Comparison of Fixed-Wing Unmanned Aircraft Systems (UAS) for Agriculture Monitoring

<p>Florida citrus growers need inexpensive methods to observe citrus plants to detect disease and stress consistently. Health vegetation indices, such as the Normalized Difference Vegetation Index (NDVI) collected from Unmanned Aircraft Systems (UAS), can be used to identify variation in plant health. Simple-to-operate UAS may enable growers to determine within-field variation more frequently than with inspections from scouts, providing more frequent knowledge about the crop condition. This research compared two low-cost fixed-wing UAS, a $5,000 Parrot Disco Pro Ag and a $16,690 senseFly eBee, each equipped with a Parrot Sequoia multispectral camera, to determine if there were differences in the NDVI data results and ease of operation. There were no statistical differences between NDVI reflectance values obtained using the Disco Pro Ag (M = 0.62, SD = 0.15) and the eBee (M = 0.60, SD = 0.15), <em>t</em>(45) = -1.45; <em>p</em> = 0.15. There was a significant positive correlation between the datasets (Pearson correlation = 0.963, <em>p</em> = 0.00). These results suggest that both the Disco Pro Ag and eBee were equally capable of producing the same data from the Parrot Sequoia multispectral camera. Differences in mobility and methods of waypoint planning between these two low-cost UAS may provide remote pilots with different styles of operation. As growers continue to adopt UAS technology to understand their fields better, the characteristics of each system will be important for quick setup time and ease of use.</p>