Analysis of polarization characteristics of backscattered light and reflected light of underwater active light source

2021 ◽  
Vol 60 (12) ◽  
Author(s):  
Qian Cheng ◽  
Yingmin Wang ◽  
Dongxin Li
Keyword(s):  
Light Source ◽  
Reflected Light ◽  
Polarization Characteristics

Simplified field measurement methods for the CIE mesopic photometry system

2016 ◽  
Vol 49 (6) ◽  
pp. 774-787 ◽  
Author(s):  
T Uchida ◽  
Y Ohno
Keyword(s):  
Light Source ◽  
Spectral Reflectance ◽  
Spectral Power ◽  
Road Surface ◽  
Worst Case ◽  
Distribution Method ◽  
The Road ◽  
Reflected Light ◽  
Test Points ◽  
Adaptation Field

For implementation of the mesopic photometry system in CIE 191:2010 to outdoor lighting, two simplified methods to measure the mesopic luminance are proposed. One of the methods, named the Adaptation Spectral Power Distribution) method, assumes that the spectral power distributions (SPDs) of reflected light at test points on the road surface are the same as that of the adaptation field. Another method, named the Source SPD method, assumes that the reflected light SPDs are equal to the SPD of the light source. Error simulations with a real road surface spectral reflectance dataset show that the error distributes over an 8% range due to the variation of the road surface spectral reflectance in the worst case. Although the bias due to the road surface spectral reflectances causes a large error with the Source SPD method, a proposed correction can reduce the error sufficiently. Error simulations also show that the Source SPD method is not so sensitive for lighting scenes that include multiple light source types. It has been shown that the SPD methods can measure the mesopic quantities without scotopic/photopic luminance meters having both V( λ) and V′( λ) detectors when both the adaptation field and test points consist of road surfaces.

Method for Testing and Analyzing the Printing Performance of Fluorescent Inks

2014 ◽  
Vol 556-562 ◽  
pp. 2779-2782
Author(s):  
Pan Pan Yang ◽  
Yan Fang Xu ◽  
Na Gao ◽  
Ya Yuan Zhang
Keyword(s):  
Light Source ◽  
Ultraviolet Light ◽  
Vertical Direction ◽  
Luminescent Properties ◽  
Radiation Energy ◽  
Energy Data ◽  
Unique Color ◽  
Reflected Light ◽  
Dot Gain ◽  
To Receive

In recent years, fluorescent ink, with a unique color performance and the advantages of green non-toxic, fast drying, thin ink, etc., is widely used in packaging printing, security printing, and other fields. What’s more, the luminescent properties and the interaction with paper of fluorescent ink are pained more and more attention. In this experiment, an ultraviolet light source is used to motivate the samples to emit, the fiber spectrophotometer is used to receive the reflected light of the samples in the vertical direction of the samples. The tone rendering curve and dot gain curve are obtained according to the radiation energy data of the sample, the printing indicators of fluorescent ink are obtained by analyzing the reproducing image tone scale and dot expansion characteristics of ink on the paper.

A 3D Profile Parallel Detecting System Based on Differential Confocal Microscopy

2005 ◽  
Vol 295-296 ◽  
pp. 501-506
Author(s):  
Y.H. Wang ◽  
X.F. Yu ◽  
Ye Tai Fei
Keyword(s):  
Confocal Microscopy ◽  
Light Source ◽  
Sampling Interval ◽  
Differential Method ◽  
Reconstruction Method ◽  
Reflected Light ◽  
Measuring Efficiency ◽  
Working Principle ◽  
3D Profile ◽  
Profile Reconstruction

Based on the differential confocal microscopy principle, a non-scanning 3D profile detecting system is proposed. A 2D light source array produced by micro-optic components is used to form a parallel micro-confocal system. The whole field detecting of the measuring plane is realized. The reflected light beam is divided into two paths. Two CCD cameras work together to detect the facula array in a differential arrangement. A differential algorithm of facula intensity is used. The noise and the shift of light source can be avoided effectively. Using the linearity characteristic of the differential confocal system, the high axial resolution is achieved at a larger sampling interval. The measuring efficiency and accuracy can be increased. The construction and working principle of the 3D parallel detecting system and the 3D profile reconstruction method are investigated. Experiment results agree with the ones of theory analysis. It indicates that the differential method is applicable for non-scanning 3D profile detection.

scholarly journals A model of degree of scattering polarization for oil spilling

2020 ◽  
Vol 50 (3) ◽  
Author(s):  
Xiao Wang ◽  
Jiang Xu ◽  
Weixian Qian ◽  
Jingyi Ouyang
Keyword(s):  
Optical Sensors ◽  
Stokes Parameter ◽  
Polarization Measurement ◽  
Fresnel Reflection ◽  
Oil Film ◽  
Scattering Rate ◽  
Reflected Light ◽  
Polarization Characteristics ◽  
Fresnel Formula ◽  
Spilled Oil

Oil slicks often show uncertain surface roughness and Fresnel reflection parameters. Consequently, differentiating oil spilled on the seawater in these areas using optical sensors is a challenge. Therefore, the optical mechanism of the oil film has been studied by the Maxwell equation. It is found that the polarization characteristics of the oil slicks can help us to overcome this problem. According to the Fresnel formula, the scattering coefficient and scattering rate of the homogeneous oil film have been deduced, and the phase difference of the scattering electromagnetic wave has also been calculated to verify the accuracy of the model. The parameter, a degree of scattering polarization, has been derived to identify the oil slicks on the sea wave. It depends on accurately knowing the Stokes parameter for the reflected light, and varies with the refractive index of the surface layer and viewing angles. The actual spilled oil has been measured by this model, and the oil film can be accurately identified at various angles. These preliminary results suggest that the potential of multi-angle polarization measurement of ocean surface needs further researches.

