A special approach must be used when the ship’s
prow points toward the radar antenna. In this case, the
ship’s silhouette becomes greatly distorted and its shape
properties like symmetry cannot be used as a cue to
identify the prow direction. It has been found experimentally
that the distance between the perimeter and
the centroid is the only useful parameter that can be
used to detect the prow in such cases. To detect this
situation, the R ratio between the ship’s area and the
ship’s centroidal moment is used. If the value of R is
greater than a given value (R>2.5 in the experiments),
the function f(p, Area) uses a different set of weights,
namely KI = 1 and K2 = 0. In this way, the iterative
process does not search for the sharp and symmetric
regions of the contour. The maximum value of p(B) at
the end of the iterative process gives the prow orientation
0.