Effect Analysis of Polarization Aberration in the Non-Line-of-Sight Azimuth Transmission

2021 ◽  
Author(s):  
Zhiyong Yang ◽  
Junchen Song ◽  
Wei Cai ◽  
Danqiu Qiao ◽  
Gaoxiang Lu
Keyword(s):  
Normal Incidence ◽  
Transmission Error ◽  
Transmission System ◽  
Line Of Sight ◽  
Polarization Angle ◽  
Effect Analysis ◽  
Polarized Beam ◽  
Polarization Maintaining ◽  
Selection Of ◽  
Non Line Of Sight

Abstract Focusing on the problem that the polarization aberration caused by the non-normal incidence of the polarized beam affects the accuracy of the azimuth transmission during the fiber coupling process of the non-line-of-sight azimuth transmission system, this paper starts from the principle of non-line-of-sightazimuth transmission. The polarization aberration relation of the lens-fiber combined interface is established based on the Fresnel formulafor the attenuation difference between the horizontal and vertical electric vectors. Further, the azimuth solution model affected by polarization aberration is established. Numerical simulation results show that in non-normal incidence, no polarization aberration will occur when the polarization angle between the incident ray and incident surface is 0° or 90°. Otherwise, the polarization aberration changes toward the incident surface, and the azimuth transmission error will increase with the increase of the polarization aberration. Last, the optimization measures are proposed. This is of great significancefor further improvement of the azimuth transmission system based on polarization-maintaining fibers, the selection of the instrument,and the improvement of the system measurement accuracy.

Non-Line-of-Sight Azimuth Transmission Technology Based on Polarization-Maintaining Fiber

2020 ◽  
Vol 40 (15) ◽  
pp. 1512001
Author(s):  
蔡伟 Cai Wei ◽  
赵钟浩 Zhao Zhonghao ◽  
杨志勇 Yang Zhiyong ◽  
罗李娜 Luo Lina
Keyword(s):  
Line Of Sight ◽  
Polarization Maintaining Fiber ◽  
Polarization Maintaining ◽  
Non Line Of Sight

scholarly journals Analysis of the influence of a solenoid magnetic field in the azimuth transmission system

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhiyong Yang ◽  
Junchen Song ◽  
Wei Cai ◽  
Gaoxiang Lu ◽  
Zhiwei Zhang
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Superposition Principle ◽  
Transmission System ◽  
Middle Part ◽  
Equivalent Model ◽  
Line Of Sight ◽  
The Magnetic Field ◽  
Non Line Of Sight ◽  
Magneto Optic

AbstractA solenoid magnetic field plays an important role in a non-line-of-sight azimuth transmission system based on polarization-maintaining fiber, which is directly related to the transmission accuracy of azimuth information. This research mainly studies the factors that affect the solenoid magnetic field according to the modulation signal from the direct current to the alternating current, as well as the hollow solenoid. First, the magnetic field components of the static solenoid are derived from the Biot–Savart law by using the uniform cylindrical current equivalent model. Then, the magnetic field of the near axial region is studied from the axial and radial directions, and the feasibility of calculating the magnetic field of the multi-layer solenoid with the superposition principle is verified by measuring the magnetic field of each position on the axis of the solenoid with a Gauss meter. Finally, the alternating electromagnetic field model is established using Maxwell’s equations, and the magnetic and electric fields of the hollow solenoid are further solved. The results show that the magnetic field in the middle part of the magneto-optic glass is more stable, and the magnetic collecting ability of the solenoid is stronger. The magnetic field intensity at the center of the magneto-optic modulation solenoid of the system is the largest, and it decreases with the distance from the center. The alternating electromagnetic field is closely related to frequency. The results provide a reference for the study of the azimuth accuracy of a non-line-of-sight azimuth transmission system.

