Simulation of radar altimeter waveforms over ocean and ice covered regions
Initially satellite altimeters were developed to measure ocean surface heights.
But they also provide measurements over continental ice sheets and sea ice
covered regions. Radar altimeters operating over ice covered regions are subject
to additional error sources. The return scatter depends on the surface slope and
surface roughness and is also affected by the extinction coefficient and the
reflection inside the snow and ice layers. Therefore these parameters have to be
well known for interpreting the power and the signal of the pulse response. Since
it is almost impossible to determine the parameters continuously at the surface, the
computational simulation of the waveform is a suitable tool to get a better
understanding of the impact of the surface conditions on the reflected signal.
For this purpose a waveform simulator has been developed which takes into
account prominent topographic features due to the discretisation of the
surfaces. We will present the results of various simulations of waveforms
for different states of the surface and for several topographic features
like shelf ice edges and ice floes.
Using the waveform simulator will allow us to develop adapted retracking
functions and will lead to a better estimation of sea surface heights in
sea ice covered regions.