Comparison of Side-Lobe Cancellation Techniques Using Auxiliary Horizontal and Vertical Antennas in HF Surface Wave Radar

摘要

Side-lobe cancellation techniques are evaluated using auxiliary horizontal and vertical antennas in HF surface wave radar (HFSWR). The aim of the evaluation is to compare the pros and cons of using horizontal dipoles or vertical monopoles as auxiliary antennas in HFSWR. A radar experiment was carried out to facilitate this comparison. Four horizontal dipoles, configured in the form of two separate crosses, and six vertical monopoles of a HFSWR system were used in the experiment. In this report, the central four monopoles are used as main antennas, and either two of the horizontal dipoles or the other two vertical monopoles are used as auxiliary antennas. A synthetic target signal was injected into the radar data. The effects of the cancellation techniques on the target signal are evaluated. As expected, if the target signal is coming from the same direction as the interfering signal, it is cancelled when the vertical monopoles are used as auxiliary antennas. The same target signal, however, is still visibly present when the auxiliary horizontal dipoles are used. This latter result was obtained in spite of the fact that the horizontal antennas also received the radar signal.