Question

In a Landsat-8 scene, digital number (DN) values of a pixel in band-4, band-5 and band-10 are 80, 100 and 30, respectively. What would be the NDVI value for the same pixel (round off to 3 decimal places)?

• A. 0.111
• B. 0.222
• C. 0.556
• D. 0.889

Hint:

NDVI is a widely used vegetation index that helps in determining the presence and health of vegetation. A value closer to 1 indicates healthy vegetation.

Answer 1

The Correct Option is A

The Normalized Difference Vegetation Index (NDVI) is calculated using the formula: \[ NDVI = \frac{(NIR - Red)}{(NIR + Red)} \] Where: - NIR = DN value in band-5 (100)
- Red = DN value in band-4 (80)
Thus, the NDVI is calculated as: \[ NDVI = \frac{(100 - 80)}{(100 + 80)} = \frac{20}{180} = 0.111 \] Step 1: Understanding the NDVI formula. NDVI uses the reflectance in the near-infrared (NIR) and red bands to indicate vegetation presence. A higher NDVI value indicates more vegetation.
Step 2: Conclusion. The calculated NDVI value for the given bands is 0.111, making option (A) the correct answer.
Thus, the correct answer is (A).