Integration method for predicating ground wave propagation attenuation factor at high precision

A technology of attenuation factor and ground wave propagation, applied in the direction of electromagnetic field characteristics, etc., can solve the problems of large error in predicted attenuation factor and large computing resources, etc.

Inactive Publication Date: 2011-01-05
XIAN UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0006] The purpose of the present invention is to provide a high-precision integral method for predicting the attenuation factor of ground wave propagation, which solves the problem of using the integra

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  • Integration method for predicating ground wave propagation attenuation factor at high precision
  • Integration method for predicating ground wave propagation attenuation factor at high precision
  • Integration method for predicating ground wave propagation attenuation factor at high precision

Examples

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Embodiment 1

[0075] Prediction of 100kHz Ground Wave Propagation Attenuation Factor for Short Distance Propagation

[0076] figure 1 It is the terrain distribution of the 100kHz signal propagation path from point A of the transmitting station to point B of the receiver. The total propagation distance is 100km, where C is the numerical calculation area of ​​the electromagnetic field (40km away from the transmitting point, and the range is 20km), which includes a region with severe terrain changes. Steep Gaussian mountains. The relative permittivity of the ground ε r is 13, the conductivity σ is 0.003S / m, and the expression of the terrain function z(ρ) is as follows:

[0077] z ( ρ ) = 1500 e - 9 ( ρ - 50 2 ...

Embodiment 2

[0085] Prediction of 100kHz Ground Wave Propagation Attenuation Factor for Long Distance Propagation

[0086] Figure 4 is the topographical distribution of the 100kHz signal propagation path from point A of the transmitting station to point B of the receiver, wherein C is the numerical calculation area of ​​the electromagnetic field (range of 300km-320km from the transmitting point), and the region with severe topographical changes is the same as in embodiment 1, and the ground is relatively medium Electrical constant ε r is 13, the conductivity σ is 0.003S / m, and the expression of the terrain function z(ρ) is as follows:

[0087] z ( ρ ) = 1500 e - 9 ( ρ - 50 2 ) ...

Embodiment 3

[0094] Prediction of 100kHz Ground Wave Propagation Attenuation Factor in Land-Sea Boundary Area Propagation

[0095] Figure 7 It is the topography and object distribution of the propagation path of the 100kHz signal from point A of the transmitting station to point B of the receiver, where C is the numerical calculation area of ​​the electromagnetic field (300km-320km away from the transmitting point), and the abrupt change area of ​​the objects included is different land objects and land In the sea boundary area (the boundary point is at 310km), the relative permittivity of the land ε r is 13, the conductivity is 0.003S / m, and the relative permittivity of seawater ε r is 80, and the conductivity σ is 5S / m.

[0096] The concrete steps of adopting the method of the present invention to propagate the attenuation factor amplitude and phase calculation are:

[0097] 1) Calculated using the integral equation method (formulas (1) and (3)) Figure 7 The incident feed plane show...

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Abstract

The invention discloses an integration method for predicating a ground wave propagation attenuation factor at high precision, comprising the following steps of: calculating an attenuation factor of a radio wave propagation path by using an integration equation method; selecting a number calculation area in terrain change violent and ground feature mutant local areas; selecting and using electric field distribution on the radio wave propagation incident surface of the area, which is calculated by using the integration method, as an exciting source; recalculating the propagation attenuation factor of the area by using an electromagnetic filed number calculating method; and replacing the attenuation factor calculated by number by the calculation result in the area through the integration method to obtain the attenuation factor of the whole propagation area. The invention can be used for reducing the error for predicating the terrain and ground feature mutant attenuation factor by using the integration equation method under the condition of adding the calculation resource at low amount.

Description

technical field [0001] The invention belongs to the field of theoretical calculation of radio wave propagation, in particular to an integral method for predicting ground wave propagation attenuation factors with high precision. Background technique [0002] The main calculation models and methods used in the existing ground wave propagation attenuation calculation are: uniform smooth spherical surface model (such as: Fock's ground wave diffraction calculation method), segmented uniform smooth spherical surface model (such as: Millington's empirical formula method, Wait integral method, wave mode conversion method), uneven and smooth spherical model (such as: integral equation method, parabola method). [0003] Early studies mainly used uniform and piecewise uniform smooth spherical models, but the prediction errors were relatively large. In recent years, the use of the integral equation method to solve the problem of complex path ground wave propagation has better predictio...

Claims

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Application Information

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IPC IPC(8): G01R29/08
Inventor 席晓莉周丽丽张金生
Owner XIAN UNIV OF TECH
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