akar.earthGEDI: Definition
What is GEDI? NASA's spaceborne lidar on the International Space Station that measures forest canopy height and supports tropical biomass mapping.
GEDI (Global Ecosystem Dynamics Investigation) is a NASA lidar instrument mounted on the International Space Station that fires laser pulses at the Earth to measure the vertical structure of forests. Each pulse records a footprint about 25 m across, giving canopy height and structure metrics for temperate and tropical forests.
Why it matters
Before GEDI, lidar data for tropical forests came mostly from costly airborne surveys covering small areas. GEDI provides millions of structure samples across the tropics, including Indonesia. Researchers and vendors use it to calibrate canopy height and biomass maps built from optical and radar imagery, which has improved biomass estimates in regions with few field plots.
How it is used
- Canopy height and relative height metrics (for example the height at which a set share of returned energy is reached).
- Footprint-level and gridded above-ground biomass products, produced with models calibrated against field and airborne lidar data.
- Training data for machine learning models that predict height wall-to-wall from Sentinel-2, Landsat or radar.
Read our GEDI lidar guide and canopy height models for workflows.
Indonesia and Southeast Asia angle
Indonesia falls within GEDI’s coverage band, and the data is valuable for high-biomass lowland and peat swamp forests where optical data saturates. Steep terrain in Sumatra, Sulawesi and Papua affects footprint accuracy, so slope filtering matters. For project work, GEDI is best used to support a design built on local field plots and, where budgets allow, drone or airborne lidar.
Mission operations have varied over time, so data availability differs by year and region. Check the current data archive and versions before planning a time series around GEDI.
Common mistakes
- Treating footprint biomass as plot-level truth for a small project.
- Ignoring geolocation error of footprints when matching them to field plots.
- Using footprints from different years without accounting for growth or disturbance.
See remote sensing for biomass for how GEDI fits with other data.
Frequently asked questions
Does GEDI give wall-to-wall coverage?
No. GEDI samples footprints along its orbit tracks with gaps between them. Wall-to-wall maps need to combine GEDI with optical or radar imagery.
Can a carbon project rely on GEDI alone?
No. GEDI footprints are sparse at project scale and carry their own error. They are useful for calibration and checking, alongside field plots.