A Compact Direction-Finding Antenna for HF Remote Sensing

A compact four-element antenna, along with a numerical direction-finding algorithm, is analyzed using computer simulations that model sea-echo data obtained with an HF pulsed Doppler radar. The algorithm consists of closed-form expressions and is capable of deriving the angles-of-arrival for one or two signals impinging upon the antenna. Errors associated with the calculated angles are presented as a function of signal-to-noise ratio. In addition, it is demonstrated that preaveraging antenna voltages over independent data samples can decrease the angle errors and extend the range of the radar.