Normalized Difference Snow Index (NDSI) is a numerical indicator that highlights snow cover over land areas. The green and short wave infrared spectral bands are used map the extend of snow cover. Snow and clouds reflect most of the incident radiation in the visible band. However, snow absorbs most of the incident radiation in the short wave infrared, while clouds do not. This enables the NDSI to distinguish snow from clouds.
NDSI is commonly used in snow/ice cover mapping applications and can also be used, subsidiary, in glacier monitoring.
Our Spaceye product uses the short wave infrared and green spectral bands from various satellites (Landsat 8 OLI, Landsat 5 TM, Sentinel 2 MSI) to calculate the NDSI with the following formulas (one for each satellite):
Our NDSI product is produced for the whole globe from 1985 to today with timely temporal resolution!