Polarization of a dipole antenna - Ludwig 3 polarization

Dear all,,,

I am using CST MWS to simulate the polarization of a dipole antenna.
The dipole is alligned with the y' axis and the main beam along the z' axis.
The dipole length is (lambda/2).

When I switch to Ludwig 3 system and select the (abs) component, I get exactly the doughnut shape.

However, when I select Ludwig 3 (vertical), I get the doughnut between 0<theta<90, and a very strange shape between 90<theta<180.

Does this mean that Ludwig 3 representation is valid only for 0<theta<90?

Thanks in advance.

I would be grateful if at least someone tell me the difference between (Az/El) and (Ludwig 3) definitions

is there any picture which illustrates the vector orientation of ludwig 3 definition?
thanks.