Why link losses are more as the antenna height decreases in ground to air comm
Theoretically free space loss is independent of the height of the transmitting and receiving antenna. However when link loss is calculated in ground to air v/UHF communication, the link loss varies with the airborne receiving height of the antenna. With transmitting antenna on ground at constant height, as the receiving antenna height increases, the losses are reduced.
I want to know what is the reason for decrease in losses as the receiving antenna height increases. This phenomena is observed as per various propagation models.
Can one please explain the actual physics behind this ?