Effect of Multipath on Ranging Error for an Airplane-Satellite Link

An exact analysis is carried out on the effects of noise and surface scatter multipath on the one-way ranging errors of a singlesideband tone ranging modem used in an airplane-satellite link. With appropriate redefinition of parameters the results are shown to apply approximately to double-sideband tone ranging modems at high signal/ noise and signal/multipath ratios. The theoretical results are applied to obtain numerical results on ranging error for typical system geometries and sea states and for a representative hemispherical-coverage aircraft antenna. Multipath is shown to cause larger ranging errors than previously indicated. The need for additional channel measurements is pointed out.