The calculation of normalized difference vegetation index (better known as “NDVI”) of a particular location – it is not always an easy and straightforward task. Indeed, in such cases, it is important to pay attention not only on the pixels that fall within the geodetic chain (it is fully marked milestones in the pictures and maps).

Also, it is necessary to focus on the areas, where the pixels are captured in part. How do the calculation pixel NDVI in such cases?

There are two important points in the solution of this problem.

Fragment of the normalized vegetation difference map / precisionagricultu.re

Fragment of the NDVI map / precisionagricultu.re

Firstly, the main rule – the calculation is only in integer pixels. Though, undoubtedly, a role of pixel average value essentially depends on the software being used. Also, be aware that in the case of mapping large areas, the result of a calculation is also affected by the map projection image.
Secondly, the need to focus on the fact that under ideal conditions when calculating a pixel average, the weight of the pixel must be correlated in proportion to the share of its area, which hit the landfill.