Optimization of a 50 MHz Frequency Modulated Continuous Wave Radar system for the study of auroral E-region coherent backscatter

A 50 MHz Frequency Modulated Continuous Wave (FMCW) radar system has been developed at the University of Saskatchewan to provide excellent spatial and temporal resolution measurements of auroral E-region plasma processes. An undesirable feature of the otherwise highly effective FMCW system is the introduction of ambiguous spectral information, due to spectral ghosting, for scattering events in which multiple radar echoes are detected. The use of two Linearly Frequency Modulated (LFM) waveforms which extract the range and Doppler frequency information from the radar echoes, is the source of a data association problem, causing the spectral ghosting feature. An alternative frequency coded-CW radar waveform with noise-like properties is investigated as a replacement for the LFM waveforms. The proposed waveform, which is known as a composite Costas waveform, maintains the spatial and temporal resolutions of the FMCW system and prevents data association problems. The implementation of the proposed waveform with state-of-the-art signal generation hardware presents opportunities for the development of a coded-CW mono-static radar system for auroral E-region studies.