Mapping urban structure and spatial connectivity with VIIRS and OLS night light imagery

Stable night lights imaged by the VIIRS instrument on the NASA/NOAA Suomi NPP satellite provides higher spatial resolution and greater dynamic range than DMSP-OLS night light data. We use coregistered OLS and VIIRS night light composites collected in April 2012 to map night lights from a wide variety of settlements in Brazil, India, China and the USA. Color composites of VIIRS and OLS brightness data with Log₁₀VIIRS filtered brightness clearly show the benefits of VIIRS higher spatial resolution and greater dynamic range. Intra-urban variations in brightness are detected by VIIRS in urban cores saturated in the OLS imagery. VIIRS is also able to distinguish small point sources of light at scales approaching 1 km where OLS registers only low luminance background light often indistinguishable from overglow. Comparison of power spectral density estimates of VIIRS and OLS transects show that VIIRS resolves ~10 dB more signal than OLS at scales finer than 70 km. This difference is apparent in VIIRS ability to resolve roads and small villages interconnecting vast spatial networks of larger settlements observed with OLS.