A waveform model for surface and volume scattering from ice and snow

摘要

A method for combining surface and volume scattering effects to model the radar altimeter power waveforms recorded over continental ice and snow, such as that present on Greenland and Antarctica, is discussed. The surface model that is used is a variant of the well-known impulse response based method that is capable of modeling the returns for an altimeter having a general configuration of altitude, antenna beamwidth, transmitted pulsewidth, and pointing angle. The newly formulated volume model is also an impulse response based method that differs from previously introduced versions in that it can also be applied to a general altimeter configuration. The two models are added together assuming completely incoherent scattering. An example of fitting this combined model to altimeter data is given to illustrate the importance of accounting for the volume scattering present in ice/snow data. An optimization method can then be used to achieve a least-squares fit to actual altimeter data, providing an estimate of the parameters for that area on the ice shelf.