SOME METEOROLOGICAL INVESTIGATIONS OF THE PERFORMANCE OF 2 TROPOSCATTER LINKS IN NORTHERN INDIA

Troposcatter communication links, in spite of their importance having been declined with the advent of satellite communication, still play v ital role in battle fronts. The performance of these links is critical ly dependent on the vertical fluctuations of refractivity in the first few kilometres. The performance and reliability of two troposcatter l inks situated in the northern India have been evaluated. Simultaneous measurements of meteorological parameters and signal levels showed tha t refractivity gradients in the common volume are better correlated wi th signal levels and sub-refractive gradients in the common volume are responsible for weak signal levels observed in the afternoon hours an d sometimes in the late evening hours. As the present space/frequency diversity system is not able to counteract the link outages effectivel y, a combination of space/angle diversity system is proposed because a ngle diversity can work better under sub-refractive conditions than ot her diversity systems.