Abstract

Accurate unmanned aerial vehicle (UAV) trajectory estimation is essential for autonomous navigation, particularly in GPS-denied environments. Visualodometry and simultaneous localization and mapping (SLAM) approaches require precise camera intrinsic parameters, which are typically obtained through predefined or offline calibration. Instead, in this work, we propose a reinforcement learning (RL)-based self-calibration framework that estimates camera intrinsic parameters directly from monocular video sequences, without requiring prior knowledge of the camera, environment, or calibration targets. This intrinsic parameter estimation is then leveraged to achieve robust UAV trajectory estimation using only video data. We formulate the problem as a sequential decision-making task, where an RL agent iteratively refines intrinsic parameters (focal lengths and principal point) by minimizing projection error. The proposed framework is implemented using the Soft Actor-Critic (SAC) algorithm, which is well-suited for continuous action spaces and promotes efficient exploration. We validate our approach on real-world datasets, which provide ground truth intrinsic parameters and trajectory data. Our results demonstrate that the estimated intrinsic parameters enable effective UAV trajectory reconstruction in GPS-denied environments, showing promising results. Thereby, this approach enables the estimation of the UAV's 3D trajectory without prior knowledge of the camera.

Department(s)

Electrical and Computer Engineering

Second Department

Computer Science

Publication Status

Early Access

Keywords and Phrases

Camera self-calibration; Horizontal trajectory estimation; Reinforcement learning; SIFT features; Soft Actor-Critic (SAC); UAV navigation

International Standard Serial Number (ISSN)

1557-9603; 0018-9251

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2026 Institute of Electrical and Electronics Engineers, All rights reserved.

Publication Date

01 Jan 2026

Share

 
COinS