Dragonette-1 GEMI
Global Environmental Monitoring Index for Dragonette-1
Vegetation Satellite Provider: Wyvern
Applications
global vegetation monitoring
atmospheric effect mitigation
vegetation cover assessment
biomass estimation
environmental monitoring
satellite-based vegetation analysis
Quick Stats
Category: vegetation
Sensor: Dragonette-1
Provider: Wyvern
Bands Used: 2
Description
The Global Environmental Monitoring Index (GEMI) is a non-linear vegetation index developed by Pinty and Verstraete (1992) specifically designed to reduce atmospheric effects without requiring detailed atmospheric correction. Unlike NDVI, GEMI maintains information about vegetation cover while being more resistant to atmospheric perturbations.
Formulas
General Formula
Dragonette-1 Specific Formula
eta * (1 - 0.25 * eta) - ((Band 16 - 0.125) / (1 - Band 16)) where eta = (2 * (Band 23^2 - Band 16^2) + 1.5 * Band 23 + 0.5 * Band 16) / (Band 23 + Band 16 + 0.5)Spectral Band Visualization
Band Wavelengths
RED: 640-760
NIR: 780-1400
Code Examples
gemi2.py
References
Pinty, B. and Verstraete, M.M. (1992) - GEMI: A non-linear index to monitor global vegetation from satellites. Vegetatio, 101, 15-20