LPTMM
Speakers
Key speakers :
Assoc. Prof. Dr. Alexander Wilkie
Computer Graphics Group, KSVI, MFF UK
Carles University in Prague, Czech Republic
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Title:
Skylight models in realistic computer graphics
Abstract:
In the past decades, photorealistic computer graphics has made huge advances, and now offers a sophisticated technology stack for both entertainment and visual planning and prediction purposes. The appearance of most virtual scenes and objects can now be predicted to high levels of accuracy, although some types of scenes still pose challenges. One such class of scenes are outdoor environments, where the main issues lie in two areas:
the still rather high computational effort needed to obtain highly accurate solutions, and the modelling of realistic atmospheric conditions. In my talk, I will give an overview of the current state of the art in this area of graphics, and discuss possible connections of this technology to light pollution calculations.
Prof. Dr. Noam Levin
Department of Geography, Hebrew University of Jerusalem &
Remote Sensing Research Centre, School of the Environment,
The University of Queensland
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Title:
Remote sensing of night lights: overview of current sensors and challenges
Abstract:
Remote sensing of night lights in the visible band allows us to directly observe humans from space, serving as a proxy for monitoring the dynamics of population and economic activities. Historically, the development of sensors for monitoring night lights has lagged behind ‘traditional’ optical day-time remote sensing and night-time thermal remote sensing. In my talk I will present the current state of the major space-borne and ground-based sensors used for remote sensing of night lights. In addition, I will review some of the challenges which are unique to remote sensing of night lights, which include anisotropic properties of light emission, high temporal variability, and the transition to LED lighting technologies – all of which highlight the need for a new generation of space borne night lights instruments.
Assist. Prof. Brett Seymoure, PhD
Department of Biological Sciences
University of Texas at El Paso
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Title:
Attempting to untangle the effects of skyglow and direct lighting on arthropod behavior and vision
Abstract:
Organisms time daily behaviors (e.g. foraging, resting, predator-avoidance, etc.) and seasonal phenology (e.g. reproduction, parental care, blooming, etc.) using consistent daily changes in light intensity resulting from solar and lunar altitudinal changes. These natural light cues, which have been constant for millennia, are now under threat due to artificial light at night (ALAN). ALAN disrupts natural light cycles through direct lighting (i.e. glare) and atmospheric scattering of light (hereafter skyglow). Although much work has demonstrated the consequences of direct lighting on organisms, limited research exists on how and why skyglow impacts organism and ecosystem health. We first introduce how skyglow alone increases ambient intensity of light levels and review
literature on impacts of increased light level intensities on organismal biology. Then we report on two ongoing projects: 1) altered foraging and behavior in wolf spiders under increased diffuse lighting conditions similar to skyglow levels; and 2) the interaction of skyglow, direct light sources, and lunar cycles on moth mate-locating behaviors. For the first project: wolf spiders primarily hunt prey and avoid predators using visual cues, as well as vibratory cues. Many wolf spiders are nocturnal, and their circadian rhythms are highly dependent upon light entrainment. Furthermore, wolf spiders have cosmopolitan distributions that spread from highly urbanized to rural environments. To investigate how altered light levels at night affect spider foraging behavior, we collected approximately 100 wolf spiders, Rabidosa rabida, from a rural site in Missouri, USA. For five weeks we exposed spiders to different light treatments at night: natural lunar cycle, consistent starlight conditions (~0.001 lux), perpetual quarter moon conditions (~0.01 lux), perpetual full moon (~0.1 lux), and perpetual nautical twilight (~1.0 lux). Spiders underwent a foraging assay where they were able to prey upon four wingless fruit flies in 15 minutes. We tracked the movement of both spiders and fly prey to quantify how spider movement and foraging are altered under different lighting conditions.
For the second project, sphingid moths, (i.e. hummingbird moths), are long-flying, nocturnal insects that are important pollinators in many ecosystems. Unfortunately, sphingid moths are highly attracted to artificial light at night. Sphingids have been shown to navigate across
the landscape using a dorsal light response that likely evolved to utilize the moon as a landmark. Although research is showing how sphingid moths, navigate under different extremes of ALAN, the interactions between natural conditions and ALAN concerning flight remain to be investigated. First, we tested how moths navigate under differing lunar conditions (lunar phase and lunar altitude), and then direct light sources and skyglow. Here, we show preliminary results of how these three factors (lunar conditions, direct light sources, and skyglow) interact to alter moth flight behaviors.
We conclude with pressing questions on how to accurately quantify biologically relevant differences between skyglow and direct light sources, as well as how to properly recreate experimental conditions that match skyglow resulting from urban areas.
