Research on characteristics of first‐order sea clutter for high‐frequency sky–surface wave radar

Abstract

In high‐frequency (HF) hybrid sky–surface wave radar, the first‐order sea clutter broadening is severe under the influence of the ionosphere and bistatic angle. This affects the detection of ship targets. Thereby a comprehensive analysis is essential and will be presented in this study. First, according to the geometry configuration and detection characteristics of this new system radar, the positioning principle and the range of grazing angle are analysed. Then, the first‐order sea clutter Bragg frequency is presented and broadening model is given on the basis of the system configuration. Next, the mechanism of first‐order sea clutter frequency shift and broadening is explained and, based on the system layout, simulation is provided to illustrate the effects of various factors on first‐order sea clutter, including ionosphere, grazing angle and bistatic angle. Moreover, the characteristics of sea clutter frequency shift and broadening in different range and azimuth are analysed. Finally, the results of theoretical analysis are compared with the experimental data based on the newly‐developed integrated experimental system, and the dominant factor of sea clutter broadening is studied. Simulation results show that the results of experiment are consistent with that of theoretical analysis.

Correction of Ionospheric Distortion on HF Hybrid Sky‐Surface Wave Radar Calibrated by Direct Wave

“…The plusminus sign represents the positive and negative Bragg peaks, respectively. For more information of sea clutter spectrum of wide beam HFHSSW radar, one is referred to the literatures, for example, Jiang et al (2011) and Li et al (2014Li et al ( , 2016.…”

“…HFHSSW radar has an advancement in large-scale environment surveillance and early warning. In the recent decade, a few studies about HFHSSW radar have been conducted on system simulation (e.g., Chen, Huang, & Gill, 2016;Chen et al, 2016aChen et al, , 2016bJiang et al, 2011;Jiao et al, 2007;Li et al, 2016;Walsh et al, 2014Walsh et al, , 2015, system designation and experiment (e.g., Cui et al, 2016;Zhao et al, 2013), application in target over-the-horizon detection (see, e.g., Riddolls, 2007Riddolls, , 2008Zhang et al, 2014), and ocean surface dynamic parameters inversion (see, e.g., Ji et al, 2017;Li et al, 2017Li et al, , 2018.…”

Research on Multimedia Data Information Security Algorithm Based on Chaos Theory

“…With the continuous improvement of scientific and technological levels and the continuous development of Internet technology, it has been widely used in many fields. The transmission of large-scale data information on the Internet network [1][2] needs to play a more critical role in increasing its security and data protection [3]. However, multimedia data information system has their vulnerability because there is much hardware in data information protection system, and the shortcomings of software or data information security methods will lead to significant security risks [4][5].…”