Surface signatures of oceanic internal waves (IWs) are often observed in synthetic aperture radar (SAR) images since IWs change surface roughness through the interaction of small-scale ocean waves with varying currents induced by IWs. If we know the relationship between the vertical and horizontal parameters governing IWs, the mixed layer depth (MLD) can be estimated from SAR data since IWs propagate along a pycnocline where the water density changes rapidly. This study presents a method for estimating MLD from SAR data using IW images observed by RADARSAT-1 over the east waters of the Korean Peninsula. To interpret IWs using SAR data, the backscatter radar cross section is computed by applying the small perturbation model to the sea surface perturbed by varying surface currents. Wave height spectrum is computed by varying the upper layer depth of mixed layer from 5 m to 100 m with 1 m depth interval. The surface current field is assumed to move with the IWs, and is described by the KdV equation. The computed RCS is then compared with the RADARSAT-1 data, resulting in satisfactory agreement of the estimated depth of IWs with other data.
When we talk about for the ship detection, identification and its classification, we need to go for the wide area of monitoring and it may be possible only through satellite based monitoring approach which monitors and covers coastal as well as the oceanic zone. Synthetic aperture radar (SAR) has been widely used to detect targets of interest with the advantage of the operating capability in all weather and luminance free condition (Margarit and Tabasco, 2011). In EU waters, EMSA(European Maritime Safety Agency) is operating the SafeSeaNet and CleanSeaNet systems which provide the current positions of all ships and oil spill monitoring information in and around EU waters in a single picture to Member States using AIS, LRIT and SAR images. In many countries, a similar system has been developed and the key of the matter is to integrate all available data. This abstract describes the preliminary design concept for an integration system of RADAR, AIS and SAR data for vessel traffic monitoring. SAR sensors are used to acquire image data over large coverage area either through the space borne or airborne platforms in UTC. AIS reports should be also obtained on the same date as of the SAR acquisition for the purpose to perform integration test. Land-based RADAR can provide ships positions detected and tracked in near real time. In general, SAR are used to acquire image data over large coverage area, AIS reports are obtained from ship based transmitter, and RADAR can monitor continuously ships for a limited area. In this study, we developed individual ship monitoring algorithms using RADAR(FMCW and Pulse X-band), AIS and SAR(RADARSAT-2 Full-pol Mode). We conducted field experiments two times for displaying the RADAR, AIS and SAR integration over the Pyeongtaek Port, South Korea.
In the case of oil spill accident at sea, cause the bad effect onto the around sea area such as ocean pollution, property
loss etc. Quick making response strategies must be need to prevent additional damage and that is possible by developing
system with offered integrated information, such as accident position, oil spill area, oil spill trajectories and combating
resources. This paper presents the GIS system for visualization of oil spill monitoring and predicting movement. The
purpose of this system is to easily understand of integrated oil spill information by plot on a program base on electronic
navigation chart. Oil spill analysis tool is offer input data such as outline coordinates of detected oil spill, the information
about the source satellite image and any possible sources in satellite image. This system is designed to plot oil spill on
specific time and predicting oil spill trajectories with currents and winds. Each data is extracted by computer modeling
using MATLAB. Oil spill movement must be superimposed both 100% of the current strength and 3% of the wind speed.
The system will be developed and planned to monitor and forecast oil spilled area. At the same time, it will be planned to
predict a projected path of oil spill by collecting environmental information.
This abstract describes the preliminary design concept for an integration system of SAR and AIS data. SAR sensors are used to acquire image data over large coverage area either through the space borne or airborne platforms in UTC. AIS reports should also obtained on the same date as of the SAR acquisition for the purpose to perform integration test. Once both data reports are obtained, one need to match the timings of AIS data acquisition over the SAR image acquisition time with consideration of local time and boundary to extract the closest time signal from AIS report in order to know the AIS based ship positions, but still one cannot be able to distinguish which ships have the AIS transponder after projection of AIS based position onto the SAR image acquisition boundary. As far as integration is concerned, the ship dead-reckoning concept is most important forecasted position which provides the AIS based ship position at the time of SAR image acquisition and also provides the hints for azimuth shift which occurred in SAR image for the case of moving ships which moves in the direction perpendicular to the direction of flight path. Unknown ship's DR estimation is to be carried out based on the initial positions, speed and course over ground, which has already been shorted out from AIS reports, during the step of time matching. This DR based ship's position will be the candidate element for searching the SAR based ship targets for the purpose of identification and matching within the certain boundary around DR. The searching method is performed by means of estimation of minimum distance from ship's DR to SAR based ship position, and once it determines, so the candidate element will look for matching like ship size match of DR based ship's dimension wrt SAR based ship's edge, there may be some error during the matching with SAR based ship edges with actual ship's hull design as per the longitudinal and transverse axis size information obtained from the AIS reports due to blurring effect in SAR based ship signatures, once the conditions are satisfied, candidate element will move and shift over the SAR based ship signature target with the minimum displacement and it is known to be the azimuth shift compensation and this overall methodology are known to be integration of AIS report data over the SAR image acquisition boundary with assessment of time matching. The expected result may provide the good accuracy of the SAR and AIS contact position along with dimension and classification of ships over SAR image. There may be possibilities of matching speed and course from candidate element with SAR based ship signature, but still the challenges are presents in front of us that to estimation of speed and course by means of SAR data, if it may be possible so the expected final result may be more accurate as due to extra matching effects and the results may be used for the near real time performance for ship identification with help of integrated system design based on SAR and AIS data reports.