Remote Sensing Tool

GNDVI Calculator

Calculate Green Normalized Difference Vegetation Index from Green and NIR Reflectance Values quickly and accurately.

GNDVI =

( NIR - Green )
---------------------
( NIR + Green )
GNDVI RESULT
0.0000
Unknown
Green: 0.00
NIR: 0.00
Rounded: 0.00

GNDVI Formula & Interpretation

What is GNDVI?

GNDVI (Green Normalized Difference Vegetation Index) is a spectral vegetation index used in remote sensing to estimate chlorophyll concentration and assess vegetation health. It is an alternative to the popular NDVI.

Instead of the Red band used in NDVI, GNDVI utilizes the Green band alongside the Near-Infrared (NIR) band.

GNDVI = (NIR - Green) / (NIR + Green)

GNDVI Value Interpretation

GNDVI values range from -1.0 to 1.0. Note that interpretation depends on crop type, sensor, and growth stage, but a general guide is:

< 0.00 Non-vegetation / Water / Snow
0.00 – 0.20 Low Vegetation / Bare Soil
0.20 – 0.40 Moderate Vegetation
0.40 – 0.60 Fairly High Vegetation
0.60 – 0.80 High Vegetation
> 0.80 Very High Vegetation

Green Band vs NIR Band

Green Band

The Green spectral band (approx. 530-590 nm) reflects more light from healthy vegetation compared to the red and blue bands. GNDVI utilizes this sensitivity to green light, making it highly responsive to changes in chlorophyll-a and -b concentrations.

NIR Band

The Near-Infrared band (approx. 780-890 nm) is strongly reflected by the internal spongy mesophyll leaf structure. Healthy vegetation with dense canopies reflects vast amounts of NIR energy.

GNDVI Applications in Remote Sensing

Values of Green and NIR are derived from surface reflectance data obtained from satellite sensors (e.g., Sentinel-2, Landsat 8/9) or multispectral drones. Applications include:

GNDVI vs NDVI

While both are vegetation indices, they serve slightly different purposes. GNDVI is often preferred in mid-to-late crop stages because it is less prone to saturation than NDVI.

Parameter GNDVI NDVI
Green Band Used Not Used
Red Band Not Used Used
NIR Band Used Used
Formula (NIR - Green) / (NIR + Green) (NIR - Red) / (NIR + Red)
Primary Use Case Chlorophyll concentration, dense canopies General vegetation vigor, biomass

Frequently Asked Questions

What is GNDVI?
GNDVI (Green Normalized Difference Vegetation Index) is a vegetation index that uses Near Infrared (NIR) and Green bands to assess vegetation health and chlorophyll concentration.
What is the GNDVI formula?
The formula for GNDVI is: GNDVI = (NIR - Green) / (NIR + Green).
What bands are required for GNDVI?
GNDVI requires the Green band (typically 540-570 nm) and the Near-Infrared (NIR) band (typically 780-890 nm).
What does a high GNDVI value mean?
A high GNDVI value (typically above 0.60) indicates dense, healthy vegetation with high chlorophyll content.
Can GNDVI be negative?
Yes, GNDVI can be negative. Values below 0 typically represent non-vegetated surfaces like water, snow, or bare soil.
Can I use satellite imagery for GNDVI?
Yes, GNDVI is commonly calculated using multispectral satellite imagery from sensors like Landsat, Sentinel-2, or drones equipped with multispectral cameras. Ensure you use atmospherically corrected surface reflectance data.
Can GNDVI be used for agriculture?
Absolutely. GNDVI is widely used in precision agriculture to monitor crop health, estimate nitrogen content, and detect plant stress before it becomes visible to the human eye.
What is the difference between NDVI and GNDVI?
While NDVI uses Red and NIR bands, GNDVI uses Green and NIR. GNDVI is often more sensitive to chlorophyll concentration and less prone to saturation in dense canopies compared to NDVI.