THE VERIFICATION OF 2-D WAVE PARAMETER 
FROM MARINE RADAR BY IN SITU MEASUREMENT 
Shintaro Goto, Kiyonori Iisawa, and Masaaki Shikada 
Kanazawa Institute of Technology 
7-1 Ohgigaoka Nonoichi Ishikawa 921, Japan 
Tel: +81-762-94-6710, Fax: +81-762-94-6711 
E-mail: got@ Gaia.manage.kanazawa-it.ac.jp 
Commission VII, Working Group 8 
KEY WORDS: MARINE RADAR, MICROW AVE REMOTE SENSING, WAVE DIRECTION, 
COASTAL ENGINEERING 
ABSTRACT 
The objective of this study is validation of 2-D wave parameter from marine radar by comparing in 
situ measurement. 
Before the marine radar is calibrated by comparing in situ data. Firstly we proposed the method for 
monitoring 2-D wave parameter, especially wave length and wave direction, by using simulated 
image of marine radar. The accuracy of the proposed method in this study is concluded over 90%. 
Secondary we observed the wave parameter around the coast area near Komatsu city besides Sea of 
Japan by marine radar from Jan.5 to Jan.6, 1995 when the highest significant wave in winter of 
1995's was observed. From Image of marine radar we obtained the wave direction and wave length. 
These two parameter was calibrated by in situ data by Ministry of Construction Japan. 
The Accuracy of wave direction fits to the in situ data. But the accuracy of wave frequency is lower 
than wave direction. The error depends on the reason that we use small amplitude wave theory on 
translating from spatial frequency monitored by marine radar to time series frequency. Translation 
from spatial frequency to special frequency is a big problem on wave theory. Making allowance for 
the reason mentioned above,we find that it is accurate enough for operational use. 
1. INTRODUCTION the ERS-1 SAR wave mode operation by using 
F. Ziemer etal's method. Buttheir application 
  
The Observation of two dimensional (2-D) wave 
parameter distribution is important for the 
estimation of the wave force to marine 
constructions, such as jetty. The in situ data 
routinely observed now are point data and the 
cost is expensive, so the number of observation 
point is a few. There is no routine method for 
monitoring 2-D wave parameter distribution. 
Marine radar can offer the image of 2-D wave 
field by monitoring the sea clutter from the sea 
surface.  FZiemer,and W.Rosenthal P Was 
developed the transfer function for marine radar 
for imaging ocean waves. After applying the 
transfer function to the image spectra, significant 
wave heights were estimated and compared with 
results from other sensors during LEWEX ^". 
Results of their study are very promising. 
M.D.Henschel, Robert A. Paul, and B.M.Eid>) 
developed the prototype marine radar ocean wave 
imaging system, MACRADAR, for validation of 
252 
was carried out only on the offshore region. 
In this study we use the marine radar in near 
shore region for verification 2-D wave parameter 
by using in situ data. 
2.DATA ANALYSIS METHOD 
Fig.1 shows the flow diagram of analysis 
procedure. As the received power from the sea 
surface become more and more weakly as the 
radar is far from the radar site. The correction 
function are applied to correct the difference of 
these power due to the distance from the radar to 
the sea surface. And the received power from the 
radar is PPI image shown as Fig.2 on polar 
coordinate system, so the image 1s transformed 
to x-y coordinate system for FFT analysis.The 
Fourier transformation F(kx,ky) is defined by 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B7. Vienna 1996 
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