Sciences and Exploration Directorate

Ranjay M Shrestha

(Senior Research Scientist)

Ranjay M Shrestha's Contact Card & Information.
Phone: 301.614.6882
Org Code: 619
Mail Code 619
Greenbelt, MD 20771


Ph.D. - Earth Systems and Geoinformation Sciences, George Mason University, Fairfax, VA
M.S. - Geographic and Cartographic Sciences, George Mason University, Fairfax, VA 
B.S. - Computer Science/Geography Information Science, University of Idaho, Moscow, ID


2019 SSAI Performance Award

2017 The Sixth International Conference on Agro-Geoinformatics - Winner of Best student paper competition

2013 EarthServer Innovation Award, rasdaman, Germany

Talks, Presentations and Posters


YTD Highlights


  • Ranjay Shrestha (619/SSAI) gave a poster presentation titled "NASA’s Black Marble Nighttime Lights Product Suite" at the 12th Annual Science & Exploration Directorate New Year's Poster Party on Feb 26th, 2019

YTD Highlights


  • Ranjay Shrestha (619/SSAI) attended the AGU Fall meeting, December 10-14, 2018 in Washington D.C., and gave a poster presentation entitled “NASA’s Black Marble Nighttime Lights Product Suite”. The presentation introduced the upcoming suite of nighttime lights products derived with the improved algorithm that produces high-level science quality cloud-free daily nighttime light (NTL) imagery. The corrected nighttime radiances, resulting in a superior retrieval of nighttime lights at short time scales and a reduction in background noise, enable quantitative analyses of daily, seasonal and annual variations. Some recent applications include: (i) measuring the effects of Hurricane Maria on Puerto Rico’s energy sector, (ii) monitoring the effects of conflict and population displacement in Syria, (iii) monitoring the impact of the recent Hurricanes (Florence and Michael) in the U.S.
  • Ranjay Shrestha (619/SSAI) attended the 5th International Conference On Artificial Light at Night (ALAN 2018), November 12-14, 2018 in Salt Lake City, Utah, and gave an oral presentation entitled “NASA’s Black Marble Nighttime Lights Product Suite”. The presentation introduced the new NASA's Black Marble nighttime lights product suite (VNP46) retrieved from the Visible Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB) onboard the Suomi National Polar-orbiting Platform (SNPP) to the ALAN community. The talk also gave an update on the validation activities of the product under the Group on Earth Observations (GEO) Human Planet Initiative. The product validation activities, conducted in partnership with Puerto Rico's Working Group on Light Pollution (PRWGLP), include the use of in-situ NTL measurements at the Pitahaya Farmland site in Cabo Rojo, Puerto Rico. Some of recent applications of the product were also showcased in the talk including: (i) measuring the impacts of Hurricane Maria on Puerto Rico’s energy sector, (ii) monitoring the effects of conflict and population displacement across Syria, (iii) assessing the effectiveness of rural electrification program in developing nation, (iv) monitoring the impacts of Hurricane Michael across neighborhoods in Florida.
  • NASA’s Black Marble team members Miguel Román (619), Ranjay Shrestha (619/SSAI), Zhuosen Wang (619/UMD), Eleanor Stokes (619/UMD), and Tian Yao (619/SSAI) participated in the MODIS/VIIRS Science Team Meeting, October 15 – 19 in Silver Spring.

Selected Public Outreach

YTD Highlights

2019 - Present

  • NASA's Black Marble Products (GSFC/619) were utilized to monitor the impact of Cyclone Idai in Mozambique, in response to the requests from the Department of State, and the International Federation of Red Cross and Red Crescent Societies (IFRC). The power outage maps generated using the product helped disaster response efforts in the short-term as well as long-term monitoring during the crucial stages of disaster recovery. The HD products helped identify the widespread impact of the cyclone in electric grids within the neighborhood level, whereas the standard products provided the outage maps at the regional level.
  • Google Arts and Culture showcased work from NASA’s Black Marble team in an interactive exhibit called "Satellite Images of the Earth at Night”. The exhibit, using Black Marble nightlight images, highlights how images of the world at night can reveal information about wildfires, fishing boats, holiday activity patterns, electrification, and disaster impacts and response.
  •  Media coverage in Forbes, Gizmodo, and Physicsworld discuss the Black Marble Science team's work monitoring power outages and electricity restoration in Puerto Rico after Hurricane Maria.

