Monte Carlo Simulation of Altimeter Pulse Returns and Electromagnetic Bias

The electromagnetic bias is a critical error term in sea surface height estimation from satellite radar altimetry. While the electromagnetic bias has been studied extensively, most studies are based on low-order hydrodynamic and electromagnetic models. This paper proposes an alternate approach for electromagnetic bias studies by employing a Monte Carlo procedure with numerical non-linear hydrodynamic simulations coupled with numerical methods for electromagnetic scattering from the sea surface. A deterministic set of sea surface profiles and the corresponding altimeter pulse returns are produced in the simulation. The coupled electromagnetic/hydrodynamic methods can be chosen to tradeoff varying levels of physical fidelity with computational efficiency. The approach allows studies of the impact of various physical effects on the electromagnetic bias. Clear evidence of the electromagnetic bias can be observed in the simulated pulse returns in terms of a shift in the pulse return time.