New Mexico Geological Society Annual Spring Meeting — Abstracts

Uncrewed Aircraft Systems (UAS/drones) have proven to be valuable tools in geological fieldwork/research. However, collecting ad hoc UAS imagery is time-consuming, generates enormous datasets, and prevents researchers from utilizing imagery to its full potential. UAS can supply geologists with a wide range of data such as elevation models for landforms, geologic structures, geomorphic processes and even geochemical alteration patterns. However, the benefits and limitations of using UAS must be taken into consideration when incorporating them into geoscience workflows. Iterative and intentional workflows provide a method for integrating UAS data collection into research projects by encouraging structured data collection and management plans. In order to conduct UAS research flights in the US, researchers must consider regulatory, logistical, and institutional issues. Flights must comply with FAA regulations and some universities/institutions require all pilots and observers to take additional internal safety courses. Additionally, before a flight can take place, flight planning is essential for promoting a safe and productive operation.

As part of course GEOL 520- Drones in Geosciences at New Mexico State University and to explore the integration of UAS in geology, sites near to Las Cruces, NM, were selected for their specific geologic workflow attributes. Aerial imagery was collected with a DJI Phantom 4 Advanced then processed in Agisoft Metashape. Through five case studies presented here, the integration of UAS with geologic fieldwork is explored, including the benefits/limitations and workflow-specific considerations of flight planning, data collection, and processing/interpretation. (1) Near Soledad Canyon, imaging for 3D outcrop modeling was done to resolve m-scale mineralized joint sets, cm-scale igneous flow textures throughout the outcrop, their cross-cutting relationships, and spatial attitudes by calibrating the UAS flight distance and angles necessary to capture images that display these small structures at high resolution. (2) To observe stratigraphic relationships and architecture in the Abo Formation in Lucero Arroyo, UAS images were captured from a distance of 10-15 m from multiple angles (nadir and oblique) to resolve vertical features within the outcrop. (3) When developing a digital outcrop model (in the Bishop Cap Hills) for building a measured section, UAS imagery must provide sufficient resolution to recognize fine bedform features and geometries. Workflows for generating such a model require greater consideration for UAS flight altitudes, image densities, and processing resolution qualities. (4) To refine the understanding of lava flow morphology and resolve flow features at Aden Lava Flow, NM, UAS imagery was collected for creation of orthomosaic maps and 3D outcrop models. (5) Also at Aden Lava Flow, imagery was collected at 50 and 100 m flight altitudes to experimentally calculate the Ground Sampling Distance of the UAS camera and provide guidelines for flight altitudes necessary to resolve fine- vs large-scale geologic features. These examples highlight the wide range of UAS applications in geoscience research and education, and the importance and necessity of integrating UAS workflows at all stages to ensure that flights are conducted in a safe, planned, and integrated manner.