Does the area size affect agriculture indices results?

Agriculture
1

Hello,

I have a question please and not sure if it’s a logical one, does the area size affect the results of indices like NDVI on the EO Browser?
Is it worth using the satellite images (remote sensing) to monitor small areas .03 km2?
I hope my question is clear. Any thoughts, recommendations, advice are very welcomed!

Thanks in advance
Nida

2

Hi Nida,

It all depends on the resolution of the imagery that you are using, more particularly the size of your area of interest (AOI) compared to the pixel size.

Let’s take the example of Sentinel-2 (which is commonly used to calculate NDVI) and your example area of 0.03 km2: your AOI would contain approximately 300 pixels which should be largely sufficient to monitor NDVI within the AOI. If you were to do the same with Sentinel-3 OLCI for example, then your AOI would be completely contained within 1 pixel (assuming a square shape for simplicity), but that pixel would return a mixed signal from your AOI and part of its surroundings. In that case, hard to get any significant information about your AOI…

I hope I understood your question correctly :slight_smile:

3

Hi @maxim.lamare

Thanks so much for the clarifications! based on this, I think I did a right job :slight_smile: as I used Sentinel – L2A to monitor the NDVI and NDMI over time for the same location.

I was looking for some resources that provide clarifications on such matters for people with limited khnowledge of remote sensing, but couldn’t find.

best
nida