REDUCTION OF THE RANGE OF VISIBILITY OF MARINE OBJECTS OF THE SHIP'S RADAR DEPENDING ON THE INTENSITY OF PRECIPITATION

Abstract

Radar methods for researching the effect of precipitation on the radar observation of marine objects are based on the reflection and scattering of electromagnetic waves by the surface of the navigation object and precipitation particles. The incident electromagnetic wave excites secondary radiation on the surface of the marine object and particles of precipitation, which propagates in the direction of the ship's radar.

To assess the reflective properties of a marine object and precipitation, the effective backscattering area is introduced. Precipitation also weakens the radiation from the ship's radar system incident on them and leads to a decrease in the power of electromagnetic energy entering the input of the radar receiver, reflected from the marine object. This reduces the range of radar visibility of a marine object in the zone of precipitation.

Therefore, there is a need to establish the effect of precipitation on the radar observation of marine objects on the way of the vessel. The basis for obtaining a radar method for predicting the visibility range of a marine object at the minimum distance of its masking in precipitation are the equations of radar of a marine object and the precipitation zone on the ship's path.

Reducing the interfering effect of precipitation on the operation of a ship's radar is one of the urgent tasks of increasing the efficiency of using radar facilities. As the electromagnetic wave passes through the rain layer, the power flux density decreases. When radio waves fall on a rainfall zone in which a marine object is located, electromagnetic energy is scattered on a set of randomly located rainfall particles, each of which has a different shape, and phase state. Their arbitrary arrangement causes their mutual influence, and the incident wave propagates in the direction of their common axes of symmetry. At certain ratios of particle diameters, the distance between them, and the wavelength propagating through the rain zone, an additional total field arises due to multiple reflections, which affect the radar characteristics of the rainfall on the ship's path.