A comparison of biophysical parameter retrieval for forestry using airborne and satellite LiDAR

This paper compares vegetation height metrics and fractional cover derived from coincident small footprint, discrete return airborne Light Detection and Ranging (LiDAR) scanning data (Optech Airborne Laser Terrain Mapper (ALTM)) with those estimated from large footprint, full waveform LiDAR profiling using the Geoscience Laser Altimeter System (GLAS). Estimates of maximum canopy height showed correspondence between the two methods with R = 0.68 (rms. error (RMSE) = 4.4 m). The relationship between 99 percentiles (often associated with forestry top height) showed R = 0.75, RMSE = 3.5 m. Detection of surface elevation limits corresponded well, (R = 0.71, RMSE = 5.0 m). Correlations between satellite waveform and airborne LiDAR canopy cover estimates gave R = 0.41 and R = 0.63 for dominant cover of conifers or broadleaf species, respectively. The results suggest that the broad Ice, Cloud and land Elevation Satellite (ICESat)/GLAS footprints can provide estimates of mixed vegetation canopy height which are comparable to those obtained from relatively high density airborne LiDAR data