So called antenna patterns represent changing the intensity of electromagnetic radiation. When the antenna works as the receiver, radiation patterns show changing in the voltage on the antenna connector. Both patterns have the same shape for receiving and transmitting.
Radiation characteristics can be calculate by checking a voltage on the output of the test antenna (the test receiver) while it is moving along principal planes H and V (the gain vs. azimuth or the gain vs. elevation).
Radiation paterns for Elboxrf antennas are calculated for main polarizations planes and for various frequencies: the lowest, the middle and the highest of operational frequency. But for the clarity on the product page patterns are given for a middle operational frequency. For example, the TetraAnt Pro 5 60 18 X has the frequency range 5.1 to 6.2 GHz, so patterns are for 5.5 GHz, but for other frequency patterns are available upon request.
Patterns are based on a raw data available as the results of the electromagnetic simulation in the thee dimensional - 3D - environment (we are talking about the numerical environment in the computer program).
Data are as accurate as the simulation is - we can also to model various structures like a mounting mast or the antenna close-in wall structure, but the standard for visualization antenna patterns is to model antenna in an empty environment without scattering structures.