The remote characterization of vegetation using Unmanned Aerial Vehicle photography

TitleThe remote characterization of vegetation using Unmanned Aerial Vehicle photography
Publication TypeConference Paper
Year of Publication2008
AuthorsRango A., Laliberte, Andrea S., Winters C, Maxwell CJ, Steele C
Conference NameAGU 2008 Fall Meeting
Date PublishedDecember 15-19,
Conference LocationSan Francisco, CA
ARIS Log Number235485
Keywordsremote sensing, UAV, Unmanned Aerial Vehicles
AbstractUnmanned Aerial Vehicles (UAVs) can fly in place of piloted aircraft to gather remote sensing information on vegetation characteristics. The type of sensors flown depends on the instrument payload capacity available, so that, depending on the specific UAV, it is possible to obtain video, aerial photographic, multispectral and hyperspectral radiometric, LIDAR, and radar data. The characteristics of several small UAVs less than 55lbs (25kg)) along with some payload instruments will be reviewed. Common types of remote sensing coverage available from a small, limited-payload UAV are video and hyperspatial, digital photography. From evaluation of these simple types of remote sensing data, we conclude that UAVs can play an important role in measuring and monitoring vegetation health and structure of the vegetation/soil complex in rangelands. If we fly our MLB Bat-3 at an altitude of 700ft (213m), we can obtain a digital photographic resolution of 6cm. The digital images acquired cover an area of approximately 29,350sq m. Video imaging is usually only useful for monitoring the flight path of the UAV in real time. In our experiments with the 6cm resolution data, we have been able to measure vegetation patch size, crown width, gap sizes between vegetation, percent vegetation and bare soil cover, and type of vegetation. The UAV system is also being tested to acquire height of the vegetation canopy using shadow measurements and a digital elevation model obtained with stereo images. Evaluation of combining the UAV digital photography with LIDAR data of the Jornada Experimental Range in south central New Mexico is ongoing. The use of UAVs is increasing and is becoming a very promising tool for vegetation assessment and change, but there are several operational components to flying UAVs that users need to consider. These include cost, a whole set of, as yet, undefined regulations regarding flying in the National Air Space(NAS), procedures to gain approval for flying in the NAS(FAA Certificate of Authorization), and training(remote control piloting, UAV-specific instruction, FAA ground school and testing, FAA observer procedures, FAA medical Class 2 exam, and a private pilot's license). The relevance and need of all these to developing a UAV capability will be explained. While working through the necessary requirements above, we have also learned that we need to know how to handle extremely large and easily acquired data sets as well as to develop tools to orthorectify and mosaic individual UAV images for analysis.