Black Marble Product
At night, satellite images of Earth capture a uniquely human signal--artificial lighting. Remotely-sensed lights at night provide a new data source for improving our understanding of interactions between human systems and the environment. NASA has developed the Black Marble, a daily calibrated, corrected, and validated product suite, so nightlight data can be used effectively for scientific observations. Black Marble is playing a vital role in research on light pollution, illegal fishing, fires, disaster impacts and recovery, and human settlements and associated energy infrastructures.
During processing, clouds have been removed, and atmospheric, terrain, vegetation, snow, lunar, and stray light effects on radiances have been corrected. The data is calibrated across time, validated against ground measurements, and includes quality indicators so that it can be used effectively for scientific observations. A detailed description of key algorithm enhancements can be found here
DNB imagery have a wide range of applications for a broad spectrum of data users. Along with their primary purpose of supporting the short-term weather prediction and disaster response communities, they also provide new data for tracking wildfires, gas flares, and light pollution, and have numerous socioeconomic uses, such as proxying economic activity, monitoring changes in energy infrastructure in urban areas, and providing a data to humanitarian organizations in conflict areas. A number of sources contribute to the DNB signal, including city lights, lightning, fishing fleet navigation lights, gas flares, lava flows, and even auroras. When partial to full illumination from the moon is available, reflection of this lunar illumination off of ice, snow, and other highly reflective surfaces enable the study of ocean and terrestrial features.
The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument is a component of the Suomi National Polar-orbiting Partnership (NPP) satellite. VIIRS consists of 22 spectral bands from the ultra-violet to the mid-infrared, one of which is able to observe nighttime lights, the day night band (DNB). DNB is a panchromatic band sensitive to visible and near-infrared wavelengths. Detailed design specs for VIIRS instrument can be found here.
The science behind Black Marble products:
