Case Study: Virginia Polytechnic Institute and State University advances GPS backup positioning with MathWorks MATLAB and Satellite Communications Toolbox

Exploring Doppler-Only Positioning of Low-Earth Orbit Satellites as a GPS Backup

Virginia Polytechnic Institute and State University (Virginia Tech) researchers were tasked with finding a GPS backup due to the system's vulnerability to threats. They needed to investigate if Doppler-only positioning using low-Earth orbit (LEO) satellite constellations, which requires fewer simultaneously visible satellites, could be a feasible and accurate alternative.

Using MathWorks MATLAB and Satellite Communications Toolbox, the team modeled satellite orbits and performed a global visibility analysis. This proved that, on average, at least five satellites are in view from any location. They then developed scripts to calculate a specialized metric (D-GDOP_T), demonstrating that time-diverse measurements from just four satellites could achieve positioning accuracy comparable to a traditional eight-satellite approach. MathWorks' proven toolbox functions gave the team confidence in their results and saved them significant programming and code review time.

Virginia Polytechnic Institute and State University

Megan O. Moore

Virginia Polytechnic Institute and State University