Tropospheric scatter

Troposcatter also tropospheric radio or via radio horizon is the propagation of radio waves which are scattered back to the troposphere. This ranges up to 200 km are possible, which can not be achieved with a radio link due to the curvature of the earth.

Because of the low backscatter signals of high transmission power and directional antennas are required for Tropospheric. One example was before the establishment of communications satellites, the White Alice Communications System in Alaska. The system installed in the states of the Warsaw Pact troposphere message system " BARS " was also based on this effect.

Tropospheric scatter is not to be confused with tropospheric overreach of FM signals at temperature inversion.

Example Berlin

A well-known application of the over - horizon radio relay was the realization of a microwave link between the Federal Republic of Germany and West Berlin in the 1950s to the 1990s.

Only the connection from the sender Gartow direction Berlin- Frohnau was a direct radio link ( about 133 km as the crow ), which could be ensured due to the very large amount of the two poles (mast Gartow: 344 m; mast Frohnau: 358.58 m).