GPS), a radio navigation system that helps us locate, track and navigate.
GPS technology is used across our society and economy in transport, farming and law enforcement, and underpins banking transfers, digital maps and mobile phones. Any disturbance to this service would result in major disruption to our daily lives, and this has left us increasingly vulnerable to both natural space weather events and criminal activities.
Danger from solar flares
Storms on the surface of the sun can bombard the Earth with powerful radiation causing satellite signal loss and fading. Many of our satellites orbit in an area of our upper atmosphere known as the ionosphere, about 80km above the Earth's surface.
From the Arctic to Antarctica, we have gathered data using a network of GPS scintillation receivers and combine this with other information using algorithms that carry out complex signal-processing tasks, tomography and data assimilation.
This suite of mathematical algorithms, researched, designed and developed at Bath, is called Multi-Instrument Data Analysis System (MIDAS). MIDAS is the culmination of over 20 years of our space-based communication research and is used under licence by many other academic institutions across the globe.
Using MIDAS we are able to reconstruct highly-accurate three-dimensional images of the Earth's ionosphere. MIDAS works in real-time, so it can continuously monitor and determine the changing nature of the ionosphere as it responds to space weather. It then uses this information to calculate the exact effect of this weather on position errors in GPS measurements to improve their accuracy.