Atmospheric structure, transhorizon propagation, and their relationship to remote sensing

Previous papers suggest that the characteristics of atmospheric structure cannot be inferred unambiguously from transhorizon scatter measurements. It is shown that the form of the refractivity spectrum can be correctly inferred from appropriate beam-swinging measurements. One analysis includes contributions from both scattered and partially reflected components of the transhorizon signal, and shows how the characteristics of the angular response pattern of the received signal varies with changes in these components. Analytically derived patterns are compared with measured response patterns. The form of the refractivity spectrum inferred from the comparison is consistent with the form suggested from physical arguments and by the results of independent transhorizon experiments. Because the transhorizon signal includes scattered and partially reflected signals, remote-sensing techniques using transhorizon methods should employ both signal components to correctly derive atmospheric parameters. Finally, both of these signal components should be used for channel models that use adaptive algorithms to optimize the design of troposcatter communication networks.