Efficient Transmitter Selection Strategies for Improved Information Gathering of Aerial Vehicle Navigation in GNSS-Denied Environments

Abstract

Aerial vehicle navigation in global navigation satellite system (GNSS)-denied environments by utilizing pseudorange measurements from <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">M</i> terrestrial signals of opportunity (SOPs) is considered. To this end, the aerial vehicle is tasked with choosing <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">K</i> < <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">M</i> most informative terrestrial SOPs. Two computationally efficient, but sub-optimal, transmitter selection strategies are proposed. These selection strategies, termed opportunistic greedy selection (OGS) and one-shot selection (OSS), exploit the additive, iterative properties of the Fisher information matrix (FIM), where OGS selects the most informative transmitters in finite iterations, while the OSS selects in one-iteration. Monte Carlo simulation results are presented comparing the OGS and OSS strategies versus the optimal (exhaustive search) selection strategy, where it is concluded that OGS performs closely to the optimal selection, while executing in a fraction of the optimal selection's time. Experimental results are presented of a U.S. Air Force high-altitude aircraft navigating without GNSS signals in (i) a rural region and (ii) a semi-urban region. The performance of the aircraft's navigation solution with the selected SOP transmitters via optimal, OGS, OSS are compared over a flight segment where the selection remained valid. The position root mean-squared error (RMSE) with the optimal, OGS, and OSS were 4.53 m, 6.28 m, 7.13 m in the rural region; and 5.83 m, 6.08 m, 6.70 m in the semi-urban region for an aircraft traversing a trajectory of 1.48 km and 1.22 km, respectively.