Who can use this feature
Editors of a project within a Professional or Pro + workspace.
The greenness index in remote sensing is a measure used to assess the amount of green vegetation in a particular area. It is commonly derived from satellite, drone, or other aerial imagery and helps in monitoring and managing natural resources and agricultural practices.
Note that this is NOT the same as the normalized difference vegetation index (NDVI), which requires multispectral data to calculate.
Greenness index calculation
The greenness index is calculated on GeoNadir using the following equation:
GI = green / (red + green + blue)
where red, green, and blue are the pixel values in an orthomosaic in those respective bands.
This equation is applied to an RGB drone orthomosaic. You will then be able to view your image with a green colour ramp. The darker the green colour (approaching a value of 1), the higher the greenness index value. Lighter colors (approaching a value of 0, displayed as light green / white) are less green.
Below you can see an RGB orthomosaic and how it is rendered with the greenness index applied (data supplied courtesy New Jersey Sport and Exposition Authority).
Applying the Greenness index
Select a dataset on the table of contents
Click the 'greenness index' icon on the top menu bar
Remember to check that the dataset is visible (eyeball switched on), and that the dataset you are viewing is on top of any other datasets. Otherwise it will be hidden and you won't see the effect.
You can also apply the greenness index via the style bar.
Click the dataset icon next to the dataset in the table of contents to open the style bar (or use the keyboard shortcut
's')Change from 'true color' to 'greenness index'.
To remove the greenness index and revert to the RGB display
Click the dataset icon next to the dataset in the table of contents to open the style bar (or use the keyboard shortcut
's')Change from 'greenness index' to 'true color'.
Inspecting Greenness index values
If you'd like to know the value of specific pixels, check out our Inspect tool. Make sure that you have the greenness index displayed first.
To learn more about the greenness index check out our blog about mangrove mapping.