Capturing Carbonate Platform Margin Topography With High-Resolution Drone Photography

Abstract

Drones are changing the way geologists map in that it is now possible to acquire high-resolution photographs and elevation data of inaccessible locations. The University of Miami CSL – Center for Carbonate Research together with Camera Wings Aerial Photography conducted a field mapping survey on a portion of New Providence Island and at several localities in the Exuma Cays of the Bahamas. Camera Wings designs, builds, and operates drones, which are outfitted with the latest automated flight control systems, highest resolution digital cameras, and position data loggers to capture high-resolution oblique photographs and conduct photogrammetry. They have developed a Quad Copter configuration drone that offers unparalleled flight time and vertical take off and landing. Through the use of previously unattainable data acquired by the drone, we can now measure elevations and quantify key geomorphic features in the Bahamas field areas caused by the Holocene transgression and Pleistocene sea-level oscillations. Flight operations were conducted from the Clifton Heritage National Park on New Providence, and the deck of John G. Shedd Aquarium's research vessel R/V Coral Reef II in the Exumas. Photos were stitched using Agisoft software and corrected with ground control points. Oblique aerial photographs were also shot and stitched to create life-like virtual 360° panoramas of key field areas. The drone imaging combined with advanced photogrammetry software allow us to use this new data to produce elevation models known as “Digital Terrain Models” (DTMs) which are viewable with popular imaging software including ArcGIS and Google Earth. DTMs offer accurate high-density point fields with the added advantage of photo draping provided by photogrammetry. The varied types of images acquired have different applications and will be key new sources of data in ongoing investigations: (1) individual frames provide unique views for key sedimentologic and stratigraphic perspectives, (2) merged photo mosaics are used for constructing DTMs and for accurate measurements of features, (3) oblique 360° panoramas offer unique perspectives, and (4) merged, overlapping horizontal frames are used for continuous outcrop interpretation and measurements.

AAPG Datapages/Search and Discovery Article #90216 ©2015 AAPG Annual Convention and Exhibition, Denver, CO., May 31 - June 3, 2015