A Comparative Study of MODIS and Sentinel-2 Data Using NDVI and EVI
Research and Technical Final.pdf (5.445Mb)
MetadataShow full item record
The increasing availability of remote sensing data in the past few decades has enabled researchers to study ecosystems and the carbon cycle on a global scale in increasingly fine detail. The MODIS sensors on the Aqua and Terra satellites have been among the most commonly used systems for this ecological research. MODIS has a relatively low spatial resolution however, so the potential for new systems with higher resolutions is an exciting prospect in the field. One such system is the Sentinel-2 twin satellites launched by the European Space Agency in 2015 and 2017. Because Sentinel-2 data has not been fully explored, literature on its use for measuring various ecological factors is largely non-existent. The aims of this report are to compare NDVI and EVI values from established MODIS products and Sentinel-2 data across 12 study sites in northern Australia and southern Africa and account for any observed differences. This study showed that while MODIS accurately described the phenology of these regions, the Sentinel-2 data showed little correlation to MODIS NDVI and EVI values. The discrepancy was enough so that neither regional nor seasonal vegetation changes could be adequately observed with the Sentinel-2 data. While the relationship varied slightly between study sites, the comparison using all sites produced r2 values that did not exceed 0.5. The poor correlation between MODIS and Sentinel-2 was most likely caused by a series of limitations, including high levels of cloud cover, issues performing the atmospheric corrections, and resolution differences between the two sensors.