Sensor: ICESAT GLAS (dataset from 2002 to 2009 have been used)
Resolutions: XY: 0.5 degree. Z: 0.5 m (from 0 to 70 m).
Extent: Global
Data can be accessed here.
Algorithm description: ICESAT Geoscience Laser Altimeter System (GLAS) waveform data contain information on topography (slope) and objects on the surface (mostly vegetation). Vegetation height is derived from the GLA14 product release 31. This product contains the decomposition of waveforms in up to 6 Gaussians. Height is estimated from the difference between the first return, indicative of the top of the vegetation canopy or object, and the ground return.
Accuracy: Algorithms and products were tested on 10 different sites (that were not used for the derivation of algorithms and filters). RMSE of about 5-6 m was estimated. Global patterns correlated well with mean annual ndvi.
Limitations:
- A seasonal effect was found on tree height estimation
- Better estimates were obtained when canopies are in leaf
- Most data were collected during Northern Hemisphere winter
Reference:
Los, S. O. et al. Vegetation height and cover fraction between 60° S and 60° N from ICESat GLAS data. Geosci. Model Dev. 5, 413–432 (2012).