The calculation of the antenna gain for a path between Trx1 and Trx2 is performed as follows:
Gain in horizontal plane: if horizontal antenna pattern is defined, then 
Gain in vertical plane: if vertical antenna pattern is defined, then: 
When the two antenna patterns (horizontal and vertical) are selected, this means that the Horizontal and vertical planes are combined and SEAMCAT calculates the resulting antenna gain as a pseudo 3-D antenna gain . The calculation is based on the following approximation with a treshold value of 3 dB:
IF abs(
) < 3 dB
(in linear domain - not in dB) (Eq. 158)
else
(in linear domain - not in dB) (Eq. 159)