title: An evaluation of skylight polarization patterns for navigation.
abstract: Skylight polarization provides a significant navigation cue for certain polarization-sensitive animals. However, the precision of the angle of polarization (AOP) of skylight for vehicle orientation is not clear. An evaluation of AOP must be performed before it is utilized. This paper reports an evaluation of AOP of skylight by measuring the skylight polarization patterns of clear and cloudy skies using a full-sky imaging polarimetry system. AOP measurements of skylight are compared with the pattern calculated by the single-scattering Rayleigh model and these differences are quantified. The relationship between the degree of polarization (DOP) and the deviation of AOP of skylight is thoroughly studied. Based on these, a solar meridian extracted method is presented. The results of experiments reveal that the DOP is a key parameter to indicate the accuracy of AOP measurements, and all the output solar meridian orientations extracted by our method in both clear and cloudy skies can achieve a high accuracy for vehicle orientation.
authors.affiliation: College of Mechatronic Engineering and Automation, National University of Defense Technology, Changsha 410073, Hunan, China. tao_ma@live.com.
authors.forename: Tao
authors.initials: T
authors.lastname: Ma
authors.affiliation: College of Mechatronic Engineering and Automation, National University of Defense Technology, Changsha 410073, Hunan, China. xphu@nudt.edu.cn.
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Hu
authors.affiliation: College of Mechatronic Engineering and Automation, National University of Defense Technology, Changsha 410073, Hunan, China. lilian-zhang@hotmail.com.
authors.forename: Lilian
authors.initials: L
authors.lastname: Zhang
authors.affiliation: College of Mechatronic Engineering and Automation, National University of Defense Technology, Changsha 410073, Hunan, China. jx_Lian@hotmail.com.
authors.forename: Junxiang
authors.initials: J
authors.lastname: Lian
authors.affiliation: College of Mechatronic Engineering and Automation, National University of Defense Technology, Changsha 410073, Hunan, China. hexf_lit@126.com.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: He
authors.affiliation: College of Mechatronic Engineering and Automation, National University of Defense Technology, Changsha 410073, Hunan, China. yjwang@nudt.edu.cn.
authors.forename: Yujie
authors.initials: Y
authors.lastname: Wang
authors.affiliation: College of Mechatronic Engineering and Automation, National University of Defense Technology, Changsha 410073, Hunan, China. xianzw2011@163.com.
authors.forename: Zhiwen
authors.initials: Z
authors.lastname: Xian