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Normalized Difference Snow Index

Landsat Collection 2 Normalized Difference Snow Index (NDSI) is the normalized difference between green (G) spectral bands and the shortwave infrared (SWIR).

Return to Landsat Surface Reflectance-derived Spectral Indices Overview

The Landsat Surface Reflectance-derived normalized difference snow index (NDSI) are produced from Collection 2 (C2) Landsat 4-5 Thematic Mapper (TM), Landsat 7 Enhanced Thematic Mapper Plus (ETM+), and Landsat 8-9 Operational Land Imagery (OLI)/Thermal Infrared Sensor (TIRS) scenes that successfully process to Landsat Collection 2 Level-2 Surface Reflectance products.

Landsat Collection 2 Normalized Difference Snow Index Example
This graphic shows an example of the Landsat Collection 2 Surface Reflectance-derived Normalized Difference Snow Index (NDSI) near Sacramento, California. Left: Landsat Collection 2 Surface Reflectance image; Right: Landsat Collection 2 NDSI image. (Landsat 9, WRS-2 Path 44, Row 32, Acquired November 27, 2022 )

The C2 NDSI science product is the normalized difference between spectral bands green (G) and the shortwave infrared (SWIR). The NDSI is particularly useful for separating snow from vegetation, soils, and lithology endmembers. The NDSI uses the TM and ETM+ Bands 2 and 5, whereas for OLI the algorithm uses Bands 3 and 6:

 (G – SWIR1) / (G + SWIR1)

In Landsat 4-7, NDSI = (Band 2 – Band 5) / (Band 2 + Band 5)

In Landsat 8-9, NDSI = (Band 3 – Band 6) / (Band 3 + Band 6)

The probability that snow is present is proportional to how close the NDSI pixel value is to 1 (range –1 to 1).

NDSI is delivered as a single band product, specified as shown in the table below.


Attribute Value
Long Name Normalized Difference Snow Index
File Name SR_NDSI
Data Type Signed 16-bit integer
Units Band Ratio Index Value
Valid Range -10000 to 10000
Fill Value -19999 
Scale Factor 0.0001

Data Access

Landsat Collection 2 Surface Reflectance-derived NDSI are produced on-demand, using the USGS Earth Resources Observation and Science (EROS) Center Science Processing Architecture (ESPA) On Demand Interface.

Visit the Landsat Surface Reflectance-Derived Spectral Indices webpage for information on product constraints, citation, and reference information.