Improving objective measurements of agricultural area using GPS receivers and Unmanned Aerial Vehicles (drones)
Conference
10th International Conference on Agricultural Statistics
Format: CPS Paper - ICAS 2026
Keywords: area, measurement error
Abstract
Reliable agricultural statistics, critical for sound policy, depend on accurate area estimates. Inaccurate measurements introduce compounding biases in the calculation of production and yield statistics. This study details two field exercises in the Cook Islands that developed workflows for using handheld GPS devices and unmanned aerial vehicles (UAVs) to generate more objective area statistics.
The first exercise used handheld GPS receivers, during the 2022 post-Census of Agriculture enumeration survey, to measure parcels and assess bias in farmer self-reports. Compared to GPS measurements, farmer-reported areas were 13% smaller on average. This underestimation was most pronounced for parcels over 2,000 m², while smaller parcels were slightly overestimated.
The second exercise deployed UAVs to capture high-resolution imagery for precise parcel delineation for area measurement and other applications, such as automated fruit-tree counting and crop health monitoring with multi-spectral UAV imagery. While this approach also involved operational constraints (e.g., battery life, regulations, weather), it enabled precise mapping, especially in fragmented agricultural landscapes, inaccessible on foot.