The document provides detailed specifications on the Landsat 8 bands, including their wavelengths and resolutions, focusing on the importance of using the Normalized Difference Vegetation Index (NDVI) to assess vegetation density. It outlines the process of calculating NDVI using QGIS and discusses resampling and filtering techniques for image enhancement. Additionally, it includes references for further reading and accessing global NDVI data.

1. Normalized Differentiate Vegetative Index

2. Bands Wavelength
(micrometers)
Resolution
(meters)
B1 - Ultra Blue 0.435 - 0.451 30
B2 - Blue 0.452 - 0.512 30
B3 - Green 0.533 - 0.590 30
B4 - Red 0.636 - 0.673 30
B5 - NIR 0.851 - 0.879 30
B6 – SWIR 1 1.566 - 1.651 30
B7 - SWIR 2 2.107 - 2.294 30
B8 - Pan 0.503 - 0.676 15
B9 - Cirrus 1.363 - 1.384 30
B10 - TIRS 1 10.60 - 11.19 100 * (30)
B11 - TIRS 2 11.50 - 12.51 100 * (30)
Band Specifications of Landsat - 8

3. EMR -Vs- Spatial Object
Credits : https://www.sciencedirect.com/science/article/pii/S1110982317300327

4. Bands correspond to Vegetation
Credits : https://landsat.usgs.gov/atmospheric-transmittance-information
http://gsp.humboldt.edu/OLM/Courses/GSP_216_Online/lesson2-1/vegetation.html

5. Bands correspond to Vegetation
Credits : https://earthobservatory.nasa.gov/Features/MeasuringVegetation/measuring_vegetation_2.php
If there is much more
reflected light in
Near-infrared wavelengths
than in visible wavelengths,
then the vegetation in that
pixel is likely to be dense
- EarthObservatory, NASA

6. Normalized Differentiate Vegetation Index
Vegetation - NDVI
NDVI
Credits : https://en.wikipedia.org/wiki/Normalized_difference_vegetation_index
Red
InfraRed
NDVI result

7. Computing NDVI using QGIS
Load raster layers representing
Red and Infrared bands in QGIS

8. Computing NDVI using QGIS
Go to main menu
>> Choose Raster
>> Raster Calculator
Output
Formula
Input

9. Representation of NDVI using QGIS
Range of NDVI : -1 to +1
Higher value (towards 1)
- Density of vegetation
Lower value (towards -1)
- Lack of vegetation
(bare soil, built-up area, etc)
NDVI :
(NIR – Red)
(NIR + Red)
Access Global NDVI @
http://www.fao.org/giews/earthobservatio
n/asis/index_2.jsp?lang=en
Ref: Raster styling in QGIS

10. Resampling
Load Raster layer to be resampled to QGIS
Processing Toolbox >> Search for Resampling Algorithm
(eg:) >> Resampling with BSpline Algorithm
r.resamp.bspline - Performs bilinear or bicubic spline
interpolation with Tykhonov regularization.
Image Enhancement techniques
Edge Enhancing
Load Raster layer to be resampled to QGIS
Processing Toolbox >> Search for Filtering Algorithms
(eg:) >> Choose Remove Small Pixels with BSpline Algorithm
Many Filtering Algorithms - Performed with bilinear or bicubic
interpolations to remove chunks.
Try with many other image enhancement algorithms.........

11. Try with other filtering algorithms...
Compare
Un-filtered and Filtered
Image Enhancement techniques
Here is an output of enhanced image using Resampling and Edge-Enhancement