Yiming Wang

Harbin Institute of Technology | HIT · School of Electronic and Information Engineering

Doppler frequencies generated by the navigating ship targets may coincide with the first order Doppler spectrum of the sea clutter in high frequency surface wave radar (HFSWR). Therefore, the ship targets fall in this clutter spectrum were usually undetectable by the traditional processing method in HFSWR. In this paper, we introduced a spatial bli...

Traditional approaches for interference suppression will enjoy the added benefits when more domains are involved in antenna array. However, the information from range domain and its collaboration with other domains are rarely explored, and their potentials in improvement of radar performance are under-estimated. In this paper, we introduce the conc...

Shipborne High-Frequency Surface Wave Radar (HFSWR) can receive vessel target signals from both the left and right sides of the shipborne platform, resulting in the ambiguity phenomenon of vessel target azimuth and uncertainty of target spatial positioning. This paper proposes a method to eliminate the ambiguity of target azimuth by utilizing the d...

Compared to shore-based High-Frequency Surface Wave Radar (HFSWR), shipborne HFSWR can overcome the constraints of a fixed radar site and extend its detection range. However, the radar echo is influenced by the movement of the shipborne platform, which in turn affects the target monitoring performance of the shipborne HFSWR. In this paper, the rada...

The echo from shipborne High Frequency Surface Wave Radar (HFSWR) is significantly influenced by the movement of the shipborne platform, and the accurate estimation of antenna displacement on the shipborne platform is a key factor in reflecting the echo model for shipborne HFSWR. However, the existing echo models for shipborne HFSWR mainly use idea...

Due to its maneuverability and agility, the shipborne high-frequency surface wave radar (HFSWR) provides a new way of monitoring large-area marine dynamics and environment information. However, wind direction ambiguity is problematic when using monostatic shipborne HFSWR for wind direction inversion. In this article, an unambiguous wind direction m...

Coast-transmit ship-receive (CTSR) bistatic high-frequency surface wave radar (HFSWR) can fully exploit the flexibility of moving platform and the anti-interference advantages of bistatic radar. However, the platform motion can cause the spread of target echo in the frequency spectrum and reduction of amplitude, which is not conducive to detection....

Shipborne high-frequency surface wave radar (HFSWR) has wide-area coverage capability and maneuverability compared to shore-based HFSWR systems. Due to the influence of platform motion, especially yaw motion, the traditional detection-before-tracking method (TBD) based on channel Range-Doppler-Time (RDT) becomes ineffective, resulting in track frag...

A bistatic high-frequency surface wave radar (HFSWR) with both receiving and transmitting stations placed on different ships (platforms) is a new radar system and referred to as shipborne bistatic HFSWR. In this paper, a first-order ocean surface cross section of shipborne bistatic HFSWR was derived. The first-order cross-section models for three d...

High-frequency surface wave radar (HFSWR) can detect and continuously track ship targets in real time and beyond the horizon. Compared with transmit/receive (T/R) monostatic HFSWR, the T-R bistatic HFSWR has the advantages of flexibility, receiver concealment and large coverage because of the separation between the radar transmitter and receiver lo...

For shipborne high-frequency surface wave radar (HFSWR), the movement of the ship has a great impact on the radar echo, thus affecting target detection performance. In this paper, the characteristics of the target echo spectrum and the motion compensation methods for shipborne HFSWR are investigated. Firstly, simulation analysis of echo from a movi...

The coast–ship bistatic high-frequency surface wave radar (HFSWR) not only has the anti-interference advantages of the coast-based bistatic HFSWR, but also has the advantages of maneuverability and an extended detection area of the shipborne HFSWR. In this paper, theoretical formulas were derived for the coast–ship bistatic radar, including the fir...

In this study, based on the shipborne high-frequency (HF) surface wave radar target detection application, the first-order ocean surface cross-section for the shipborne HF surface wave radar is simulated, and the relationship between the sea clutter widening characteristics and platform speed is analysed. Then, the relationship between the target e...

For a polarization sensitive array (PSA) composed of electromagnetic vector sensors (EMVSs), all component-antennas of an EMVS are spatially collocated at a same location in the PSA, and mutual coupling introduced has an adverse effect on parameter estimation. The mutual coupling is not only among antennas in adjacent elements, namely, inter-elemen...

For multiple-input multiple-output (MIMO) radar employing the advantage of virtual array, the general assumption of the perfect orthogonality between multiple waveforms is proved to be unachievable. Therefore, to achieve good orthog-onality, transmission schemes employing frequency diversity or chirp modulation diversity have been extensively inves...

For multiple-input multiple-output (MIMO) radar employing the advantage of virtual array, the general assumption of the perfect orthogonality between multiple waveforms is proved to be unachievable. Therefore, to achieve good orthogonality, transmission schemes employing frequency diversity or chirp modulation diversity have been extensively invest...

