Image Index is a “synthetic image layer” created from the existing bands of a multispectral image. This new layer often provides unique and valuable information not found in any of the other individual bands. Image index is a calculated result or generated product from satellite band/channels It helps to identify different land cover from mathematical definition .

1. Image Indices Kabir Uddin International Centre for Integrated Mountain Development Mountain Environment & Natural Resources’ Information System (MENRIS) Kathmandu, Nepal www.icimod.org

3. Band/Channel of Satellite Image There are different type of Band/ Channel Following Band/Cannel are commonly used Band 1 0.45 - 0.52µm (blue) Band 2 0.52 - 0.60µm (green) Band 3 0.63 - 0.69µm (red) Band 4 0.75 - 0.90µm (nir) Band 5 1.55 - 1.75µm (infra-red) Band 6 10.4 - 12.50µm (tir) Band 7 2.08 - 2.35µm (nir) Band 8 0.52 - 0.90µm (pan)

11. Land and Water Masks (LWM) Index values can range from 0 to 255, but water values typically range between 0 to 50 Water Mask = infra-red) / (green + .0001) * 100 (ETM+) Water Mask = Band 5) / (Band 2 + .0001) * 100

12. Modification of Normalized Difference Water Index (NDWI) Index values can range from 0 to 255, but water values typically range between 130 to 255 NDWI=(NIR – infra-red) / (NIR + infra-red) (ETM+) NDWI = (Band 4 - Band 5) / (Band 4 + Band 5)

13. Green normalized difference vegetation index Index values can range from 0 to 255, but vegetation values typically range between 150 to 255 GNDVI=(NIR - Green) ÷ (NIR + Green) (ETM+) GNDVI = (Band 4 - Band 2) / (Band 4 + Band 2)

14. Normalized Difference Moisture Index Index values can range from –1 to +1 , but vegetation values typically range between 0 to 1

15. Soil Adjusted Vegetation Index (SAVI) SAVI = (NIR - red) / (NIR + red) NDVI (ETM+) = (1.5* ((Band 4 - Band 3) / (Band 4 + Band 3) +.05))