Sea-State Monitoring Via X-Band Marine Radar Images Sequences: A New Approach for an Accurate Surface Currents Estimation

2009 ◽  
Author(s):  
Francesco Serafino ◽  
Claudio Lugni ◽  
Francesco Soldovieri
Keyword(s):  
Synthetic Data ◽  
Surface Current ◽  
Key Factors ◽  
State Monitoring ◽  
Sea State ◽  
Reconstruction Procedure ◽  
Factors Affecting ◽  
Radar Images ◽  
X Band ◽  
Marine Radar

This work deals with the sea state monitoring starting from marine radar images collected on a moving ship. For such a topic, one of the key factors affecting the reliability of the reconstruction procedure is the determination of the equivalent surface current that also accounts for the speed of the moving ship. Here, we propose a method able to evaluate also high values of the sea surface current. The reliability of the proposed procedure is shown by a numerical analysis with synthetic data. Finally, we present some preliminary results with measurements collected on a moving ship.

scholarly journals X-Band Radar for the Monitoring of Sea Waves and Currents: A Comparison between Medium and Short Radar Pulses

2017 ◽  
Author(s):  
Giovanni Ludeno ◽  
Francesco Raffa ◽  
Francesco Soldovieri ◽  
Francesco Serafino
Keyword(s):  
Surface Current ◽  
Parameters Estimation ◽  
Sea Waves ◽  
State Monitoring ◽  
Sea State ◽  
Experimental Campaign ◽  
X Band ◽  
Waves And Currents ◽  
Marine Radar ◽  
Good Agreement

Abstract. This letter presents the monitoring results of the sea waves and the surface currents obtained by analyzing data acquired by a X-band marine radar in two different operative conditions, namely the short and medium pulse modes. In particular, we investigated the feasibility to use a medium radar pulse for sea state monitoring by comparing the performance in both the radar modes. The comparison was carried out by means of an experimental campaign and we observed a good agreement for surface current and sea state parameters estimation.

scholarly journals Estimation of the Significant Wave Height from Marine Radar Images without External Reference

2019 ◽  
Vol 7 (12) ◽  
pp. 432 ◽  
Author(s):  
Ludeno ◽  
Serafino
Keyword(s):  
Wave Height ◽  
Significant Wave Height ◽  
State Monitoring ◽  
Sea State ◽  
Significant Wave ◽  
Radar Images ◽  
External Reference ◽  
Challenging Tasks ◽  
In Situ Sensors ◽  
Marine Radar

In the context of the sea state monitoring by means of the X-band marine radar, the estimation of a significant wave height (Hs) is, currently, one of the most challenging tasks. For its estimation, a calibration is usually required using an external reference, such as in situ sensors, and mainly buoys. In this paper, a method that allows us to avoid the need for an external reference for Hs estimation is presented. This strategy is, mainly, based on the correlation between a raw radar image and the corresponding non-calibrated wave elevation image to which varying its amplitude by using a scale factor creates a mathematical model for the radar imaging. The proposed strategy has been validated by considering a simulated waves field, generated at varying sea state conditions. The results show a good estimation of the significant wave height, confirmed by a squared correlation coefficient greater than 0.70 for each considered sea state.

scholarly journals Estimation of Sea Surface Current from X-Band Marine Radar Images by Cross-Spectrum Analysis

2019 ◽  
Vol 11 (9) ◽  
pp. 1031 ◽  
Author(s):  
Zhongbiao Chen ◽  
Biao Zhang ◽  
Vladimir Kudryavtsev ◽  
Yijun He ◽  
Xiaoqing Chu
Keyword(s):  
Current Velocity ◽  
Wave Spectrum ◽  
Surface Current ◽  
Least Square ◽  
Spectral Approach ◽  
Spectral Correlation ◽  
Radar Images ◽  
X Band ◽  
Marine Radar ◽  
The Cross

