Researchers at NASA’s Goddard Space Flight Center (GSFC) and the Universities Space Research Association (USRA) have observed changes in light usage around Ukraine since January 2022. lights in March, electricity has slowly recovered and regular human activity has seemed to pick up in many parts of the country, especially around the capital.

The Visible Infrared Imaging Radiometer Suite The Finland NPP satellite (VIIRS) measures night light emissions and reflections through its day-night band. With this recognition capability, it is possible to distinguish the intensity of light on the earth’s surface and how they change.

“It is usually difficult to get information about conflict areas, which makes satellite imagery quite powerful. These data show us one dimension of how the effects of the conflict have been distributed within Ukraine, “said Eleanor Stokes, a USRA researcher and second director. Black marble project. “In the short term, the data will be useful to humanitarian organizations because they provide estimates of where and how many people have lost access to basic services, exacerbating the loss of human lives.”

“In the longer term, researchers will use this information to understand how conflicts have affected development and the economy,” Stokes added. “Black marble is also a special way to track conflict recovery because lights usually follow people. We have worked with organizations such as the Internal Displacement Monitoring Center to help assess where displaced people are most likely to have fled and to monitor their return home.

The maps at the top of this page show the night lights in Kiev, Ukraine throughout March and May 2022. Ranjay Shrestha (NASA GSFC) and the Black Marble team selected the best cloudless nights of each month and then processed. and analyze VIIRS data to produce combinations of night lights. The information on the lights is placed on top of the floor map that has been built Landsat 9 near-infrared observations (lane 5) that help distinguish the built environment from the natural one. The third image above is a composite image of the light of the area in January 2022, before the start of the war. The animation below shows the changes across the country in January-May 2022.

“During the first months of the war, electricity and basic services were attacked in several major cities,” Stokes said. “As the war continued into May, we saw a change – some disappearance of lights in eastern Ukraine and some recovery in western Ukraine. Black Marble HD images show a recovery, especially in the suburbs of Kiev, when residents returned to the capital.

Power plants and other infrastructure were systematically damaged in the early weeks of the war, cutting off electricity from millions of people. Some of the outdoor lighting has also been intentionally dimmed, removed or turned off, pointed out Sergii Skakun, a researcher at the University of Maryland who grew up in Ukraine and has studied night lights in the area. By in the media, crews have since been able to rehabilitate substations and high – voltage lines in some parts of Ukraine. However, many areas are left without significant night lighting – perhaps due to a lack of power or perhaps deliberate choices to keep the lights off.

International organizations, such as the United Nations Institute for Training and Research’s Operational Satellite Applications Program (UNITAR-UNOSAT), use night photographs to monitor conflicts. Night scenes also help relief and peacekeeping teams identify areas that need help and support the most.

Accuracy is critical in studies with night lights. Unprocessed images can be misleading, as moonlight, clouds, air pollution, snow cover, seasonal vegetation – even the location of the satellite – can alter the reflection of light. The Black Marble research team calibrates its measurements to take into account changes in the phase of the landscape, atmosphere, and moon, and to filter out stray light from sources other than electric lights.

Joshua Stevens NASA Earth Observatory images using Black Marble data courtesy of Ranjay Shresthan / NASA Goddard Space Flight Center. The story of Michael Carlowicz.