Enhanced OTHR ship detection via dual frequency operation

Ship detection by means of HF skywave radar is limited by: (i) sea clutter whose intrinsic Doppler spectrum extends over most of the relevant frequency band; (ii) signal distortion and contamination during ionospheric propagation. In this paper we present an analysis of a technique for enhancing detectability by means of dual frequency transmissions. Simulated sea clutter is convolved with measured ionospheric transfer functions to demonstrate the efficacy of this approach.