Some preliminary investigations on the propagation of V.H.F. radio-waves at 126Mc/s in Mountainous terrain

Abstract

This Paper deals with the propagation of VHF radio waves at 126Mc/s within a distance of 2km, on six different paths. Practically observed field strengths have been considered and compared with those theoretically calculated. The observations indicate a difference of about 10-12db on average from the predicated figures for vertically polarized waves which is expected to arise due to absorption by vegetation and the effect of hillocks close by. The differences tend to zero in simpler cases of diffraction not complicated by vegetation etc. An extreme difference of even 25db was observed to be accounted by absorption due to surroundings of vegetation, and buildings.