Results 31 to 40 of about 41,435 (217)
Orientation with a Viking sun-compass, a shadow-stick, and two calcite sunstones under various weather conditions. [PDF]
, 2013 It is widely accepted that Vikings used sun-compasses to derive true directions from the cast shadow of a gnomon. It has been hypothesized that when a cast shadow was not formed, Viking navigators relied on crude skylight polarimetry with the aid of ...
Barta +20 more
core +1 more source
The polarization patterns of skylight reflected off wave water surface
Optics Express, 2013 In this paper we propose a model to understand the polarization patterns of skylight when reflected off the surface of waves. The semi-empirical Rayleigh model is used to analyze the polarization of scattered skylight; the Harrison and Coombes model is used to analyze light radiance distribution; and the Cox-Munk model and Mueller matrix are used to ...
Zhou, Guanhua +3 more
openaire +3 more sources
IEEE Access, 2020 The migratory animals are capable of traveling long distances by fusing varied information, such as the halteres, the star positions, and the polarization pattern.
Qingyun Zhang +3 more
doaj +1 more source
Polarization singularities from unfolding an optical vortex through a birefringent crystal [PDF]
, 2004 Optical vortices (nodal lines and phase singularities) are the generic singularities of scalar optics but are unstable in vector optics. We investigate experimentally and theoretically the unfolding of a uniformly polarized optical vortex beam on ...
Flossmann, Florian +3 more
core +3 more sources
Bio-Inspired Polarized Skylight-Based Navigation Sensors: A Review
Sensors, 2012 Animal senses cover a broad range of signal types and signal bandwidths and have inspired various sensors and bioinstrumentation devices for biological and medical applications.
S. Zaleha M. Diah +2 more
doaj +1 more source
Frontiers in Behavioral Neuroscience, 2017 Central place foragers are faced with the challenge to learn the position of their nest entrance in its surroundings, in order to find their way back home every time they go out to search for food.
Robin Grob +4 more
doaj +1 more source
Sensors, 2014 Navigation plays a vital role in our daily life. As traditional and commonly used navigation technologies, Inertial Navigation System (INS) and Global Navigation Satellite System (GNSS) can provide accurate location information, but suffer from the ...
Zhiwen Xian +6 more
doaj +1 more source
Specialized ommatidia of the polarization-sensitive dorsal rim area in the eye of monarch butterflies have non-functional reflecting tapeta [PDF]
, 2009 Many insects exploit sky light polarization for navigation or cruising-course control. The detection of polarized sky light is mediated by the ommatidia of a small specialized part of the compound eye: the dorsal rim area (DRA).
Thomas Labhart +2 more
core +2 more sources
A Bionic Camera-Based Polarization Navigation Sensor
Sensors, 2014 Navigation and positioning technology is closely related to our routine life activities, from travel to aerospace. Recently it has been found that Cataglyphis (a kind of desert ant) is able to detect the polarization direction of skylight and navigate ...
Daobin Wang +3 more
doaj +1 more source
Processing of sky compass cues and wide-field motion in the central complex of the desert locust (Schistocerca gregaria) [PDF]
, 2018 1. Polarization-sensitive neurons of the locust central complex show azimuthdependent responses to unpolarized light spots. This suggests that direct sunlight supports the sky polarization compass in this brain area. / 2.
Pegel, Uta
core +1 more source