Issue link: https://www.e-digitaleditions.com/i/1432253
WATER USE imagery is and build models to make it as precise as possible. The models serve as a sort of "corrective lens" for the satellite imagery as it pertains to almonds specifically. With a refined model, growers will be able to use data throughout the season that is accurate on a sub-field level. Eyes in the Skies In addition to the orchard data and the satellite imagery, the T-REX project incorporates drone imagery to help refine the model and to help advance research into the viability of using these tools in regular irrigation operations. Drones, or unmanned aerial vehicles (UAVs), have advantages over satellite imagery in that they can also collect both thermal and optical data at sub tree-scale resolution. This data can separate the almond tree from the inter-row conditions, quantify the health status and canopy temperature per almond tree, and map out tree geometry and leaf density. This is helpful in determining crop water stress, allowing growers to plan irrigation timing and identify management zones within the orchards with more accuracy. "We're ground-truthing from the top down and also validating from the bottom up… so we're getting to that finer spatial level of detail," said Mallika Nocco, cooperative extension specialist in soil-plant water relations and irrigation management from UC Davis. Nocco and colleagues are flying a commercially available DJI Matrice 210 RTK drone at a height of 90 meters above the ground with a MicaSense Altum camera that is designed to help monitor crop water stress. These are tools that a grower could potentially buy to help monitor water stress, but Nocco wants to make sure that the information will be accurate and actionable. "When you do a flyover to create a map, you're capturing an instant in time. That's a snapshot," said Nocco. "So we need to be able to understand what we're seeing with the maps and to scale that up to an accurate daily estimate." Nocco hopes this research could advance the technology so that drone imagery could have the same accuracy as using a pressure chamber. That way, growers could just fly a drone instead of taking pressure chamber samples, making the process cheaper, easier, and more descriptive of the entire orchard. Nocco thinks drones could also play a Continued from page 10 McElrone and the team used three handheld evapotransporation (ET) detectors to get real-time readings from the tree canopy. 11