There is a huge demand to develop a method for marine search and rescue（SAR） operators automatically predicting the most probable searching area of the drifting object. This paper presents a novel drifting prediction model to improve the accuracy of the drifting trajectory computation of the sea-surface objects. First, a new drifting kinetic model based on the geometry characteristics of the objects is proposed that involves the effects of the object shape and stochastic motion features in addition to the traditional factors of wind and currents. Then, a computer simulation-based method is employed to analyze the stochastic motion features of the drifting objects, which is applied to estimate the uncertainty parameters of the stochastic factors of the drifting objects. Finally, the accuracy of the model is evaluated by comparison with the flume experimental results. It is shown that the proposed method can be used for various shape objects in the drifting trajectory prediction and the maritime search and rescue decision-making system.
In order to overcome the shortcoming of poor accuracy and non-serious intuitivism of traditional wavelength calculation method in serious noise, a revised Radon transform algorithm is proposed by using a straight-line instead of using the wave＇s texture approximately applied to wavelength estimation. Firstly, Radon transform of the radar image is analyzed. Then, to obtain its fitting straight line combined with wave texture, the distance is calculated between straight lines to get the wavelength. Finally, the algorithm is programmed with Matlab on PC. The experimental results show that the proposed algorithm can improve the estimation accuracy of the wavelength with good visibility.
LU YingZHUANG XinqingSUN ZhenWANG ShengzhengLIU Wei
Locating the marine target in a quick and precise way is the crucial point of implementing SAR （search and rescue） at sea, which involves aspects of developing SAR strategy and detects the marine targets. As the effect of marine target detection restricts the SAR result directly, the study has focused on reviewing the previous research about marine target detection, especially dim marine target detection. What＇s more, small target detection under complex sea status is one of the severe challenges which is research＇s hotspot and needs more endeavor. Current research results and future research directions are discussed in the paper. The findings can provide systematic view of implementing maritime search and rescue for field researchers and governors.
