The Proposal of Determining the Focal Length of a Non-Metric Digital Camera for UAV

Abstract

Unmanned Aerial Vehicle - UAV, commonly referred to as drones are vehicles unique in the field of mechanics that can fly in the air without a human operator on board. In recent years, they have become a new interdisciplinary area of science and research. Because they combine photogrammetry, aviation engineering, navigation and automation. Modern UAVs are synchronized with GNSS signals and are remotely piloted or carry out autonomous flights. They can simultaneously perform very complex operations for the implementation of many different civil and military tasks. Currently, drones play an increasingly important role in the modern battlefield and are therefore included in the equipment of all modern world armies. They also find a great potential in civil applications. They are used in many fields of economy, technology and science. Acquiring geoinformation from unmanned aerial vehicles is currently used in the work of many services related to the functioning of the state. In the geomatics, the UAV platforms equipped with specialized sensors, are used to acquire images and photogrammetric and remote sensing data. Photogrammetric projections made by UAV are currently used to generate orthophotomaps, among others for the needs of cadastre. As we know, cadastral measurements, due to their importance, require high accuracy and reliability. They can only be guaranteed by correctly and precisely determined calibration parameters of non-metric cameras. The paper presents a method of determination of the focal length, of a digital non-metric photogrammetric camera. The experimental tests carried out confirmed the usefulness of the proposed calibration method carried out in laboratory conditions.