Green Chromatic Index (GCI) also known as Green Chromatic Coordinate (GCC) is a measure of the greenness of vegetation. It is calculated from daily averaged RGB (Red, Green, Blue) composites values of digital images captured by PhenoCams.
Abisko Scientific Research Station (2024). Phenocam - Green Chromatic Coordinates (GCC) Composite Image Mean Values from Abisko Scientific Research Station, 2024-04-01–2024-07-02 [Data set]. Swedish Infrastructure for Ecosystem Science (SITES). https://hdl.handle.net/11676.1/srX-mF-rt6jwMSzr14ouIcdB