TY  - JOUR
T1  - Ocean Surface Currents Determination from X-Band Radar Image Sequences
AU - Ramakrishna, I.V.S. 
JO  - Journal of Engineering and Applied Sciences
VL  - 12
IS  - 24
SP  - 7486
EP  - 7488
PY  - 2017
DA  - 2001/08/19
SN  - 1816-949x
DO  - jeasci.2017.7486.7488
UR  - https://makhillpublications.co/view-article.php?doi=jeasci.2017.7486.7488
KW  - Currents
KW  -validation
KW  -accuracy
KW  -instrumentation
KW  -image
KW  -India
AB  - An algorithm for retrieving ocean surface currents using nautical radar-image sequences is presented
in this study. The image sequences are acquired by common marine X-band radar. With the Fast Fourier
transformation the image sequences are transformed to the wave number frequency domain and produce a three
dimensional image power spectrum. In the absence of the sensor’s velocity and the near surface current the
spectral energy in this three-dimensional wave number frequency space will lie on a shell defined by the
dispersion relationship. Any deviation from the expected dispersion relationship can be interpreted as a current
induced Doppler shift of the wave frequency. A weighted least squares curve fitting technique is used to
determine the surface current. For validation of the algorithm, the surface current derived from the inverted radar
data sets and from ground truth data are compared. It is shown that, the radar-retrieved surface currents are
within the accuracy of the conventional instrumentation.
ER  -