Investigation of ionospheric clutter using ionosondes in mid-latitude and arctic regions aimed at feasibility assessment of the high-frequency surface-wave radar surveillance

This paper studies ionospheric clutter conditions and compares ionosonde measurements in the mid-latitude and arctic regions to determine the most favourable conditions for HFSWR surveillance for surface vessels and low-altitude air targets. The best time to perform HFSWR surveillance is between approximately 06:00-15:00 UT and 20:00-00:00 UT. During these hours, the number of days that sporadic-E interference occurs in a month and the range of frequencies reflected is minimized compared to other times of the day. Of the sites considered, Resolute Bay is the most favourable site for HFSWR surveillance in the summer since sporadic-E interference occurs least often, resulting in reduced signal interference. Similarly, Eureka is the preferred site during the winter months. In addition, the ionosphere at Eureka generally reflects the lowest range of maximum frequencies (similar to 4 - 8 MHz), again resulting in less clutter interference. In all the observations, polar cap sites Eureka and Resolute Bay yield results that are less prone to sporadic-E interference than the mid-latitude site Cambridge Bay.