Phase pattern distortions of the medum-wave band antenna placed on the carrier

Terrestrial radio navigation systems are relevant tools for the definition of maritime vessels. Thus, according to the requirements of maritime traffic, any vessel should have several navigation systems for backup in case of unforeseen situations and loss of communication with the main navigation systems, as well as for coordinate specification. An important component of any navigation system is the receiving antenna. The article is devoted to the study of the influence of the receiving medium-wave antenna surrounding on its phase directivity characteristic, since the accuracy of radio navigation depends on the uniformity of the phase characteristic (both in frequency and azimuth). The paper shows that the presence of ship masts and the shape of the carrier itself can have a significant effect on navigation accuracy. To reduce this effect, it is possible to raise the receiving antenna above the carrier or use software utilizing calibration tables.