Radar System Engineering

SEC. 3.13] SEA R.ETCR.V A.YD GRO~.YD RE1’CR.\” 93
confusion between sea and land. Sea return is strongest in the direction
from which the wind is blowing, This effect is shown clearly in Fig.
3.22, which not only shows substantial sea return in the upwind and downwind
directions (north and south), with no visible return in directions
crosswind from the radar, but also shows a much weaker sea return in
the protected inner harbor than in the outer harbor.
N
For microwave radar most land areas are wholly on the rough side
of the division between rough and smooth surfaces-primarily because of
the presence of vegetation, Because the ground is thoroughly rough,
the aspect function F(fI) of Sec. 3.11 takes, for ground return, the followin~
simple form:
F(6) = K sin 0, (32)