Differences between NDVI calculated using Band math and the NDVI processor

Optical Toolbox
1

I’ve recently calculated NDVI for a specific area via SNAP and Sentinel 2 images. I used both ways to do it - Band Maths and NDVI Processor. but the result is quite different. which one is more precise?
image

2

Hello @satas12825,
If you save the product with both NDVI bands (calculated with NDVI Op and Band Maths), close it, and reopen it, will the values still be different?

3

Sorry for the late response, it is still different

4

Could you provide your SNAP version and the expression and parameters used for Band Maths and NDVI Op?
Thank you!

5

thank you for your help ,I’m using snap 9.0.6 and the expression was (band8-band4)/(band8+band4)

6

Hi @satas12825,

We need you to do two more tests:

  1. Export the product containing the two bands as csv (File → Export → CSV) and check if the exported pixel values are different.
  2. Open the product in SNAP. Open the two bands. In the Navigation window, click on image Zoom Actual Pixel. Check the pixel value in the Pixel Info window. Do you still have different values?