Aerial Anchors Positioning for Reliable RSS-Based Outdoor Localization in Urban Environments

TL;DR

This paper investigates UAV-based RSS localization in urban environments, deriving an optimal altitude for minimizing error and demonstrating significant accuracy improvements over ground anchors.

Contribution

It introduces a new UAV-based localization scenario considering height-dependent path loss and shadowing, and analytically derives the optimal UAV altitude for minimal error.

Findings

Localization error reduced from over 300m to 80m with UAVs at optimal altitude.

Derived Cramer-Rao lower bound highlights the existence of an optimal UAV altitude.

Simulation confirms improved accuracy in urban outdoor localization using UAVs.

Abstract

In this letter, the localization of terrestrial nodes when unmanned aerial vehicles (UAVs) are used as base stations is investigated. Particularly, a novel localization scenario based on received signal strength (RSS) from terrestrial nodes is introduced. In contrast to the existing literature, our analysis includes height-dependent path loss exponent and shadowing which results in an optimum UAV altitude for minimum localization error. Furthermore, the Cramer-Rao lower bound is derived for the estimated distance which emphasizes, analytically, the existence of an optimal UAV altitude. Our simulation results show that the localization error is decreased from over 300m when using ground-based anchors to 80m when using UAVs flying at the optimal altitude in an urban scenario.