HFSWHigh Frequency Surface Wave
HFSWHigh Frequency Sight Words
References in periodicals archive ?
Data from national collection means, including signals intelligence and acoustic systems, over-the-horizon radars such as the ROTHR * and HFSW systems, sighting reports by Navy, Coast Guard, and Customs vessels and aircraft, human intelligence, and acoustic sensors would be melded with the transponder-supplied positions to determine the presence of nonreporting vessels or tracks displaying abnormal behavior or with suspicious histories.