Which vegetation index shows variation better?
Is NDVI the best in the multispectral vegetation index’s family?
The questions are known and coming up very often. Let's investigate.
NDVI (Normalized Difference Vegetation Index) is the most famous and widely used in industries related to biomass and remote sensing. NDVI saturation affects accurate distinguishing of vegetation at biomass peaks. Another issue with NDVI is a soil noise effect on the early stages of crop development.
The NDVI formula is NDVI = (NIR-Red) / (NIR+Red).
The idea of WDRVI (Wide Dynamic Range Vegetation Index) was created to resolve NDVI saturation issues. It was reached with expanding the range of possible WDRVI values via the introduction of the mathematical coefficient (α).
The NDVI formula was transformed into WDRVI = (α∗NIR-Red) / (α∗NIR+Red).
Zones built based on WDRVI are better compared to NDVI zones. Nevertheless, they are still not ideal because of too high biomass.
GCI (Green Chlorophyll Index) is used to estimate leaf chlorophyll content in the plants based on near-infrared and green bands. In general, the chlorophyll value directly reflects the vegetation.
The GCI formula looks like GCI = NIR / Green - 1.
Zones built based on GCI better distinguish high biomass spots compared to NDVI and WDRVI. The details help to manage the field more accurately and efficiently.
RCI (Red Chlorophyll Index) incorporates the same chlorophyll content knowledge base as GCI and reflects it via the red multispectral band.
The RCI formula looks like RCI = NIR / Red - 1.
Zones based on RCI are accurate as GCI zones.
Keep tracking your fields and utilize the right vegetation index at the right moment during the season. A large family of vegetation indices is available in GeoPard right now.