• radar
• skywave
• waveform

Since 1960, Over the Horizon radars have been studied; they fall into two types: Sky-wave and Surface-wave radar systems, classified as
a function of electromagnetic waves propagation mode. The HF-OTH skywave performance strongly depends on several space-time variant factors
such as, propagation channel, external noise (environment and man-made noise) and frequencies national plan usage. This implies that a HF
system must have a high level of adaptively in order to fit the external constrains. This thesis is concerned with a software-defined frequency
management system whose main task is to select the transmitted frequencies and elevation angles to be used in transmission according to the ionosphere channel, external noise intensity and available channels; special attention was paid to the study of waveforms and specifically to development of a technique for set the waveform parameters in an adaptive way depending on the operating modes.

A System architecture accomplish the work.