Integrating the Non-Line of Sight Launching System (NLOS-LS) in the United States Navy

2007 ◽  
Author(s):  
Jonathon Emis ◽  
Bryan Huang ◽  
Timothy Jones ◽  
Mei Li ◽  
Don Tumbocon
Keyword(s):  
United States ◽  
United States Navy ◽  
The United States ◽  
Line Of Sight ◽  
Non Line Of Sight

scholarly journals Low-cost SPAD sensing for non-line-of-sight tracking, material classification and depth imaging

2021 ◽  
Vol 40 (4) ◽  
pp. 1-12
Author(s):  
Clara Callenberg ◽  
Zheng Shi ◽  
Felix Heide ◽  
Matthias B. Hullin
Keyword(s):  
Low Cost ◽  
Line Of Sight ◽  
Depth Imaging ◽  
Material Classification ◽  
Non Line Of Sight

scholarly journals Target Localization via Integrated and Segregated Ranging Based on RSS and TOA Measurements

Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 230 ◽  
Author(s):  
Slavisa Tomic ◽  
Marko Beko
Keyword(s):  
State Of The Art ◽  
Hybrid Approach ◽  
Critical Distance ◽  
Heuristic Approach ◽  
Target Localization ◽  
Line Of Sight ◽  
Time Of Arrival ◽  
Individual Measurement ◽  
New Approach ◽  
Non Line Of Sight

This work addresses the problem of target localization in adverse non-line-of-sight (NLOS) environments by using received signal strength (RSS) and time of arrival (TOA) measurements. It is inspired by a recently published work in which authors discuss about a critical distance below and above which employing combined RSS-TOA measurements is inferior to employing RSS-only and TOA-only measurements, respectively. Here, we revise state-of-the-art estimators for the considered target localization problem and study their performance against their counterparts that employ each individual measurement exclusively. It is shown that the hybrid approach is not the best one by default. Thus, we propose a simple heuristic approach to choose the best measurement for each link, and we show that it can enhance the performance of an estimator. The new approach implicitly relies on the concept of the critical distance, but does not assume certain link parameters as given. Our simulations corroborate with findings available in the literature for line-of-sight (LOS) to a certain extent, but they indicate that more work is required for NLOS environments. Moreover, they show that the heuristic approach works well, matching or even improving the performance of the best fixed choice in all considered scenarios.

scholarly journals Non-Line-of-Sight Imaging with Picosecond Temporal Resolution

2021 ◽  
Vol 127 (5) ◽  
Author(s):  
Bin Wang ◽  
Ming-Yang Zheng ◽  
Jin-Jian Han ◽  
Xin Huang ◽  
Xiu-Ping Xie ◽  
...  
Keyword(s):  
Temporal Resolution ◽  
Line Of Sight ◽  
Non Line Of Sight

scholarly journals Thermal non-line-of-sight imaging from specular and diffuse reflections

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Masaki Kaga ◽  
Takahiro Kushida ◽  
Tsuyoshi Takatani ◽  
Kenichiro Tanaka ◽  
Takuya Funatomi ◽  
...  
Keyword(s):  
Angular Distribution ◽  
Heat Source ◽  
Real World ◽  
Diffuse Reflection ◽  
Far Infrared ◽  
Infrared Light ◽  
Line Of Sight ◽  
Thermal Camera ◽  
Reflection Component ◽  
Non Line Of Sight

Abstract This paper presents a non-line-of-sight technique to estimate the position and temperature of an occluded object from a camera via reflection on a wall. Because objects with heat emit far infrared light with respect to their temperature, positions and temperatures are estimated from reflections on a wall. A key idea is that light paths from a hidden object to the camera depend on the position of the hidden object. The position of the object is recovered from the angular distribution of specular and diffuse reflection component, and the temperature of the heat source is recovered from the estimated position and the intensity of reflection. The effectiveness of our method is evaluated by conducting real-world experiments, showing that the position and the temperature of the hidden object can be recovered from the reflection destination of the wall by using a conventional thermal camera.

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