Evaluating Saturation Correction Methods for DMSP/OLS Nighttime Light Data: A Case Study from China’s Cities

Abstract

Remotely sensed nighttime lights (NTL) datasets derived from the Defense Meteorological Satellite Program's Operational Linescan System (DMSP/OLS) have been identified as a good indicator of the urbanization process and have been widely used to study such demographic and economic variables as population distribution and density, electricity consumption, and carbon emission. However, one issue must be considered in the application of NTL data, i.e., saturation in the bright cores of urban centers. In this study, we evaluate four correction methods in China's cities: the linear regression model and the cubic regression model at the regional level, and the Human Settlement Index (HSI) and the Vegetation Adjusted NTL Urban Index (VANUI) at a pixel level. The results suggest that both correction methods at the regional level improve the correlation between NTL data and socioeconomic variables. However, since the methods can only be used on saturated pixels, the correction effects are limited, as the saturated area in Chinese cities is rather small. HSI and VANUI increase the inter-urban variability within certain cities, OPEN ACCESSRemote Sens. 2014, 6 9854 especially when their vegetation health and abundance is negatively correlated with NTL. However, the indices may induce bias when applied in a large region with a diverse natural environment and vegetation, and the application of HSI with a relatively high sensitivity of HSI to NDVI may be limited as NTL approaches maximum. Proper methods for reducing saturation effects should thus vary with different study areas and research purposes.

Evaluating the Use of DMSP/OLS Nighttime Light Imagery in Predicting PM2.5 Concentrations in the Northeastern United States

“…The results are in line with other recent studies [52][53][54], which all indicated that land use information such as NDVI can help to predict the PM 2.5 concentration.…”

Correlations between Urbanization and Vegetation Degradation across the World’s Metropolises Using DMSP/OLS Nighttime Light Data

“…First, the spatial resolution of the VIP data set limits the study to focusing on big metropolises rather than small cities. Second, the limitations from coarse resolution and the spillover effect indicate that the accuracy of urbanization information extracted using NTL data requires further improvement [61][62][63]. The new NPP-VIIRS data, which has overcome the relatively low spatial resolution, the lack of onboard calibration and the pixel saturation issue in DMSP/OLS data, is recommended for obtaining higher-quality urbanization information [64].…”

Multi-Scale Measurement of Regional Inequality in Mainland China during 2005–2010 Using DMSP/OLS Night Light Imagery and Population Density Grid Data

“…To avoid radiometric problems such as over-saturation that occurs in urban centers [64,65], we used the radiance calibrated product. Compared to the traditional DMSP/OLS stable products [66], the radiance calibrated product provides much better radiometric attributes so that it quantifies the actual night light more accurately.…”