Using magnetic perturbation for estimating velocity of a moving magnetic target

• Main Authors: Shun-HwanLin, 林聖桓
• Other Authors: Ching-Jer Huang
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/17450323405458141810

碩士 === 國立成功大學 === 水利及海洋工程學系碩博士班 === 100 === The magnetic field signature has been implemented as a weapon and detection system for more than 80 years. The structure of a ship was made up of wood at the beginning. But, in order to survive for those warships during war, the wooden hull was replaced by iron or steel cladding. During the casting process of a ship, the permanent magnetic field will result from the characteristics of the ship, which can be applied as a basis to identify a ship. Due to the reason that the magnetic source of a ship might be cluttered, a simple magnet model is considered in this research. There are three purposes of this study. One of the purposes is to understand the effects for various moving speeds of the magnet on the frequency spectrum. The second purposes is to figure out the effects of different directions of the magnet moving over the magnetometer, and lastly, to understand at the frequency domain of a magnet by changing the depth and athwartship distance. Artificial neural network was applied to estimate the speed of a ship found in the same depth, athwartship distance, regardless of its moving direction. According to the research results, regardless of the moving direction of the magnet, the accuracy of estimated the speed is more than 80% under the consideration of the same depth and athwart ship distance.