Background
The COVID-19 pandemic is currently bringing unprecedented impacts to every aspect of human life, from an individual level to local community, city, county, state, country, and global scales. Governments have imposed restrictions on human activity to help minimize the spread of the virus. The severity and level of enforcement of these restrictions have varied from city to city and country to country, and they range from no significant change in activities, to voluntary social distancing, all the way to full lockdown situations where entire populations are banned from leaving their homes.
One of the EO Dashboard efforts developed COVID-19 Slowdown Proxy Maps (SPM) and COVID-19 Recovery Proxy Maps (RPM) for 100 cities around the world utilizing ESA Sentinel-1 and JAXA ALOS-2 imagery to detect changes in human activity associated with COVID-19 closures/slowdown, as well as to track changes in human activity as economic activity begins to resume. The SPM/RPM products utilize synthetic-aperture radar (SAR) changes in coherency as a proxy to human activity (e.g., cars changing over in parking lots vs. empty/parked cars, new construction vs. unchanged land surface).
Objectives
Your challenge is to better understand societal trends in response to COVID-19 through the analysis of remote sensing data and products. These trends can vary across major urban environments, among cities, within countries, or globally. The SPM/RPM products have sufficient resolution to track changes in parking lots at shopping centers where businesses that were closed during the pandemic saw few cars parked outside, whereas grocery stores only saw a minor decrease in parking trends.
Your primary objective is to demonstrate how the social activities that can be observed with remote sensing data/products changed in response to COVID-19-related restrictions within regions, and/or in contrast to similar cities/urban regions around the world. An additional objective is to tie the trends identified in the SPM/RPM products with other products in the EO Dashboard, or other datasets that either provide a better understanding about the observed trends or show a linkage between specific trends, such as the decrease in automotive activity equating to the decrease in the amount of CO2.
Potential Considerations
- Black Marble High Definition (BMHD) Nighttime Lights: To monitor nighttime patterns at finer scales, use higher-level (Level 4) Black Marble High-Definition (BMHD) nighttime lights. Input layers include the NASA Black Marble standard product (VNP46A2), Landsat-derived normalized index products (NDVI and NDWI), and OpenStreetMap (OSM) derived road layers. The output is a synthetic nighttime lights image that maintains the Landsat spatial resolution. The increased level of detail provided by the BMHD allows users to visualize and differentiate different types of human activity patterns (e.g., residential, commercial, industrial sectors) at the characteristic scale of urban processes (≤ 30m). In this sense, the product can be used to monitor seasonal and long-term changes in cities while also enabling visual assessment of specific sectors impacted by abrupt changes, e.g., those caused by disturbances in power delivery. A full summary of methods and demonstration studies concerning the Black Marble HD can be found in Román et al., (2019).
- Black Marble High-Definition (BMHD) input ancillary data: 3 channels corresponding to moderate resolution base layers ancillary data to produce BMHD product. Datasets are scaled at 30m spatial resolution.
- File name prefix: “<cityname>_BMHD_Ancillary.tif”
- Number of Images: 8
- Scaled resolution: 30 x 30m
- Band 1: NDVI Layer
- Band 2: NDWI Layer
- Band 3: Road Layer
- Black Marble High-Definition (BMHD) output dataset: 1 channel corresponding to the scaled 0-255 intensity value at 30m spatial resolution.
- File name prefix: “<cityname><month><year>_BMHD_Scale.tif”
- Number of images: 15 images for each city (total 8 cities)
- Scaled resolution: 30 x 30m
- Data processing reference source: Link
- Black Marble Nighttime Lights Standard Product Suite for Suomi-NPP: NASA’s Black Marble represents a suite of two Nighttime Lights (NTL) products (VNP46A1 and VNP46A2) that offer vast improvements in sensor resolution and calibration over the previous era of Defense Meteorological Satellite Program/Operational Linescan System’s nighttime lights image products. Derived from the SNPP-VIIRS instrument’s Day-Night Band (DNB) sensor, the Top-of-Atmosphere (TOA-VNP46A1) and Lunar BRDF-Adjusted Nigttime Lights products (LBAN-VNP46A2) enable us to better monitor both the magnitude and signature of nighttime phenomena and anthropogenic sources of light emissions. The VNP46A1 product offers daily, top-of-atmosphere, at-sensor nighttime radiance, and the AVNP46A2 product provides data corrected for lunar bi-directional reflectance distribution function, atmospheric, thermal, terrain, and straylight effects. A full description of the products can be found in Román et al., (2018), and through: https://blackmarble.gsfc.nasa.gov/.
- Black Marble VNP46A1 and VNP46A2 dataset