Question

The following digital numbers are given for a pixel of multispectral sensor. The NDWI (normalized difference water index) for this pixel is ............................. (Rounded off to 1 decimal place).

• A. 0.1
• B. 0.2
• C. 0.5
• D. 0.4

Hint:

NDWI is typically used to highlight water bodies in remote sensing imagery. It uses the Green and NIR bands and is commonly applied in vegetation and water studies.

Answer 1

The Correct Option is A

The Normalized Difference Water Index (NDWI) is given by the formula: \[ \text{NDWI} = \frac{\text{Green} - \text{NIR}}{\text{Green} + \text{NIR}}. \] Substitute the values for Green = 200 and NIR = 150: \[ \text{NDWI} = \frac{200 - 150}{200 + 150} = \frac{50}{350} = 0.142857. \] Rounding to 1 decimal place, the NDWI is: \[ \boxed{0.1}. \]