Assessment of Planetscope Imagery for the "Riserva San Massimo" Rice Farm: Evaluating Benefits and Calibration in Relation to Sentinel-2 Data (Poster)

Previous author’s research demonstrated benefits of PlanetScope images used over “Riserva San Massimo” rice farm (Gropello Cairoli, province of Pavia, Italy): Nor-malized Difference Vegetation Index (NDVI) and Normalized Difference Red Edge Index (NDRE) indices present a seasonal miscalibration, lower during the fertilization period. Spatial resolution is a well-known benefit of PlanetScope images: in this paper the authors investigate its ability to reduce the edge effect compared to the Sentinel-2 images. This problem is relevant for Italy's small crops, due to the increase in the number of pixels crossed by the crops’ boundaries. By quantifying the hybrid pixels, it is possible to demonstrate that PlanetScope helps to reduce the effect by 30% with respect to Sentinel-2, for this farm. Using PlanetScope images in conjunction with the Sentinel-2 experience (agronomic curves known by agronomist G.N. Rognoni) re-quires improved index calibration. The analysis of the 2023 images continued from the previous two-year period (2021-2022), providing substantial data to demonstrate alignment for the entire year through Histogram Matching. The best solution is to perform a calibration with a pair of contemporary images PlanetScope and Sentinel-2 right before the date the PlanetScope image is intended to be used (if the Sentinel-2 is not available for the required day). The amount of PlanetScope images available per year is constantly increasing and it is always likely to find a couple of images without clouds to perform calibration: however, during fertilization period, alignment can be done also with the help of images of previous years.