Directional Wave Spectra from Video Images Data and SWAN Model

2015 ◽  
Vol 74 (5) ◽  
Author(s):  
Muhammad Zikra ◽  
Noriaki Hashimoto ◽  
Masaru Yamashiro ◽  
Kojiro Suzuki
Keyword(s):  
Shallow Water ◽  
Water Area ◽  
Paper Analysis ◽  
Wave Spectra ◽  
Swan Model ◽  
Video Images ◽  
Shallow Water Area ◽  
Directional Wave ◽  
Probe Sensor ◽  
Rectification Process

In this paper, analysis of directional wave spectra in shallow water area estimated by video images data has been compared with numerical model of SWAN. Estimation of directional wave spectra from video images is based on the Bayesian Directional Method using a group of pixels brightness on the image. For this study, the pixels can be considered equivalent to fixed instruments as wave probe sensor after rectification process. The results show that there is a good agreement between directional wave spectra estimated by video images data and the SWAN model. Both methods estimate similar shape of directional wave spectra in the shallow water. In addition, the energy distribution of directional wave spectra in shallow water is concentrated significantly in frequency and direction. 

Time variability of acoustic signals in a benign shallow‐water area

2000 ◽  
Vol 108 (5) ◽  
pp. 2578-2578
Author(s):  
Peter L. Nielsen ◽  
Martin Siderius ◽  
Finn B. Jensen
Keyword(s):  
Shallow Water ◽  
Acoustic Signals ◽  
Water Area ◽  
Time Variability ◽  
Shallow Water Area

scholarly journals ANALYIS OF WAVE SPECTRA FOR SHALLOW WATER WAVES USING VIDEO IMAGES TECHNIQUE

2011 ◽  
Vol 67 (2) ◽  
pp. I_943-I_948
Author(s):  
Muhammad ZIKRA ◽  
Noriaki HASHIMOTO ◽  
Masaki YOKOTA ◽  
Masaru YAMASHIRO ◽  
Kojiro SUZUKI
Keyword(s):  
Shallow Water ◽  
Water Waves ◽  
Wave Spectra ◽  
Shallow Water Waves ◽  
Video Images

scholarly journals SATELLITE-DERIVED BATHYMETRY: ACCURACY ASSESSMENT ON DEPTHS DERIVATION ALGORITHM FOR SHALLOW WATER AREA

2017 ◽  
Vol XLII-4/W5 ◽  
pp. 159-164 ◽  
Author(s):  
N. M. Said ◽  
M. R. Mahmud ◽  
R. C. Hasan
Keyword(s):  
Shallow Water ◽  
Accuracy Assessment ◽  
Water Area ◽  
Bathymetric Data ◽  
Sensing Technology ◽  
Shallow Water Area ◽  
Multispectral Satellite Imagery ◽  
Marginal Improvement ◽  
Acquisition Technique ◽  
Hydrographic Surveying

Over the years, the acquisition technique of bathymetric data has evolved from a shipborne platform to airborne and presently, utilising space-borne acquisition. The extensive development of remote sensing technology has brought in the new revolution to the hydrographic surveying. Satellite-Derived Bathymetry (SDB), a space-borne acquisition technique which derives bathymetric data from high-resolution multispectral satellite imagery for various purposes recently considered as a new promising technology in the hydrographic surveying industry. Inspiring by this latest developments, a comprehensive study was initiated by National Hydrographic Centre (NHC) and Universiti Teknologi Malaysia (UTM) to analyse SDB as a means for shallow water area acquisition. By adopting additional adjustment in calibration stage, a marginal improvement discovered on the outcomes from both Stumpf and Lyzenga algorithms where the RMSE values for the derived (predicted) depths were 1.432 meters and 1.728 meters respectively. This paper would deliberate in detail the findings from the study especially on the accuracy level and practicality of SDB over the tropical environmental setting in Malaysia.

scholarly journals WIND AND WAVE RELATIONSHIPS IN A SHALLOW WATER AREA

1974 ◽  
Vol 1 (14) ◽  
pp. 6
Author(s):  
J.S. Driver ◽  
J.D. Pitt
Keyword(s):  
Shallow Water ◽  
Water Area ◽  
Extreme Conditions ◽  
Shallow Water Area ◽  
Wave Conditions ◽  
Direct Measures

An instrumentation system to record direct measures of both wind and wave conditions has been installed at the Wash. Data from these instruments are used in conjunction with long term wind records from another station to predict the frequency and duration of extreme conditions.

scholarly journals APPLICATION OF VIDEO IMAGES FOR MONITORING COASTAL ZONE IN HASAKI BEACH, JAPAN

2012 ◽  
Vol 1 (33) ◽  
pp. 43
Author(s):  
Muhammad Zikra ◽  
Noriaki Hashimoto ◽  
Masaru Yamashiro ◽  
Masaki Yokota ◽  
Kojiro Suzuki
Keyword(s):  
Shallow Water ◽  
Coastal Zone ◽  
Image Data ◽  
Field Measurements ◽  
Video Camera ◽  
Video Image ◽  
Wave Spectra ◽  
Digital Video Camera ◽  
Directional Wave ◽  
Pixel Brightness

The video image analysis methods are used for monitoring the phenomena at the coastal zone. A digital video camera which is mounted in the HORS research building is used to estimate directional wave spectra and bathymetry in shallow water areas. The Bayesian Directional Method is used to estimate directional wave spectra using the group of pixels brightness and non-linear bathymetry inversion is used to estimate shallow water bathymetry using time series of pixel brightness intensity at cross-shore and longshore array. The results are compared with a numerical model and field measurements. The results indicate that video image data could be used to estimate bathymetry and directional wave spectra in shallow water areas.

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