Impacts of Satellite Revisit Frequency on Spring Phenology Monitoring of Deciduous Broad-Leaved Forests Based on Vegetation Index Time Series

Satellites have different revisit frequencies (i.e., temporal resolutions), ranging from daily to monthly. The satellite suitable for accurately monitoring the phenology of deciduous broad-leaved forests (DBF) are not well-known. To fill this knowledge gap, study used MODIS Daily Nadir BRDF-Adjusted images simulate EVI time series with a wide range resolutions 52 days, investigate impacts frequency on spatial and patterns spring phenology, i.e., start season (SOS), DBF in North America. Then, these were extract SOS by two common extraction methods relative threshold curvature methods). Our results reveal that 1 ) low cannot reconstruct real vegetation growth profile, which generally causes false early detection, 2 impact is nonlinear. accuracy detection data relatively high (e.g., 7 days) only slightly lower than but decreases largely frequencies, 3 validation ground observations PhenoCam Network stations an experiment using three datasets MODIS, Landsat 8, Sentinel-2) confirm findings our simulation study. This suggests satellites medium resolutions, such as Sentinel-2 could reliable metrics non-cloudy regions.