TABLE OF CONTENTS Given this specification of the sea surface, we must now capture its interaction with the incident microwave radiation. The behaviour of this electro magnetic field is governed
Here E and H are the electric and magnetic field in tensities, D is the electric displacement and B is the magnetic induction; ? and j are charge and current densities satisfying the conservation relation
The field intensities are related to the associated displacement and induction through constitutive relations
If harmonic time dependence exp( ? i ?t) is assumed in 3.28 the equations become
We are interested in the free space above the sea (where ? = ? = 1) and the sea itself, which is an imperfect electrical conductor. We can describe the finite electrical conductivity of sea water by setting ? = 1 and taking ? to have a large imaginary part and a real part greater than unity. This allows us to suppress the j in equation (3.31) as it is accounted for by the imaginary part of ?. At the sea surface the fields satisfy boundary conditions that require that the tangential components of E and B and the normal components of E and D are continuous.
Calculation of the scattered field from the sea surface for a particular radar illumination may be done in the time domain by using equation...
