However, health and environmental rationales [3] for changes in lighting may also play a role in lighting decisions. A recent manifestation in the long history of energy-based transformation in scientific study Inhibitors,Modulators,Libraries lighting has already started, with more than a billion incandescent light bulbs having been replaced by CFLs over the past decade. Over the long term, LEDs have the potential to become the predominant lighting type because of their continuing development towards extremely low energy consumption, long life, and color variability [4]. In addition, there is a synergism between implementation of renewable power generation systems and the installation of low power LED lighting that can be powered by locally generated wind and solar power [2].

The detection of lights from space has been possible with data from the Defense Meteorological Satellite Program (DMSP) since the early 1970s Inhibitors,Modulators,Libraries [5]. While global in extent, the DMSP collects low light imaging data in a single spectral band straddling the Inhibitors,Modulators,Libraries visible and near infrared (NIR), making it impossible to discriminate lighting types or the spectral quality of lights. In addition, DMSP nighttime lights are acquired at coarse spatial resolution (2.7 km2) with six bit quantitization and no on-board calibration. The DMSP sensor is typically operated at high gain setting for the detection of moonlit clouds. As a result, the signal often Inhibitors,Modulators,Libraries saturates on bright urban cores. Despite these flaws, a diverse set of global applications have been developed for DMSP nighttime lights ranging from estimation of light pollution levels [6], constructed surface densities [7], population distribution [8], poverty rates [9], electrification rates [10], and estimates of resource consumption rates [11].

Based on the shortcomings of DMSP nighttime lights Elvidge and others developed a Nightsat mission concept [12,13], which outlines the spatial resolution, spectral band options, overpass time and repeat cycle considerations for future satellite sensors capable of collecting global nighttime lights for use in a variety of social, energy and environmental Dacomitinib applications. Key recommendations for Nightsat include a spatial resolution in the range of 50 meters, multiple spectral bands for the discrimination of lighting types, and a repeatable in-flight radiance calibration procedure.

The Nightsat papers recommended inclusion of the photopic [14] and scotopic [15] human visual sensitivity bands based on the fact that these are widely used by the lighting engineering community. In phosphatase inhibitor particular, lighting systems are designed to provide specific brightness levels in the photopic band for different types of human activities. However, the recommendation to include the photopic and scotopic spectral bands on Nightsat had not been based on evidence that these spectral bands were useful in discriminating lighting type or character.