Method for analyzing plasma-sheath-caused multipath interference on aircraft surfaces

A plasma sheath and multipath interference technology, applied in the field of satellite navigation, can solve the problem that the plasma sheath model cannot analyze the multipath effect, etc.

Active Publication Date: 2014-02-19
南通安广美术图案设计有限公司
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  • Abstract
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Problems solved by technology

[0005] The purpose of the present invention is to provide a method for analyzing the multipath interference generated by the plasma sheath on the surface of the aircraft, which solves the problem that the existing plasma sheath model cannot analyze the multipath effect

Method used

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  • Method for analyzing plasma-sheath-caused multipath interference on aircraft surfaces
  • Method for analyzing plasma-sheath-caused multipath interference on aircraft surfaces
  • Method for analyzing plasma-sheath-caused multipath interference on aircraft surfaces

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Embodiment 1

[0061] The numerical simulation method uses FDTD, and the calculation model is as figure 1 The plasma shown ( figure 1 Middle ③) The coordinates of the start point are (1, 30), and the coordinates of the end point are (1000, 330), that is, the angle α=16.7° with the surface of the aircraft. The plasma thickness is 6 cm (12 × dy). The FDTD calculation area is a total of 400×1000 grids, PML ( figure 1 Middle ②) The thickness is 10 grids, the grid is divided into dx=dy=0.5cm, the uniform plasma thickness is 6cm (12×dy) located in the 30-41 grid in the y direction, the plasma collision frequency υ=1e10Hz, the electron density ne=10 17 m -3 . aircraft surface ( figure 1 Middle ⑤) is located at 19 grids in the y direction. Each antenna ( figure 1 Middle ④) is 9cm apart, and the coordinates are (50, 20), (68, 20), (86, 20), (104, 20), (122, 20), (140, 20), (158, 20 ), (176, 20). The added source is the GPS signal center frequency 1.57542GHz plane wave ( figure 1 Middle ①)....

Embodiment 2

[0063] The numerical simulation method uses FDTD, and the calculation model is as image 3 Actual plasma introduced as shown ( image 3 Middle ③)) thickness is 10 grids, grid division dx=dy=0.5cm, plasma collision frequency υ=1e9Hz, electron density ne=10 18 m -3 . aircraft surface ( image 3 Middle ⑤) is located in the y direction with a length of 2m. Each antenna ( image 3 Middle ④) is 9cm apart, and the coordinates are (50, 20), (68, 20), (86, 20), (104, 20), (122, 20), (140, 20), (158, 20 ), (176, 20). The added source is a 1.57542GHz plane wave ( image 3 Middle ①). When estimating the direction of arrival, the MUSIC algorithm is used, and the signal is subjected to forward smoothing decoherence processing, wherein the total number of array elements is M=8, and the number of sub-array elements is m=4. from Figure 4 It can be seen that 21.7° and 59.2° are the directions of multipath interference.

[0064] The inventive point of the present invention is that on...

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Abstract

The invention discloses a method for analyzing plasma-sheath-caused multipath interference on aircraft surfaces. The method includes firstly, using a flow field distribution file to input frequency, direction and power of navigation signals; calculating according to the MUSIC algorithm and the decorrelation algorithm to acquire interference signals. Direction of arrival is estimated based on the MUSIC algorithm of the decorrelation processing technology, so that the method is applicable to judgment on influence magnitude of the multipath interference in satellite navigation systems. Since multipath magnitude and incoming direction can be estimated, the method can support for eliminating multipath influences.

Description

technical field [0001] The invention belongs to the technical field of satellite navigation, and in particular relates to a method for analyzing multipath interference generated by a plasma sheath on the surface of an aircraft. Background technique [0002] The process from re-entering the atmosphere to landing is called the re-entry process. During the reentry process, the hypersonic vehicle interacts with the atmosphere, forming a bow-shaped detachment shock wave in front of the vehicle. The heat-resistant ablation material is ablated under the action of high temperature and high heat flow, and the ablation products are released into the flow field around the aircraft, forming a complex reentry flow field with various components. The re-entry flow field is a mass of ionized gas. When the degree of ionization of the gas reaches a certain level, the ionized gas exhibits the collective behavior of plasma and becomes a plasma. At this time, the re-entry flow field is also cal...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G06F17/50
Inventor 刘江凡杜永兴席晓莉
Owner 南通安广美术图案设计有限公司
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