Recent advancements in fine spatial resolution remote sensing of night lights from space
ISBN 978-85-88783-11-9
Authors
1Levin, N.
1HEBREW UNIVERSITY OF JERUSALEM Email: noamlevin@mscc.huji.ac.il
Abstract
Night lights present a unique signature of human activity that can be seen and mapped from space. Resulting light pollution from artificial lights obscures the night sky for astronomy and has negative impacts on biodiversity as well as on human health. Remote sensing of night lights for mapping light pollution and global patterns of population and economic activity has been accomplished since the 1970s using the American DMSP/OLS sensor. However useful, these night lights images have several drawbacks, related to their coarse spatial resolution (3 km), overglow effects and saturation within urban areas. In recent years, several new sensors have been launched started offering medium and high spatial resolution night lights images. The VIIRS sensor onboard the Suomi-NPP satellite, launched in October 2011, acquires night lights images at a spatial resolution of 750 m, and has started offering global monthly mosaics of night lights from 2012 onwards. Comparisons of the DMSP/OLS and the VIIRS sensors, have shown the improved spatial and radiometric resolution of the VIIRS images. NASA and CONAE (Argentina) have jointly launched two satellites (SAC-C and SAC-D) that have a night-lights sensor at spatial resolutions of about 200-300 m, however their images are not easily available. Astronauts on-board the International Space Station (ISS), have been taking color night-time photos since 2003, and in 2011 an improved camera system has been installed on the ISS (known as the NightPod), improving the quality of ISS night lights images. ISS imagery offers a spatial resolution which is usually between 25-100 m, and although its acquisition is irregular, it has been shown that ISS night lights imagery can be useful for mapping demographic and socio-economic characteristics at the locality level. The finest spatial resolution space-borne sensor is the commercial Israeli EROS-B satellite, which since 2013 offers night lights images at a spatial resolution of 70 cm, comparable with night-time aerial photography. Urban land cover and land use can explain spatial patterns of night lights, with arterial roads and commercial and services areas being some of the brightest land use types. With the expansion of urban areas and technological developments in the lighting industry, continuous monitoring of artificial lights at medium and fine spatial resolution is of utmost importance to reduce the negative impacts of light pollution.
Keywords
Remote sensing; Night lights; Human activity