What is Troposcatter Communications?

Troposcatter Communications are used for beyond line of sight (over the horizon) point to point communications between remote geographic areas where cable links are not feasible. 

Developed in the 1950s, this technology uses particles that make up the lower portion of the earth’s atmosphere (Troposphere) as a reflector for microwave radio signals. In troposcatter propagation, when a signal is aimed towards the troposphere, some part of the radio signal is scattered back to the Earth due to forward scattering in the troposphere. This returning signal is received by a receiver at the other end. But in troposcatter propagation, only a small portion of the signal is scattered forward and reaches the receiver, a major part of the signal is either lost in space or reflects in other directions. 

A troposcatter system has an antenna at both ends, capable of both transmitting and receiving signals, aimed at a fixed point in the troposphere slightly above the horizon. The common region where the antenna beams intersect is the area where the forward scattering phenomenon takes place.