Over-the-horizon radar sensitivity enhancement by impulsive noise excision

This paper describes a signal processing algorithm that increases radar sensitivity by as much as 20 dB, after excising noise impulses, such as those caused by lightning, from the temporal data stream at the receiver output. The work was performed at the California-based Wide Aperture Research Facility (WARF) high-frequency (HF) over-the-horizon radar (OTHR) for enhancement of the U.S. Navy relocatable OTHR (ROTHR) (AN/TPS-71). The key to the algorithm's success is the removal of clutter from the Doppler domain prior to inverse transforming to the time domain for the purpose of impulsive noise detection and removal. The impulsive noise excision (INE) methodology is straightforward, and should have application to various communication systems and Doppler radars that operate at other radio frequencies.