YTD Highlights

February 2018 - 2018

  • NASA’s Black Marble product suite (GSFC/619) was utilized to monitor the impact of hurricane Florence and Michael were monitored throughout the duration of the landfall. The Black Marble products were processed daily, and used by the NASA disaster team to assess disruptions in energy infrastructure and utility services following the hurricanes by comparing pre- and post-event imagery. The Black Marble HD product to monitor the impact of Hurricane Michael through power outages was also featured as the “Image of the Day” in the NASA’s earth observatory.
  • The NASA Black Marble product suite (GSFC/619) was used to assess disruptions in energy infrastructure and utility services following the California wildfire in Fall 2018. The pre- and post-event mapping and montoring of power outages using the HD products were dissminated through NASA Disaster Portal.
  • The latest readership statistics from Google showed that the “Earth at Night” (619) is the most popular of all Google Earth stories. The NASA stories in Google Earth have been viewed over 2.3 million times since April 2017, and the “Earth at Night” story has contributed over 40% of the viewership and is expected to hit the one million views mark soon. The story, using the 2016 global composite nightlight image, through five major spots of the world – Tokyo (Japan), The Nile (Egypt), New Delhi (India), New York (USA), and Hong Kong (China) provides a glimpse of what the world looks from space at night.
  • NASA’s Black Marble product suite (GSFC/619) was featured in the Bloomberg Businessweek article titled “All the Things Satellites Can Now See From Space” published on July 26, 2018. The article aimed to highlight some of the recent remote sensing applications by companies, government agencies, and NGO’s enabled by a new generation of satellites. The specific piece, written by Andre Tarar, featured a NASA study on measuring the effects of Hurricane Maria in Puerto Rico using the Black Marble product. The article accentuated the significance of the effort by the GSFC team to understand and measure the accuracy of Suomi NPP imagery through in situ measurements in producing the Black Marble product to capture the nighttime image more accurately. With improvements such as filtering out the nonelectric light, the result produced a powerful set of before-and-after images that revealed the devastating extent of power outages and other infrastructure damages post-hurricane Maria.
  • NASA’s Black Marble (GSFC/619) was featured in the released draft Recovery plan titled “Transformation and Innovation in the Wake of Devastation: An Economic and Disaster Recovery Plan for Puerto Rico” produced by the Puerto Rico government. This recovery plan was developed in response to the “Further Additional Supplemental Appropriation for Disaster Relief Requirements Act, 2018” (Public Law No. 115-123) after the catastrophic damages by Hurricane Irma and Maria in 2017; and the devastating effects on people’s health, safety, and critical infrastructure. The document considered the loss of power and destruction to the electricity grid the most damaging consequences for critical infrastructure resulting in the failure of the entire network and communication systems. Through the Black Marble, areas with significant and prolonged power disturbance were identified and the emergency response as well as short- and long-term recovery plans were staged to restore the power.
  • A contributing article between BBC Arabia and NASA’s Black Marble science team (619), entitled “Syria from Space”, was recently nominated for the prestigious One World Media award under their ‘Best Media’ category. Established in 1988, the One World Media awards recognize the best media coverage of the developing world, reflecting the social, political and cultural life of people around the globe. The awards, to be announced at the British Academy of Film and Television Arts (BAFTA) later in June, highlight the unique role of journalists and filmmakers in bridging the divide between cultures worldwide and raising awareness of underreported issues and stories.
  • An article in The Economist magazine (April, 2018) featured work from NASA’s Black Marble Science Team (619) following the recovery of Puerto Rico’s energy sector six months after Hurricane Maria struck the US Territory.