scholarly journals Observation of Zenneck-Like Waves over a Metasurface Designed for Launching HF Radar Surface Wave

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Florent Jangal ◽  
Nicolas Bourey ◽  
Muriel Darces ◽  
François Issac ◽  
Marc Hélier
Keyword(s):  
Surface Wave ◽  
High Frequency ◽  
Dielectric Medium ◽  
Hf Radar ◽  
Dielectric Slab ◽  
High Frequency Band ◽  
High Attenuation ◽  
Wave Radar ◽  
Infrared Method ◽  
Constant Interest

Since the beginning of the 20th century a controversy has been continuously revived about the existence of the Zenneck Wave. This wave is a theoretical solution of Maxwell’s equations and might be propagated along the interface between the air and a dielectric medium. The expected weak attenuation at large distance explains the constant interest for this wave. Notably in the High Frequency band such a wave had been thought as a key point to reduce the high attenuation observed in High Frequency Surface Wave Radar. Despite many works on that topic and various experiments attempted during one century, there is still an alternation of statements between its existence and its nonexistence. We report here an experiment done during the optimisation of the transmitting antennas for Surface Wave Radars. Using an infrared method, we visualize a wave having the structure described by Zenneck above a metasurface located on a dielectric slab.

scholarly journals Research on Polarization Cancellation of Nonstationary Ionosphere Clutter in HF Radar System

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Xingpeng Mao ◽  
Hong Hong ◽  
Weibo Deng ◽  
Yongtan Liu
Keyword(s):  
Surface Wave ◽  
Time Domain ◽  
High Frequency ◽  
Interference Cancellation ◽  
Radar System ◽  
Experimental Results ◽  
Hf Radar ◽  
Oblique Projection ◽  
Polarization Filter ◽  
Wave Radar

Oblique projection polarization filter (OPPF) can be applied as an effective approach for interference cancellation in high-frequency surface wave radar (HFSWR) and other systems. In order to suppress the nonstationary ionosphere clutter further, a novel OPPF based clutter suppressing scheme is proposed in this paper. The polarization and nonstationary characteristic of the clutter are taken into account in the algorithms referred to as range-Doppler domain polarization suppression (RDDPS) and the range-time domain polarization suppression (RTDPS) method, respectively. The RDDPS is designed for weak ionosphere clutter and implemented in the range-Doppler domain directly, whereas the RTDPS algorithm is designed to suppress the powerful ionosphere clutter with a multisegment estimation and suppression scheme. About 15–23 dB signal to interference ratio (SIR) improvement can be excepted when using the proposed method, whereas the targets can be more easily detected in the range-Doppler map. Experimental results demonstrate that the scheme proposed is effective for nonstationary ionosphere clutter and is proven to be a practical interference cancellation technique for HFSWR.

A SOLUTION TO STABILIZE THE RECEIVER BEAMWIDTH WHEN CHANGING THE OPERATING FREQUENCY OF HIGH-FREQUENCY SURFACE WAVE RADAR

2021 ◽  
pp. 2614-2624
Author(s):  
H. H. Dung, C. V. Linh
Keyword(s):  
Signal Processing ◽  
Surface Wave ◽  
Frequency Modulation ◽  
High Frequency ◽  
Operating Frequency ◽  
Design Solution ◽  
Processing Quality ◽  
Wave Radar ◽  
Single Station ◽  
Interference Frequency

A single-station High-Frequency Surface Wave Radar (HFSRR) consists of transmitting and receiving antennas in an area with a distance between them approximately ten times their wavelength. At the coast, these antennas are usually deployed at fixed optimal distances for an operating frequency in the HF band (3÷30Mhz). Because the signal used is linear frequency modulation (FMCW), the HFSWS always requires an interference-resistant frequency band. So, it is necessary to change the operating frequency in HFSWR to avoid strong interference, frequency bands. This also results in a change in the received waveform, which affects signal processing quality. In this article, a design solution is proposed to maintain a consistent beamwidth when changing the operating frequency in the HFSWS.

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