Short waves in the electromagnetic bias theories

Most previous theories on the altimeter electromagnetic bias (EM-bias) have focused on long waves and their influence through high-order surface statistics. A modification is presented based on the two-scale philosophy where short waves are tilted and modulated by longer ones. Short waves are found to have an essential effect on the EM-bias revealed in the directionality of short wave versus long waves. Known dependence of the EM-bias on radar frequency is also captured by the inclusion of the slope variances of short waves in the final EM-bias formulation. This new theory will be demonstrated using a general numerical simulation. Comparison with empirical models derived from TOPEX/Poseidon data will also be made for various wind speeds and radar frequencies