Low elevation angle site diversity satellite communications for the Canadian Arctic

In order to provide reliable satellite communications services for the Canadian Arctic, where geostationary satellite transmissions encounter both low elevation angles and temperature inversion effects during the summer months, a system employing two appropriately separated earth stations is being implemented by Telesat Canada. This space-diverse earth station system, which is the first of its kind for a commercial satellite communications system, is expected to compensate for the atmospheric refractive index irregularities which cause severe 6/4 GHz frequency band signal fluctuations. On the basis of experimental data, the new system's independent signal paths will reduce the required propagation margins from 20 to about 8 dB.