Integrating PPP-AR into UAV-based Photogrammetry: Constellation and Accuracy Evaluation Mehmet Arkali, Muhammed Enes Atik
ISTANBUL TECHNICAL UNIVERSITY
Abstract
The integration of Global Navigation Satellite System (GNSS) technology into unmanned aerial vehicles (UAVs) has significantly improved the positional accuracy of photogrammetric products. The availability of multiple GNSS constellations has greatly improved positioning capabilities. At the same time, advances in space geodesy and satellite technology have contributed to the development of new methodologies aimed at improving the accuracy of GNSS. Previous studies using GNSS-integrated UAVs have primarily focused on relative positioning techniques. However, there has recently been a shift towards the use of precise point positioning (PPP), a special form of absolute positioning. The PPP method enables the accurate estimation of 3D coordinates using GNSS data obtained from a single receiver operating at single or multiple frequencies. This study aims to investigate the performance of various GNSS constellation combinations in UAV-based photogrammetry using the PPP-AR (PPP-Uncertainty Resolution) technique. Thus, the visibility and number of satellites in each constellation, as well as their effect on positioning, have been examined. The PPP technique utilizes code and phase ambiguities, as well as precise satellite orbit and clock products, and can be applied in real-time or through post-processing. The ability of a single GNSS receiver to determine global positioning makes the PPP technique particularly noteworthy. With advancements in multi-frequency and multi-GNSS capabilities, positioning accuracy has improved due to the increase in the number of observable satellites and frequencies. The PPP technique has been utilized for many years to meet basic positioning needs, as well as for geodetic purposes and various scientific applications. In UAV-based photogrammetry studies, the PPP method is accepted as an alternative to RTK and PPK techniques.
