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ARS Home » Plains Area » Lubbock, Texas » Cropping Systems Research Laboratory » Wind Erosion and Water Conservation Research » Research » Publications at this Location » Publication #424019
Research Project: Developing Strategies for Resilient and Sustainable Crop, Water, and Soil Management in Semi-Arid Environments

Location: Wind Erosion and Water Conservation Research

Title: Quantifying temporal distortions of artificial UAV crop canopy temperature measurements

Author
item Goebel, Timothy
item MAHAN, JAMES - Goannaag Pty Ltd
item PAYTON, PAXTON - Goannaag Pty Ltd
item Young, Andrew
item Pugh, Nicholas
item Xin, Zhanguo
item Stout, John
item Gitz, Dennis
item Lascano, Robert

Submitted to: Remote Sensing
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/27/2025
Publication Date: 6/30/2025
Citation: Goebel, T.S., Mahan, J.R., Payton, P., Young, A.W., Pugh, N.A., Xin, Z., Stout, J.E., Gitz, D.C., Lascano, R.J. 2025. Quantifying temporal distortions of artificial UAV crop canopy temperature measurements. Remote Sensing. 14(2). https://doi.org/10.4236/ars.2025.142006.
DOI: https://doi.org/10.4236/ars.2025.142006

Interpretive Summary: The temperature of the plant canopy of a crop can be measured with thermal sensors called radiometers. These sensors are normally placed in close proximity to the plants providing a continuous measurement but of a small area of the canopy. One way to overcome this area limitation is to mount the radiometers on a drone that can cover large areas, depending on the battery size. Typically, the battery of a small drone provides about one hour of flight and on a clear day in the semiarid environment of Lubbock during the cotton growing season, the air temperate can increase by 5 or more F. This change in temperature as measured with a thermal sensor mounted a drone introduces misleading information on the water status of the crop and thus would complicate the evaluation of plants under differnet irrigation treatments. Scientists of the ARS in Lubbock working with scientists from a commercial company formulated an experiment to evaluate this distortion in plant canopy temperature. In this experiment the scientists introduced an artificial data set of drone measurements of plant canopy temperature with a time delay that ranged from 15 minutes to 2 hours.

Technical Abstract: The crop canopy temperature (Tc) measured with fixed-infrared thermometers (IRT’s), provides dense temporal values but only measure small areas of the canopy. Conversely, thermal sensors mounted on UAVs measure Tc over larger areas, overcoming this limitation. However, these measurements may introduce distortions in the Tc’s values due to the time of day when they are measured. We measured Tc of a cotton crop over a growing season using fixed-IRTs and compared these measurements to the same data with an assumed time delay of 0.25 – 2 hours. This delay was used as a proxy of Tc values measured with a UAV. The dataset consisted of 7 IRTs measuring 96 values/d over 67 days. Results showed that artificial UAV flight missions resulted in a thermal distortion related to the flight duration. This distortion was applied to detect differences of Tc in seven irrigation treatments. The difference in Tc from the UAV and fixed IRT was affected by the time of day, irrigation treatment, and UAV-flight duration. To identify irrigation treatments, the assumed UAV-Tc produced up to 27% spurious treatment differences relative to the fixed-IRT. Distortion in UAV-Tc were minimal for flights of < 15-minutes. Interpretation of UAV-Tc data should consider this distortion.