A Study on Electromagnetic Compatibility of Navigation in the Sea Region near Land

在本论文中，第一章回顾了无线电波应用及其分配的历史研究进展，第二章讨论了罗兰-C波在海岸线附近的行为。当一艘船靠近海岸时，罗兰-C波的次波从陆地重新辐射，主波和次波相互重叠。然后，在750-800m的间隔内，主次波叠加产生的无线电波速度变得越来越快和越来越慢。这些结果也得到了数值计算的解释。第三章和第四章讨论了巨型桥梁对Decca波和Loran-C波的扰动问题。为了从理论上解释Seto-Ohashi桥的二次辐射机制，利用Decca波进行了多次实验。根据这些结果，可以认为几个高的桥塔是垂直电偶极子天线。根据对Decca波电场强度的测量，将每对高桥塔模拟为垂直电偶极子天线，其静态电容约为0.2muF，从而建立了由两个平行的垂直电偶极子天线组成的桥梁天线模型，每个天线的静态电容为0.2muF。此外，为了研究定位误差的大小，在Seto-Ohashi桥附近用接收机对罗兰-C波的相位进行了测量，参考了一台高稳定的Rb束振荡器。从测量结果可以看出，在桥两侧200米至1500米的较宽范围内，相位误差从正负0.2mus到正负0.4mus不等。这些相位误差对应于&lt；正负&60-&lt；正负120米的距离。最后，第五章对全文进行了总结。

In this thesis, the first chapter gives a review of the progress of historical research of radio wave application and its assignment.In the second chapter, the behavior of the Loran-C wave near a coast line is discussed. As a ship approaches the seashore, the secondary wave of the Loran-C wave is reradiated from land, and the primary wave and secondary wave overlap each other. Then, the velocity of radio wave resulting from superposition of the primary wave and the secondary wave gets faster and slower in an interval of 750-800m. These results are also interpreted by the numerical calculations. In the third and fourth chapter, the disturbance problems of Decca waves and the Loran-C waves caused by huge bridges are discussed. In order to elcidate theoretically the mechanism of the secondary radiation from Seto-Ohashi-Bridge, several experiments were carried out by using Decca waves. According to these results, a couple of high bridge-towers could be considered to be vertical electric dipole antennas. From the measurements of electric field strength of Decca waves, the static capacitance of each pair of high bridge-towers, which are modeled as a vertical electric dipole antennas, is about 0.2muF.Hence, it is possible to establish an antenna model of the bridge consisting of two parallel vertical electric dipole antennas with 0.2muF static capacitance in each. Furthermore, in order to investigate the magnitude of positioning errors, the phase measurements of Loran-C waves with the receiver, referenced to a highly stable Rubidium beam oscillator, were carried out near Seto-Ohashi bridge. From the results of measurement, it could be observed that in a wide region on both sides of the bridge far from 200m to 1,500m, the phase errors vary from <plus-minus> 0.2mus to <plus-minus> 0.4mus in time. These phase errors correspond to <plus-minus> 60 - <plus-minus> 120m in distance. Finally this thesis is concluded in the fifth