By Alistina Shrestha
On February 12, 2025, a seminar on “Discover The World After Dark” hosted by the Remote Sensing and Geographic Information System (RSGIS) program at the School of Engineering and Technology (SET), AIT, captivated attendees with insights into satellite-derived nighttime lights research. It featured Dr. Christopher Elvidge, Director of the Earth Observation Group at Colorado School of Mines, United States, a pioneering figure with over three decades of experience. Dr. Elvidge pioneered the development of global satellite-derived nighttime lights and led the creation of a global dataset that has transformed research in biology, urban sciences, economics, and light pollution. With over 230 published papers and more than 37,000 citations, his groundbreaking work continues to inspire researchers worldwide.
Dr. Elvidge’s work has significantly shaped the development of global nighttime light data, utilizing the Defense Meteorological Satellite Program (DMSP) and the Visible Infrared Imaging Radiometer Suite (VIIRS) to advance urban studies, environmental monitoring, and our understanding of artificial illumination worldwide. Professor Nitin Kumar Tripathi and Dr. Sarawut Ninsawat, faculty members of the RSGIS program, attended the session and actively participated in discussions regarding the future of remote sensing technologies.
Dr. Elvidge explained how VIIRS, a satellite tool, captures images of the Earth at night, even in low-light conditions like moonlight. This technology helps us detect city lights, gas flares, industrial emissions, ships at sea, and wildfires. The Earth Observation Group (EOG), which processes the data from VIIRS, handles about 150 GB of nighttime data every day, providing valuable insights into human activities and environmental changes.
VIIRS data is used to track urban growth and economic activity, detect fires and heat from sources like gas flares, and monitor ship lights at sea. These insights are crucial for analyzing energy consumption, responding to disasters, and assessing environmental changes.
Dr. Elvidge demonstrated notable applications of VIIRS data, such as tracking the Lebanon power grid collapse (2021), monitoring light reductions in Kabul before the U.S. troop withdrawal (2021), and mapping wildfires in California for emergency response. The seminar also addressed ongoing research in nighttime remote sensing, including calibration methods, distinguishing artificial from natural light pollution, and exploring bioluminescence effects on maritime detection.
Prof. Nitin Kumar Tripathi and Dr. Sarawut Ninsawat discussed the future of VIIRS applications, NOAA’s ongoing initiatives, and the potential for tracking power failures during extreme weather events. As VIIRS technology evolves, its role in environmental monitoring, security, and disaster management will become even more critical.
Student feedback highlighted the seminar’s impact. Mr. Nikhil Shakya, a student from the RSGIS program, stated, “Informative, something new—beneficial information for design and urban development tracking.” Mr. Venkata Anantha Kiran Kona from AIT Extension remarked, “Dr. Christopher’s seminar on EOG’s night light data was insightful and engaging, marking his third presentation at our institute. His expertise and in-depth analysis provided a fresh perspective on night light data applications, demonstrating advancements in accuracy, monitoring, and real-world impact. It was a fantastic session, and I truly appreciated the opportunity to learn about these cutting-edge developments.”
