BRM Localization: UAV Localization in GNSS-Denied Environments Based on Matching of Numerical Map and UAV Images

TL;DR

This paper introduces BRM localization, a novel UAV positioning method in GNSS-denied environments that matches UAV images with numerical maps based on building ratios, improving accuracy without requiring initial coordinates.

Contribution

The paper presents a new GNSS-independent localization algorithm for UAVs that uses building ratio matching with numerical maps, enabling accurate positioning in GNSS-denied areas.

Findings

Achieves better localization accuracy than conventional methods.

Operates effectively without initial coordinate knowledge.

Utilizes only freely available maps for training and matching.

Abstract

Localization is one of the most important technologies needed to use Unmanned Aerial Vehicles (UAVs) in actual fields. Currently, most UAVs use GNSS to estimate their position. Recently, there have been attacks that target the weaknesses of UAVs that use GNSS, such as interrupting GNSS signal to crash the UAVs or sending fake GNSS signals to hijack the UAVs. To avoid this kind of situation, this paper proposes an algorithm that deals with the localization problem of the UAV in GNSS-denied environments. We propose a localization method, named as BRM (Building Ratio Map based) localization, for a UAV by matching an existing numerical map with UAV images. The building area is extracted from the UAV images. The ratio of buildings that occupy in the corresponding image frame is calculated and matched with the building information on the numerical map. The position estimation is started in the range of several km^2 area, so that the position estimation can be performed without knowing the exact initial coordinate. Only freely available maps are used for training data set and matching the ground truth. Finally, we get real UAV images, IMU data, and GNSS data from UAV flight to show that the proposed method can achieve better performance than the conventional methods.