Ocean Surface Current Measurement Using Shipborne HF Radar: Model and Analysis

Chang, Guanghong; Li, Ming; Xie, Junhao; Zhang, Ling; Yu, Changjun; Ji, Yonggang

doi:10.1109/joe.2016.2527938

Cited by 35 publications

(12 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Compared with the conventional method based on a land-based receiving array, this method was stated to be more easily realized with less system cost. Similarly, methods for ocean surface current extraction and ocean clutter spectrum estimation for shipborne HFSWR were developed in [26][27][28].…”

Section: Radar Cross Section Models For An Antenna On a Floating Platmentioning

confidence: 99%

First‐order bistatic high‐frequency radar ocean surface cross‐section for an antenna on a floating platform

Gill

Huang

2016

IET Radar, Sonar & Navigation

View full text Add to dashboard Cite

Land-based high frequency surface wave radar (HFSWR) is an established sensor for ocean remote sensing. Placing an HFSWR on a floating platform has the advantage of mobility. However, antenna motion will distort the Doppler spectrum, which is used to extract ocean information and to detect the signatures of targets. In this thesis, significant effort has been expended on establishing radar cross section (RCS) models for a fixed receiver and a transmitter on a floating platform, analyzing the effect of the antenna motion, and developing a motion compensation method to eliminate the effect of the platform motion. The first-and second-order monostatic RCSs of the ocean surface for the case of a pulsed dipole source on a floating platform have been previously derived in the literature, with the assumption that the platform motion is a single-frequency sinusoid. Following that work, the research in this thesis is extended to the bistatic case. The effect of platform motion on simulated Doppler spectra is considered for a variety of sea states. It is shown that the resulting motion-induced peaks are symmetrically distributed in the Doppler spectrum. Following this work, the corresponding bistatic RCS models for a frequency modulated continuous waveform (FMCW) source are derived. Results show that the sidelobe level for an FMCW source is reduced with increasing extent of range bin. To mimic real world scenarios, platform motion is next modelled as a combination of two cosine functions, based on existing research of realistic horizontal motions of moored floating platforms. RCSs incorporating a dual-frequency platform motion model are then developed. These can be extended to a general form incorporating a multi-frequency platform motion. It is found that the platform motion can be viewed as a modulator of the radar frequencies, with the modulation indices related to the amplitudes of the platform motion. ii Finally, to mitigate the effect of platform motion on the Doppler spectra, a motion compensation method is proposed. This motion compensation method can be achieved by a deconvolution process. Calculations involving a RCS model, incorporating external noise, for an antenna on a floating platform are conducted in order to simulate field data and to examine this motion compensation method. The external noise is characterized as a white Gaussian zero-mean process. By using this newly-developed RCS model with external noise, motion compensation results under different sea states and signal-to-noise ratios (SNRs) are examined. The outcomes indicate that an iterative Tikhonov regularized deconvolution technique is superior to other compensation methods implemented in this study. iii Four years of PhD life has been a challenging journey to me, one filled with joy, sadness, excitement, and sometimes depression and confusion. At the end of my PhD, I would like to show my sincere gratitude to all of you for accompanying and helping me in my PhD journey. Foremost, I would like to express my deepest gratitude to my supervisors, D...

show abstract

Section: Radar Cross Section Models For An Antenna On a Floating Platmentioning

confidence: 99%

First‐order bistatic high‐frequency radar ocean surface cross‐section for an antenna on a floating platform

Gill

Huang

2016

IET Radar, Sonar & Navigation

View full text Add to dashboard Cite

show abstract

“…The orbital velocity of the long waves is modeled as the function of time t and slant range r and can be written as Xin et al [3]: As shown in Figure 4, the orbital velocity of the long waves is time-varying and space-varying, the wave profile is the linear superposition of sinusoidal waves, and the orbital velocity of the long waves possesses the periodicity shown in Figure 4 [3,33]. The orbital velocity of the long waves is modeled as the function of time t and slant range r and can be written as Xin et al [3]: (8) where N w is the number of harmonic waves, A i is the amplitude of the ith harmonic sinusoidal wave, ω i is the angular velocity of the ith sinusoidal wave and k i is the wavenumber of the ith wave.…”

