Exploiting Starlink and OneWeb LEO Satellite Signals for High-Altitude Platform Station Opportunistic Navigation

The exploitation of Starlink and OneWeb low Earth orbit (LEO) Ku-band downlink signals of opportunity as a navigation source for a high-altitude platform station (HAPS) is studied. First, the received signal is modeled, and a receiver is implemented to estimate the received Doppler shift. Second, a data collection platform is designed for deployment on a high-altitude weather balloon, ascending to HAPS-equivalent altitudes at nearly 26,000 m. An extended Kalman filter (EKF) is designed to fuse Starlink and OneWeb Doppler measurements with altimeter data, assuming two dynamical models describing the balloon’s dynamics: velocity random walk (VRW) and Wiener process acceleration (WPA). Experimental results are presented showing successful opportunistic navigation with Doppler measurements from 5 Starlink and 1 OneWeb satellites at an altitude around 25,200 m with a trajectory length of 1,398 m traversed in 80 seconds. The achieved three-dimensional (3D) position root-mean squared errors (RMSEs) with the VRW and WPA models were 21.7 m and 17.9 m, respectively, and the final 3D errors were 24.9 m and 13.4 m, respectively.