摘要
根据一束光的偏振特性可以由斯托克斯矢量来表征的原理,设计搭建了一种天空偏振光测量系统。该系统由计算机、赤道仪、光纤光谱仪和配备了可旋转偏振片的改进式天文望远镜组成,在400～900nm的光谱分辨率为1.4nm。赤道仪经过标定后可以实现0～180°方位角以及0～90°高度角的调整,角度分辨率为2.5°。系统的光学全视场为4.5°,使用该系统可以测量全天空的光强辐射度、偏振度以及偏振方位角。由标定结果可知,系统光强测量的重复率在450～500 nm为99 %,在500～900 nm为(95±3)%;在400 ～750nm偏振度测量误差<2 %,在475nm处达到1.2 %。偏振方位角的测量误差<2°。
According to the principle that light polarization can be expressed with a Stokes vector, a new system to measure the polarized skylight distribution is developed. The system is composed of a computer, a modified equatorial mount, an optical fiber spectrometer and an improved astronomical telescope mounted with a rotatable linear polarizer. The spectral resolution of this system is 1.4 nm for the measurement when wavelength ranges from 400 nm to 900 nm. Using modified equatorial mount, the system can scan the points of celestial hemisphere at azimuth ranges from 0°to 180° and elevation 0° to 90° at an angular resolution of 2.5°. For a full-angle viewing field of 4.5°, this system can measure the radiance intensity, the Degree of Linear Polarization （DOLP）, and the Angle of Linear Polarization （AOLP） of the celestial. The calibration results show that the repeatability of intensity measurements is 99% in spectral ranges from 450 nm to 500 nm, and （95±3）% from 500 nm to 900 nm. The uncertainty of DOLP is less than 2% in spectral ranges from 400 nm to 750 nm, especially 1.2% at 475 nm. The angle error of AOLP is smaller than 2°.
出处
《光学精密工程》
EI
CAS
CSCD
北大核心
2009年第6期1431-1435,共5页
Optics and Precision Engineering
基金
Supported by the Major State Basic Research Program of China(Grant 2006CB300400)
the National Natural Science Foundation of China(Grant No .50775017)
关键词
天空偏振光
偏振光测量
斯托克斯矢量
偏振度
瑞利散射
skylight polarization
polarization measurement
Stokes vector
degree of polarization
Rayleigh scattering
