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

Remote Sensing

Chengxi Shen²  Weimin Huang²  Eric W. Gill²  Ruben Carrasco³  Jochen Horstmann³  Wolfgang Wagner¹ 

[1] Department of Electrical and Computer Engineering, Memorial University, St. John’s, NF A1B 3X5, Canada;;Department of Electrical and Computer Engineering, Memorial University, St. John’s, NF A1B 3X5, Canada; E-Mails:;Centre for Materials and Coastal Research, Helmholtz-Zentrum Geesthacht, Max-Planck Strasse 1, D-21502 Geesthacht, Germany; E-Mails:

关键词: marine radar;    surface current;    remote sensing;   

DOI  :  10.3390/rs70607753

来源: mdpi

【 摘 要 】

In this paper, a novel current inversion algorithm from X-band marine radar images is proposed. The routine, for which deep water is assumed, begins with 3-D FFT of the radar image sequence, followed by the extraction of the dispersion shell from the 3-D image spectrum. Next, the dispersion shell is converted to a polar current shell (PCS) using a polar coordinate transformation. After removing outliers along each radial direction of the PCS, a robust sinusoidal curve fitting is applied to the data points along each circumferential direction of the PCS. The angle corresponding to the maximum of the estimated sinusoid function is determined to be the current direction, and the amplitude of this sinusoidal function is the current speed. For validation, the algorithm is tested against both simulated radar images and field data collected by a vertically-polarized X-band system and ground-truthed with measurements from an acoustic Doppler current profiler (ADCP). From the field data, it is observed that when the current speed is less than 0.5 m/s, the root mean square differences between the radar-derived and the ADCP-measured current speed and direction are 7.3 cm/s and 32.7°, respectively. The results indicate that the proposed procedure, unlike most existing current inversion schemes, is not susceptible to high current speeds and circumvents the need to consider aliasing. Meanwhile, the relatively low computational cost makes it an excellent choice in practical marine applications.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland