Silvilaser 2019 - Poster Presentations »
PRELIMINARY VALIDATION OF THE ICESAT-2 LAND WATER VEGETATION ELEVATION PRODUCT (ATL08)
The new Ice, Cloud and Land Elevation Satellite-2 (ICESat-2) mission provides various data product for land ice, sea ice, the atmosphere, vegetation and land, oceans and inland water. Of interest to the vegetation community are the Geolocated Photon Data (ATL03) that contain precise latitude, longitude and elevation for every received photon and the Land Water Vegetation Elevation product (ATL08), which comprises terrain and canopy height information. Given the novelty of photon counting data to the vegetation community and its susceptibility to solar background noise, there is a great need to develop methods for analyzing and validating ICESAT-2 datasets. In this study, we present preliminary assessment results on deriving terrain elevation and vegetation canopy height from ICESAT-2 global geolocated photon data (ATL03) data granules. Our methodology, which has already proved effective on simulated ICESAT-2 data, applies a multi-level noise filtering approach to minimize noise photons and subsequently classifies the remaining photons into ground and top of canopy using an overlapping moving window method and cubic spline interpolation. We assessed our methodology on ATL03 data granules across selected sites in California and Oregon by comparing derived ground and canopy estimates with existing airborne lidar data, we also used to validate ATL08 ground estimates. Overall, the multi-level filtering process shows great promise in identifying background noise and preserving signal photons in the raw data but continued testing will be needed to adequately document its strengths and weaknesses with respect to estimating vegetation biophysical parameters.