Reflected-light-source-based three-dimensional display with high brightness

2016 ◽  
Vol 55 (13) ◽  
pp. 3452 ◽  
Author(s):  
Guo-Jiao Lv ◽  
Fei Wu ◽  
Wu-Xiang Zhao ◽  
Jun Fan ◽  
Bai-Chuan Zhao ◽  
...  
Keyword(s):  
Light Source ◽  
Three Dimensional ◽  
High Brightness ◽  
Reflected Light ◽  
Three Dimensional Display

Design of a Fiber Optic Pressure Transducer

1977 ◽  
Vol 99 (1) ◽  
pp. 274-279 ◽  
Author(s):  
R. H. Pahler ◽  
A. S. Roberts
Keyword(s):  
Light Intensity ◽  
Light Source ◽  
Pressure Transducer ◽  
Fiber Optic ◽  
Light Guide ◽  
Circular Array ◽  
Analytic Procedure ◽  
Reflected Light ◽  
Cylindrical Metal ◽  
Selection Of

Performance characteristics of a fiber optic pressure transducer are presented and discussed. The transducer consists of a cylindrical metal housing with a specular reflecting aluminum diaphragm at the distal end and a circular array of fiber optic light guide bundles at the proximal end. The center bundle is connected to a light source with the surrounding bundles carrying reflected light to a photodetector. A change in pressure on the diaphragm produces a differential change in light intensity. An analytic procedure guides the selection of an optimal configuration in order to obtain maximum transducer response.

scholarly journals Why do mayflies lay their eggs en masse on dry asphalt roads? Water-imitating polarized light reflected from asphalt attracts Ephemeroptera.

1998 ◽  
Vol 201 (15) ◽  
pp. 2273-2286 ◽  
Author(s):  
G Kriska ◽  
G Horváth ◽  
S Andrikovics
Keyword(s):  
Polarized Light ◽  
Reproductive Activity ◽  
Egg Laying ◽  
Degree Of Polarization ◽  
The Road ◽  
Large Numbers ◽  
Reflected Light ◽  
Polarization Characteristics ◽  
Higher Temperature ◽  
Great Danger

We report on dry asphalt roads acting as 'mayfly traps'; that is, they lure swarming, mating and egg-laying mayflies in large numbers. To explain this surprising behaviour, we performed multiple-choice experiments with Ephemeroptera in the field, and measured and compared the reflection-polarization characteristics of an asphalt road and a mountain creek from which mayflies emerge. We show here that Ephemeroptera can be deceived by and attracted to dry asphalt roads because of the strongly horizontally polarized light reflected from the surface. Asphalt surfaces can mimic a highly polarized water surface to Ephemeroptera. The darker and smoother the asphalt surface, the higher is the degree of polarization of reflected light and the more attractive is the road to mayflies. We show that mayflies detect water by means of polarotaxis; that is, on the basis of the partially and horizontally polarized reflected light. Asphalt roads are excellent markers for swarming Ephemeroptera because of their conspicuous elongated form; the sky above them is usually open, which is the prerequisite of mayfly mating, and the higher temperature of the asphalt prolongs the reproductive activity of mayflies. These additional factors enhance the attractiveness of asphalt roads to swarming mayflies. Thus, asphalt roads near ephemeropteran emergence sites (lakes, rivers and creeks) are a great danger for mayflies, because eggs laid on the asphalt inevitably perish. Asphalt roads can deceive and attract mayflies en masse like the ancient tar pits and asphalt seeps or the recent crude or waste oil lakes deceive, lure and trap polarization-sensitive water-seeking insects in large numbers.

Development of Quantitative Analytical Instrument for Colloidal Gold Strips

2012 ◽  
Vol 591-593 ◽  
pp. 1872-1876 ◽  
Author(s):  
Yang Wang ◽  
Kai Jiang ◽  
Ping Wang
Keyword(s):  
Light Source ◽  
Colloidal Gold ◽  
Detection System ◽  
Test Strip ◽  
Step Motor ◽  
Test Results ◽  
Analytical Instrument ◽  
Photoelectric Detection ◽  
Reflected Light ◽  
Source Signals

A novel analytical instrument for quantitative testing colloidal gold strips is developed based on the principle of photoelectric detection. The test-strip analytical instrument uses green LEDs as the emitting light source and a photodiode as the receiving device for obtaining reflected light, and utilizes a step motor to drive detection system for scanning the examining areas. Modulation technique for light source signals and demodulation technique for receipt signals are used to eliminate the interference of the background noise. The test results indicate the system has high detection veracity rates with detecting errors less than 1%, and good detection stability with coefficient variables less than 2%.

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