The cross-spectral correlation approach has been used to estimate the wave spectrum from optical and radar images. This work aims to improve the cross-spectral approach to derive current velocity from the X-band marine radar image sequence, and evaluate the application conditions of the method. To reduce the dependency of gray levels on range and azimuth, radar images are preprocessed by the contrast-limited adaptive histogram equalization. Two-dimensional cross-spectral coherence and phase are derived from neighboring X-band marine radar images, and the phases with large coherences are used to estimate the phase velocity and angular frequency of waves, which are first fitted with the theoretical dispersion relation by different least square models, and then the current velocity can be determined. Compared with the current velocities measured by a current meter, the root-mean-square error, correlation coefficient, bias, and relative error are 0.15 m/s. 0.88, –0.05 m/s, and 7.79% for the north-south velocity, and 0.14 m/s, 0.86, 0.06 m/s, and 10.75% for the east-west velocity in the experimental area, respectively. The preprocessing, critical coherence, and the number of images for applying the cross-spectral approach, are discussed.

scholarly journals An Algorithm for Surface Current Retrieval from X-band Marine Radar Images

2015 ◽  
Vol 7 (6) ◽  
pp. 7753-7767 ◽  
Author(s):  
Chengxi Shen ◽  
Weimin Huang ◽  
Eric Gill ◽  
Ruben Carrasco ◽  
Jochen Horstmann
Keyword(s):  
Surface Current ◽  
Radar Images ◽  
X Band ◽  
Marine Radar

REMOCEAN: A Flexible X-Band Radar System for Sea-State Monitoring and Surface Current Estimation

2012 ◽  
Vol 9 (5) ◽  
pp. 822-826 ◽  
Author(s):  
F. Serafino ◽  
C. Lugni ◽  
G. Ludeno ◽  
D. Arturi ◽  
M. Uttieri ◽  
...  
Keyword(s):  
Surface Current ◽  
Radar System ◽  
State Monitoring ◽  
Sea State ◽  
Current Estimation ◽  
X Band

scholarly journals Sea surface topography reconstruction from X-band radar images

2008 ◽  
Vol 19 ◽  
pp. 83-86 ◽  
Author(s):  
F. Serafino ◽  
C. Lugni ◽  
F. Soldovieri
Keyword(s):  
Sea Surface ◽  
State Monitoring ◽  
Sea State ◽  
Radar Images ◽  
Sea Surface Topography ◽  
X Band ◽  
Sea Current ◽  
Global Vision ◽  
Inversion Procedure

Abstract. The paper deals with the feasibility study of the sea state monitoring starting from X-band radar images. The exploitation of radar images allows to achieve a global vision of the sea state compared to the local vision given by the usual sensors as the buoys. The processing approach is based on the formulation of problem as an inverse one where starting from the electromagnetic field backscattered by the sea surface, the information about the sea state are retrieved. The reliability of the inversion procedure is shown by processing synthetic and experimental data where particular attention is focussed to the determination of the sea current and speed of the vessel.

Towards Nonlinear Wave Reconstruction and Prediction From Synthetic Radar Images

2016 ◽  
Author(s):  
A. P. Wijaya
Keyword(s):  
Vertical Direction ◽  
Sea Surface ◽  
Sea State ◽  
Operational Effectiveness ◽  
State Reconstruction ◽  
Radar Images ◽  
First Results ◽  
Marine Radar ◽  
Offshore Activities

The use of remotely wave sensing by a marine radar is increasingly needed to provide wave information for the sake of safety and operational effectiveness in many offshore activities. Reconstruction of radar images needs to be carried out since radar images are a poor representation of the sea surface elevation: effects like shadowing and tilt determine the backscattered intensity of the images. In [1], the sea state reconstruction and wave propagation to the radar has been tackled successfully for synthetic radar images of linear seas, except for a scaling in the vertical direction. The determination of the significant wave height from the shadowed images only has been described in [2]. This paper will summarize these methods, and provides the first results for the extension to nonlinear seas.

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