Cross-polarization measurements at 4 and 6 GHz in the Intelsat V system

Attention is given to cross polarization discrimination (XPD) measurements at 4 and 6 GHz in the dual-polarized Intelsat V system of FDM/FM/FDMA communications carriers transmitted from seven earth stations in the Atlantic Ocean region. These data provide examples of the effects of depolarization in the actual Intelsat system operating environment. Up-link XPD levels that are not exceeded 0.01 percent of the time range from 8.2 to 25.6 dB for the various stations. Significant XPD degradations resulted from both antenna and propagation effects, with the latter being the most common.