"I would recommend the new logarithmic swept sine available in the new WinMLS beta version. This method is better than MLS for long distance measurements (because of the robustness to time-variance due to wind and temperature gradients)."
The main problem with long distance (greater than 10 meters) radiation pattern measurements is temperature gradients can literally blow the signal around. This make amplitude measurements very hard and phase measurements impossible. That is presently why loudspeaker manufacturers do not do phase measurements.
It seems like some type of reference acoustical channel is needed to compensate for temperature gradients. I do not understand how any measurement technique (TEF, MLS, dual channel FFT or log sweep) can compensate for changing atmospheric conditions.