High-frequency surface wave radar (HFSWR) can detect and continuously track vessels beyond the horizon in excess of 200 nautical miles from the array [1]–[3]. Moreover, multiple HFSWRs can be used, and their detection results can be fused to improve the detection performance of marine target [13]–[15]. Most current HFSWRs for ship surveillance are...

We develop an experiment to obtain the sea state parameters using HF surface-wave radar (HFSWR) and the in situ instruments. The wind direction is extracted, and the results are compared with the in situ data. In addition, the wind direction ambiguity was eliminated by the maximum likelihood (ML) method. The results from the radar are compared with...

The detection of vessel targets could be effectively resolved in a high-frequency surface wave radar (HFSWR). However, signals reflected from vessels are concealed by sea clutter in the Doppler spectrum, where such detections are performed. Consequently, differences between these features in the Doppler domain cannot be readily observed, which grea...

High-frequency hybrid sky–surface wave radar (HFHSSWR) is a new remote sensing instrument with potential for applicability to largearea sea state monitoring. This study investigated the use of HFHSSWR for ocean surface current measurements. Based on the Doppler shift of the first-order Bragg peak of HFHSSWR, the component of the Doppler shift cause...

Based on sparse representations, the problem of two-dimensional (2-D) direction of arrival (DOA) estimation is addressed in this paper. A novel sparse 2-D DOA estimation method, called Dimension Reduction Sparse Reconstruction (DRSR), is proposed with pairing by Spatial Spectrum Reconstruction of Sub-Dictionary (SSRSD). By utilizing the angle decou...

High-frequency surface wave radar (HFSWR) is employed generally to detect and track moving targets by using the Doppler shift of target echoes caused by their radial movement relative to the radar site. As the target echoes with zero-Doppler are often mistaken for land or islands clutter, they would be discarded or removed as clutters in most cases...

High-frequency surface wave radars (HFSWRs) have been used to monitor moving vessel targets within large areas of the coastal ocean. Moreover, a dual-frequency HFSWR can overcome the negative effect of sea clutter on vessel target detection. As only the information of point targets are used in the traditional point association method of dual-freque...

The characteristics of frequency shift and broadening of first-order sea clutter for High Frequency Hybrid Sky-Surface Wave Radar (HFHSSWR) make it harder to isolate the first-order sea clutter spectrum than that of High Frequency Surface Wave Radar (HFSWR). In this paper, the characteristics of first-order sea clutter for HFHSSWR are investigated,...

The Barrick's model of significant wave height inversion is a relatively practical model for the high-frequency surface wave radar (HFSWR) sea echoes. For improving the inversion accuracy of the significant wave height, a three-parameter model is proposed, in which a modulation parameter is added to improve the degree of fitting. The significant wa...

To develop a NaI (Tl) detector for in situ radioactivity monitoring in the marine environment and enhance the confidence of the probability of the gamma-spectrum analysis, Monte Carlo simulations using the Monte Carlo N-Particle ( MNCP ) code were performed to provide the response spectra of some interested radionuclides and the background spectra...

The information of the significant wave height is needed in the wind speed inversion from the sea echo of High Frequency Surface Wave Radar (HFSWR) by using the empirical model of wind waves. Therefore, the accuracy of the significant wave height has an effect on the wind speed inversion. Based on the empirical model of wind waves, a wind speed inv...

A generalized oblique projection (GOP) with an adjustable parameter defined as interference suppression cost (ISC) is proposed. Therefore, an optional optimized signal to interference-plus-noise ratio (SINR) and user controlled actions on the interference filtering are presented in this GOP framework. Theoretical analysis and numerical simulation d...

In this paper, three algorithms are applied to extract the wind direction using a month HFSWR data in an experiment with a single radar system. The preliminary results show that the three algorithms can all eliminate the ambiguity of the wind direction. And the RMS error (RMSE) obtained by the angle comparison multi-beam (ACMB) algorithm is 24.80°,...

A space-borne synthetic aperture radar (SAR), a high frequency surface wave radar (HFSWR), and a ship automatic identification system (AIS) are the main remote sensors for vessel monitoring in a wide range. These three sensors have their own advantages and weaknesses, and they can complement each other in some situations. So it would improve the ca...

Maritime ship targets detection with high frequency (HF) surface wave radar (HFSWR) of single frequency can be affected by the first-order sea clutter and HF resonant zone target echo intensity fluctuation and cause the target undetected cases. Based on the measured HFSWR data, the characteristics of dual-frequency HFSWR on ship detection and the i...

The ocean current affection on the posture of two type of submerged buoy is analyzed through FEM analysis. By comparing the factors of impact pressure coefficient distribution, ocean current speed distribution, impact pressure force in horizontal direction and vertical direction, Turbulence Kinetic Energy distribution and vortex generation, the adv...

Aloha or later slotted Aloha is known as the first protocol for packet radio network and a classic example of random access protocol. However, their performance is not promising as they can only achieve maximum throughput of 18% and 36% for Aloha and slotted Aloha, respectively. Moreover it will be unstable for increasing traffic. An improvement pr...