The effect of uniform layers on the propagation of radio waves

Almost everyone who has studied anomalous propagation in the troposphere will agree that the controlling factors are temperature and humidity profiles along the propagation path. However, when one tries to correlate propagation data against refractive index profiles as computed from temperature and humidity data, one immediately encounters the difficulty of a large scatter of points. In this case, one is often tempted to attribute the scatter to unknown influences which have not been taken into account.