COMPARATIVE ANALYSIS OF UAV AND DSLR PHOTOGRAMMETRY FOR GEOLOGICAL MAPPING OF DINOSAUR TRACKS IN THE FERRON SANDSTONE, CENTRAL UTAH

Photogrammetry, an essential tool in geological mapping, offers high-resolution data that details complex geological structures. This study focuses on geological mapping and compares two prevalent photogrammetric methods: Unmanned Aerial Vehicle (UAV) photogrammetry with real-time kinematics (RTK) using DJI RTK antennas and the Elmid RS2+ base station for centimeter accuracy and traditional DSLR photogrammetry utilizing a Canon 5D Mark III coupled with Canon GP-E2 GPS module. The comparison considers their applications, accuracy, and efficiency in geological contexts.

Both photogrammetry techniques were employed to map the dinosaur tracks across the fourteen by thirty-eight-meter surface of Mary Ann’s Tracksite in the Turonian Ferron Sandstone of central Utah. UAV photogrammetry involved capturing aerial images with a Mavic 3 drone equipped with a 20-megapixel 4:3 frame sensor. UAV images were processed using a structure from motion (SfM) algorithm and Airsoft Meta shape software to generate an orthomosaic photograph. Conversely, DSLR photogrammetry was performed using a full-frame sensor at 22.3-megapixels to take a series of closely-spaced, overlapping ground-based images at a fixed ground height utilizing a tripod, which Agisoft Metashape then processed to generate an orthomosaic photograph.

Our research indicates that UAV photogrammetry prevails in accuracy, speed, and ability to cover large land areas, making it ideal for mapping broad regions. However, when examining finer details, DSLR photogrammetry excels, providing the high-resolution imagery necessary to analyze features like individual dinosaur footprints at a sub-decimeter level. This study offers practical insights for selecting the appropriate photogrammetric method based on specific geological mapping objectives, potentially guiding future geoscience fieldwork strategies in similar geological settings and equipping researchers with valuable knowledge.