Diverse relationships between Suomi-NPP VIIRS night-time light and multi-scale socioeconomic activity

Satellite-based observation of anthropogenic night-time light radiance is typically considered as a proxy measure for human spatial behaviour in terms of demographic and economic dynamics owing to quantitative connections between night-time light and socioeconomic activity. Most previous studies have focused on the monotonic response of artificial night-time lighting, primarily derived from the Defense Meteorological Satellite Programs (DMSP) with spatial resolution of 30 arc-seconds to socioeconomic variables at regional to county scales. Using ordinary least squares regression and quantile regression, we investigate the quantitative relationship between a finer resolution night-time light data than DMSP derived from the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi National Polar-orbiting Partnership satellite (Suomi-NPP) with spatial resolution of 15 arc-seconds and several demographic and economic factors across three local scales: county, district and sub-district in Xian City. Our results show diverse responses of night-time light radiance to multiscale socioeconomic variables: (1) monotonic relationship following linear or log-linear models is most likely to occur at the county scale, (2) various responses of the conditional quantiles of night-time lights to socioeconomic variables is highly prominent at both the district scale and the sub-district scale in association with non-monotonic relationship. Our findings may provide insight into the practical applications of fine resolution night-time imagery such as VIIRS data for quantitatively estimating human activity and socioeconomic dynamics at a fine scale.