Submitted to: Asian Conference on Precision Agriculture
Publication Type: Proceedings
Publication Acceptance Date: 7/1/2005
Publication Date: 8/4/2005
Citation: Thomson, S.J., F.A. Harris, D.G. Sullivan, D.L. Rowland, and B.W. Maw, 2005. Challenges and solutions for low altitude monitoring of crop status using thermal and reflective techniques. Proceedings of the First Asian Conference on Precision Agriculture, Aug 4-7, 2005, Toyohashi, Japan Interpretive Summary: In site-specific farm management, tillage practices, planting practices, and chemical/water application amounts are tailored to meet the crop’s specific needs according to many factors including soil type, topography, and nutrient and/or water status. To support site specific management, remote sensing data are provided from sensors above the crop, either at close range or high above the field. These data are usually provided in the form of images or electronic signals, which are interpreted so a farm manager can decide where, when, and how much chemical and water to apply to field areas. However, most remote sensing data are not easily accessible for many farm operations due to high cost and the difficulty in obtaining timely information. Two remote sensing platforms being studied at the USDA ARS that show promise for low cost and timely acquisition of data are agricultural aircraft and Unmanned Aerial Vehicles (UAVs). Four remote sensing applications being studied in the humid southern USA are being adapted to these remote sensing platforms. From an aircraft platform, data were obtained for detection of pending crop water stress and pre-plant field status using thermal imagery, for detection of wild host plants that harbor harmful insects, and for detection of cotton maturity level to decide when to terminate insecticide application for cotton. For the water stress study, thermal imagery detected a cooler crop after irrigation. Results were not consistent, however, due to varying cloud cover. Cloud cover effects are being modeled for subsequent studies. Wild host plants were distinguishable using remote sensing and crop maturity level was successfully evaluated to determine when to terminate insecticide application. The onset of plant disease was detectable at the field level in the near-infrared using a digital camera with an optical filter. The plant disease data will be scaled up for use in a remote sensing system on a UAV platform.
Technical Abstract: At the United States Department of Agriculture, Agricultural Research Service (USDA, ARS) and cooperating laboratories, ground-based and low altitude remote sensing platforms are being studied to help simplify feature detection and provide rapid feedback for site-specific farm management. Agricultural aircraft and Unmanned Aerial Vehicles (UAVs) show promise for timely and frequent image acquisition that should promote wider use of remotely sensed data for site-specific management. Remote sensing research being conducted at the USDA, ARS Application and Production Technology Research Unit and cooperating labs is described, along with problems to be considered for practical use of imaging systems in aerial platforms on the farm. The studies highlight the use of thermal and multispectral imagery from aircraft. In addition, data from still-digital photos have potential for detecting plant disease. Imaging procedures from plant disease experiments will be scaled up for implementation in agricultural aircraft and UAVs.