Navigation Via Commercial LEO Satellites
The Global Positioning System (GPS) is a vital component of systems ranging from the power grid, to wireless communications and even landing aircraft. However, GPS does have its drawbacks: it is easy to jam and it is very expensive to both operate and maintain. The challenge is to both improve the resilience of GPS while decreasing the cost of this now essential infrastructure.
To solve this, we look towards the changing market of space. New players are coming with proposals to build constellations of hundreds and even thousands of satellites in low Earth orbit (LEO). Their aim is delivering Internet to the world by providing global broadband coverage. We focus on how such constellations could be leveraged to carry a hosted payload, allowing them to act as navigation satellites. This unprecedented number of satellites gives rise to better geometry than GPS, enabling the use of lower cost clocks. This coupled with the more tranquil LEO radiation environment, allows for a design based on low cost commercial-off-the-shelf (COTS) components. Furthermore, moving from a medium Earth orbit (MEO) where GPS is today down to LEO significantly reduces path loss and makes us more resilient to jamming.
Navigation From Low Earth Orbit by Tyler Reid, Andrew Neish, Todd Walter and Per Enge, Stanford University GPS Lab. Presented at the 2016 Stanford AIAA industrial affiliates meeting.