ICESat-2 volume scattering bias

Abstract:

The Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) is the 2nd-generation of the orbiting laser altimeter ICESat. ICESat-2 will use a 532 nm photon counting laser altimeter, which is a change from the 1064 nm waveform altimeter used on ICESat. Snow and ice have much lower absorption at the 532 nm than the 1064 nm wavelength and therefore a higher fraction of emitted photons will be returned to the range detector. However, lower absorption results in an increase in the number of scattering events that occur within the snow and ice (volume scattering). If not properly corrected for, volume scattering can result in spatially and temporally coherent time delays in photon returns that result in a low bias in derived surface elevations. We provide a summary of our preliminary findings into the potential magnitude and time evolution of volume scattering on elevations derived from ICESat-2 data.