Using a UAV for Remote Sensing of California Beach Vegetation

Studying vegetation on California's beaches has been problematic with remote sensing. Commonly available imagery, such as satellite imagery or aerial photographs, may not be of sufficiently large scale to identify species of beach plants, which rarely form large dense stands. Large amounts of light reflected from the sand can obscure plants in aerial photographs. Fine scale imagery collected over the site, on site, could provide the solution to some common remote sensing problems associated with beach vegetation. A balloon-mounted camera was flown over UCSB's Coal Oil Point Reserve to collect aerial photographs with one pixel corresponding to three to five mm2 on the ground. The lower flying height and greater flexibility in timing of image acquisition with an unmanned aerial vehicle (UAV) proved to be a satisfactory solution. This study tested the feasibility of using a UAV to collect usable remote sensing data for the beach ecosystem, and identifies the spectral signatures of four common plant species and four types of substrate at one beach.