Study On Determining Search Area Model For SAR At Sea

The ocean is a very important basis for human survival and development. With the rapid development of China's economy, the economy activities taken place in sea is becoming more and more frequent, such as transport, fisheries, resource development and tourism. However, due to the complexity and variability of the marine environment, maritime accidents occurred frequently, which would not only pose a serious threat to the lives and property, but also cause immeasurable pollution to the marine environment. Providing good SAR services is not only the internal needs to ensure safety of navigation, and it is an important guarantee for full, healthy and sustainable development of China's marine economy. In order to improve the success rate of SAR, it is critical to rapidly and accurately determine the search area and the evolving over time of the people and vessels in distress. The determination of best search area can reduce blindness and deploy SAR forces more effectively in search and rescue operations, so it could provide technical support for carrying out SAR operations.On basis of analyzing the factors impact on the drift of floating objects, the total motion of the object is simplified as superposition of current and leeway. The main factors considered in this paper are wind, flow, types of floating object and the initial position error. FVCOM model is adopted for numerical forecasting of the surface flow field in the accident sea, and the calculated results are compared with experimental results and it is indicated that the results agree well. Empirical formula method for the relation between wind and the motion of the drifting object is employed. It is assumed that the position of a drifting object behaves as a Markov process. A Monte Carlo method is introduced to quantify leeway and the initial position errors, and after a large number of repeated calculations, the trajectories and the final search area would be defined. Finally, a programming model is established to determine the search area, and the GUI of Matlab language is used to compile an illustrative software interface.The determining maritime search area model is tested by the actual SAR case happened in Liaodong Bay. The model result is close to the final position of the accident ship, and the final position is included in the search. So the results show that the established model for determining maritime search area can basically meet the needs of maritime SAR.