HR: 17:45h
AN: B24B-08    [Abstracts]
TI: Employing UAVs to Acquire Detailed Vegetation and Bare Ground Data for Assessing Rangeland Health
AU: * Rango, A
EM: alrango@nmsu.edu
AF: USDA-ARS-Jornada Experimental Range, 2995 Knox St., NMSU, MSC 3JER, PO Box 30003, Las Cruces, NM 88003, United States
AU: Laliberte, A
EM: alaliber@nmsu.edu
AF: USDA-ARS-Jornada Experimental Range, 2995 Knox St., NMSU, MSC 3JER, PO Box 30003, Las Cruces, NM 88003, United States
AU: Herrick, J E
EM: jherrick@nmsu.edu
AF: USDA-ARS-Jornada Experimental Range, 2995 Knox St., NMSU, MSC 3JER, PO Box 30003, Las Cruces, NM 88003, United States
AU: Winters, C
EM: craigwin@rmi.net
AF: USDA-ARS-Jornada Experimental Range, 2995 Knox St., NMSU, MSC 3JER, PO Box 30003, Las Cruces, NM 88003, United States
AB: Because of its value as a historical record (extending back to the mid 1930s), aerial photography is an important tool used in many rangeland studies. However, these historical photos are not very useful for detailed analysis of rangeland health because of inadequate spatial resolution and scheduling limitations. These issues are now being resolved by using Unmanned Aerial Vehicles (UAVs) over rangeland study areas. Spatial resolution improvements have been rapid in the last 10 years from the QuickBird satellite through improved aerial photography to the new UAV coverage and have utilized improved sensors and the more simplistic approach of low altitude flights. Our rangeland health experiments have shown that the low altitude UAV digital photography is preferred by rangeland scientists because it allows, for the first time, their identification of vegetation and land surface patterns and patches, gap sizes, bare soil percentages, and vegetation type. This hyperspatial imagery (imagery with a resolution finer than the object of interest) is obtained at about 5cm resolution by flying at an altitude of 150m above the surface of the Jornada Experimental Range in southern New Mexico. Additionally, the UAV provides improved temporal flexibility, such as flights immediately following fires, floods, and other catastrophic disturbances, because the flight capability is located near the study area and the vehicles are under the direct control of the users, eliminating the additional steps associated with budgets and contracts. There are significant challenges to improve the data to make them useful for operational agencies, namely, image distortion with inexpensive, consumer grade digital cameras, difficulty in detecting sufficient ground control points in small scenes (152m by 114m), accuracy of exterior UAV information on X,Y, Z, roll, pitch, and heading, the sheer number of images collected, and developing reliable relationships with ground-based data across a broad range of topographies and plant communities. Our efforts are currently focused on developing a complete and efficient workflow for UAV operational missions consisting of flight planning, image acquisition, image rectification and mosaicking, and image classification. The remote sensing capability is being incorporated into existing rangeland health assessment and monitoring protocols.
DE: 0430 Computational methods and data processing
DE: 0434 Data sets
DE: 0439 Ecosystems, structure and dynamics (4815)
DE: 0480 Remote sensing
DE: 9805 Instruments useful in three or more fields
SC: Biogeosciences [B]
MN: 2007 Fall Meeting