Possibilities of using spectral vegetation indices obtained from unmanned aerial vehicle and planetscope systems for different plot sizes

Remote sensing (RS) is an important tool used for fast and efficient monitoring and evaluation of crops throughout the development period. The use of satellite and unmanned aerial vehicle (UAV) systems as remote sensing tools is becoming increasingly widespread today. In order to transform remotely sensed data into information, ground verification studies based on field experiments are increasingly being carried out. UAV systems are mostly preferred in field trials due to the advantage of spatial resolution. However, imaging with UAV systems is more difficult and time consuming than obtaining images from satellite systems. In this study, the possibilities of using multi-spectral images obtained from satellite systems and multi-spectral images taken by UAV systems in monitoring an area where field trials are conducted were evaluated comparatively. Thus, it is aimed to provide a prediction in determining the appropriate plot sizes for the studies to be carried out using satellite images. In this context, analyses were carried out for four different areas as 10m x 10m, 20m x 20m, 40m x 40m and plot level. In this study on sorghum, both high-resolution UAV and PlanetScope satellite images of 24 different dates throughout the season were used. As a result of the evaluations made by using NDVI, SAVI and EVI indices in the study, it was seen that PlanetScope satellite gave mostly compatible results with the UAV. High correlation values of 0,98 for NDVI, 0,97 for SAVI and 0,97 for EVI were observed, especially in 20 m and 40 m areas. For studies of 20 m and above, it was determined that the PlanetScope satellite platform may be more useful.