Crown’s anisotropy of a tree and scattering the signals of navigation satellites frequency band L1

Vladimir Podoprigora,Daniil Makarov,Dmitry Kharlamov,Anotoly Sorokin,V.B Kashkin,E Loupian,V Kharuk,M.V Noskov,Y.A Maglinets,G.M Tsibulśkii,L.G Sverdlik

doi:10.1051/e3sconf/202014902005

Abstract

The model of interaction of signals from navigation satellites with the tree crown is considered. The contribution of the anisotropy of the dielectric constant to the cross section of radio wave scattering due to the orientational ordering of the branches is shown. The calculation of the scattering cross sections for small and large elements is presented. The tensor of orientational ordering of tree branches with division into tiers differing in the size and orientation of elements is introduced. Test measurements of navigation satellite signals passed through the crowns of spruce trees were carried out.

Highlights

The study of the propagation of pulsed signals of navigation satellites (NS) in the forest is aimed at expanding the understanding of the nature of the interaction of polarized coherent electromagnetic waves (EMW) radiation in the frequency range 1-2 GHz with different-scale elements of trees and the stand as a whole
The complexity of using different models of the interaction of electromagnetic waves with the canopy is due to the dependence of the results on a large number of input parameters, including a noticeable dependence of the dielectric constant of wood on moisture and a variety of sizes and shapes of elements of the forest environment
The orientational ordering tensor of tree branches is introduced with the division into tiers differing in the size and orientation of the elements

Summary

Introduction

The study of the propagation of pulsed signals of navigation satellites (NS) in the forest is aimed at expanding the understanding of the nature of the interaction of polarized coherent electromagnetic waves (EMW) radiation in the frequency range 1-2 GHz with different-scale elements of trees and the stand as a whole. The ratios of the wavelength of NS signals with the sizes of the diverse structural elements of the forest range from much smaller units for leaves and needles, comparable to unity for the diameters of trunks and branches, and many large units for unevenly distributed groups of trees. This leads to many interaction mechanisms and approximations partially presented in reviews [1,2,3]. The development of a refractive model of the stand involves taking into account the distribution of bulk density of biomass and the orientational ordering of trunks and branches of crowns

Spatial orderliness the elements of trees stand

Attenuation of NS signals in the tree stand

Conclusion