scholarly journals The Vertical Ionosphere Parameters Inversion for High Frequency Surface Wave Radar

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Xuguang Yang ◽  
Changjun Yu ◽  
Aijun Liu ◽  
Linwei Wang ◽  
Taifan Quan
Keyword(s):  
Surface Wave ◽  
High Frequency ◽  
Plasma Frequency ◽  
Hot Spot ◽  
Research Area ◽  
F Region ◽  
Wave Radar ◽  
Parameters Inversion ◽  
Radar Equation ◽  
Field Aligned Irregularities

High Frequency Surface Wave Radar (HFSWR), which is currently applied in over-the-horizon detection of targets and sea states remote sensing, can receive a huge mass of ionospheric echoes, making it possible for the ionospheric clutter suppression to become a hot spot in research area. In this paper, from another perspective, we take the ionospheric echoes as the signal source rather than clutters, which provides the possibility of extracting information regarding the ionosphere region and explores a new application field for HFSWR. Primarily, pretreatment of threshold segmentation as well as connected region generation is used in the Range-Doppler (R-D) Spectrum to extract the ionospheric echoes. Then, electron density and plasma frequency of field aligned irregularities (FAIs) caused by plasma instabilities in the F region are obtained by the coherent backscattered radar equation. The plasma drift velocity of FAIs can also be estimated from Doppler shift. Ultimately, the effectiveness of inversion is verified by comparing with IRI2012.

scholarly journals Azimuth Resolution Improvement and Target Parameters Inversion for Distributed Shipborne High Frequency Hybrid Sky-Surface Wave Radar

2021 ◽  
Vol 13 (13) ◽  
pp. 2471
Author(s):  
Mingkai Ding ◽  
Peng Tong ◽  
Yinsheng Wei ◽  
Lei Yu
Keyword(s):  
Surface Wave ◽  
High Frequency ◽  
Velocity Vector ◽  
Target Velocity ◽  
Moving Target ◽  
Signal Model ◽  
Wave Radar ◽  
Resolution Improvement ◽  
Parameters Inversion ◽  
Azimuth Resolution

In this paper, the aperture synthesis processing techniques for the distributed shipborne high frequency hybrid sky-surface wave radar (HFHSSWR) are proposed to improve the azimuth resolution and obtain the velocity vector and the azimuth estimation of the moving target. First, the system geometry and the signal model of the moving target for the distributed shipborne HFHSSWR are formulated, and then the azimuth resolution improvement principle is derived. Second, based on the developed signal model, we propose an azimuth resolution improvement algorithm, which can obtain the synthetic azimuth bandwidth and an improved resolution using sub-band combination. Finally, a target parameters inversion method is introduced to estimate the target velocity vector and the target azimuth, by solving the equations regarding the target geometry and echo signal parameters numerically. The simulations are performed to verify the proposed algorithms. The results indicate that the distributed synthetic aperture techniques effectively improve the azimuth resolution of this radar, and can obtain the target velocity vector and the high-precision estimation of the target azimuth.

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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