Calculation of the Multipath Factor

It is a known fact that in radar applications targets on or near the surface of the sea will interact with the sea surface and have an effect on the returned signal. The returned signal will be the product of the targets free space radar cross section and the wave propagation factor for the situation. The wave propagation factor can vary from 0 to 16. The wave propagation factor is called the Multipath factor, hence the term M-factor. The M-factor is the factor that will take the wave propagation into consideration for a radarsystem and the object that is illuminated by the radar. Because of different reasons there has not been any real documentation of how the M-factor is calculated other than short comments in the code earlier written within the FOI. The purpose of this report is therefore to document how the M-factor is calculated.