Section: Doppler Shift Of the Orbital Motions Of The Long Wavesmentioning

confidence: 99%

“…The Bragg scattering theory specifies that the radar is primarily sensitive to radially-traveling waves that satisfy the Bragg resonant condition, and the phase velocity of the Bragg resonant waves is also stable. Therefore, the high-frequency (HF) ocean surface current radar can measure the sea surface current velocity utilizing the Bragg scattering theory of the sea surface [5][6][7][8] and can be applied to estimate the sea surface current velocity of large areas; for example, the shore-based HF ocean surface current radar of the University of Miami has been used to measure the 2-D offshore surface current vectors from …”

Section: Introductionmentioning

confidence: 99%

Sea Surface Current Estimation Using Airborne Circular Scanning SAR with a Medium Grazing Angle

et al. 2018

View full text Add to dashboard Cite

Circular scanning synthetic aperture radar (SAR) is a novel imaging mode wherein the radar antenna rotates from 0 degrees to 360 degrees along the platform flight direction, providing us with a potentially effective technique to estimate the sea surface current velocity. In this paper, we propose a novel method to estimate the sea surface current velocity utilizing the Doppler centroid shifts of different scan angles over 360 degrees after the airborne platform motion compensation. In this method, the Doppler centroid shifts of the sea clutter at different scan angles are first extracted, and the corresponding compensation errors caused by the azimuth pointing and the incidence angle of the radar beam are considered. Finally, the least squares (LS) technique is applied to estimate the along-track velocity component and the cross-track velocity component of the sea surface current. The effectiveness of the proposed method is verified by the real data recorded by an airborne circular scanning SAR system.

show abstract

“…In the previous works, however, the hull itself is either stationary or moving at a low speed without considering a high-speed case and effects of six DOFs motion on radar Doppler spectra. In this section, the potential of remote sensing of ocean surface radial current with shipborne HFSWR is presented [24]. Moreover, a stream function method is introduced to obtain current vector field using an improved music signal classification (MUSIC) algorithm and unitary transformation technique [25].…”

Section: Remote Sensing Of Ocean Surface Current With Shipborne Hfswrmentioning

confidence: 99%

Remote Sensing with Shipborne High-Frequency Surface-Wave Radar

Xie¹,

Sun²,

Ji³

et al. 2018

Recent Advances and Applications in Remote Sensing

Self Cite

View full text Add to dashboard Cite

High-frequency surface-wave radar (HFSWR) has been successfully applied for moving target detection and remote sensing of ocean surface dynamic parameters for decades. Compared with conventional instruments such as buoys, anemometers, and microwave radars, HFSWR can be employed to an all-weather and all-time surveillance far beyond the visible horizon. Moreover, based on agility and maneuverability, shipborne HFSWR can not only enhance the survivability in complex ocean environment but also enlarge the detection distance on open sea, which will gradually become a popular deployment situation. In this chapter, ocean surface cross sections for shipborne HFSWR with linear platform motion and sway motion are derived theoretically. Then, the methods for ocean surface wind direction, wind field, and current extraction are presented. The computer simulations and experimental results of the real data are given to verify the detection accuracy and the distance limit of the abovementioned methods.

show abstract

Ocean Surface Current Measurement Using Shipborne HF Radar: Model and Analysis

Cited by 35 publications

References 27 publications

First‐order bistatic high‐frequency radar ocean surface cross‐section for an antenna on a floating platform

First‐order bistatic high‐frequency radar ocean surface cross‐section for an antenna on a floating platform

Sea Surface Current Estimation Using Airborne Circular Scanning SAR with a Medium Grazing Angle

Remote Sensing with Shipborne High-Frequency Surface-Wave Radar

Contact Info

Product

Resources

About