How to compare two data of NDVI

Agriculture
1

Hi, I need to some digital value to compare two date of NDVI to show the growth progress of tree.

Older date B NDVI

B NDVI
B NDVI472×921 310 KB

and New date A NDVI

A NDVI
A NDVI469×934 283 KB

From the circle, you can see the A is better than B. But what is the amount or percentage? anyway to calculate it?

Is it possible get a percentage for B for example 45%, and A is 56%. Then we know the A is better than B. Then we can monitor next month.

2

Hi,

what you can do is:

  1. Create a Polygon Annotation for Layer A, which covers your AOI.
  2. export it and import it to Layer B.
  3. Compare the mean index value on the right sidebar between both Layers
  4. Divide B/A *100 to get the percentage.

image
image1213×1004 234 KB

More advanced analysis can be done with QGIS and Zonal Statistics.