Mathematical models and algorithms for modeling the location signals reflected from the underlying surfaces of the earth, sea and coastal waters

摘要

In developing the on-board equipment of aircraft, used radar maps for navigation, there is a need for mathematicalmodel's signals, reflected from the Earth's surface, sea surface and coastal edge. Traditionally, using a theoreticalconstruct, stochastic signals were used as such models and its fluctuations were described by Rayleigh and Rayleigh-Rice. These models are used both for simulation signals, reflected from the Earth's surface, and for signals, reflectedfrom the surface of the sea. At low resolution capability of on-board radars, the similar models describe quite well thestatistical characteristics of fluctuating signals. Modern on-board locator has high resolution capability and the Rayleighand Rice’s models can no longer be used in the synthesis and simulation of modern on-board navigation systems.In this paper, we propose an approach to the construction of models of radar signals using both theoretical constructs andexperimental data that allows you to take into account the features of reflection of radar signals from small plots of theUnderlying Surface of earth and sea. Along with it the correlations between the individual sections and anisotropicreflections are taken into account when observing sites with different angles. The reflections from the sea surfaceapproximated by a log-normal law, reflections from the earth's surface at the sight of the manifold types of surface by theBeckmann and Weibull laws, special cases of which are the laws of Rice, Rayleigh and Hoyt. As the reflection model ofthe edge uses the distribution law of the vector sum of the signals, reflected from the elementary areas of earth and sea,getting in the resolution cell. In this case, the law of distribution of the total vector is subject to a law similar to Huber'slaw, in which the above-mentioned laws of distribution of reflections from the earth and the sea are used as the basicdistributions. Previously used reflection models turned out as special cases of the proposed models.These models and the modeling algorithms developed for them can be used in the development and research of highprecisionmethods of radar monitoring for the purposes of environmental reconnaissance, forecasting and promptprevention of natural and man-made emergency situations. In addition, for testing the operating modes of the equipmentof unmanned aerial vehicles, including for multi-position radar systems.Algorithms for modeling location signals based on mathematical models using experimental data of reflections fromvarious types of underlying land and sea surfaces, as well as coastal edges (coastal waters), allow us to bring the resultsof computer experiments to the results of actual tests of radio-electronic equipment. This reduces the time and reducesthe cost of design by reducing the semi-natural and full-scale tests.