DMSP/OLS night‐time light imagery for urban population estimates in the Brazilian Amazon

Abstract

This article analyses DMSP/OLS night‐time imagery as an information source to detect human settlements and to estimate the urban population in the Amazon region. DMSP/OLS single orbits were used to generate a DMSP stable light mosaic for 2002, in which most of the urban settlements with a population higher than 5000 inhabitants were precisely identified. DMSP/OLS night‐time mosaic images from 1995, 1999 and 2002 were integrated with the IBGE census data and the correlation between DMSP/OLS night‐time light area and the urban population was compared. Coefficients of determination higher than 0.8 were obtained from the linear regression between DMSP/OLS night‐time lights and urban population census data. Although the fieldwork showed that DMSP image data could only record urbanized settlements with more than 2.5 km² of well‐lit surface areas, the initial and final extension of the night‐time light foci were actually precisely registered. Therefore, this paper identifies the potential of DMSP night‐time light images for estimating urban population as well as the technical limitations of using such images as a means to monitor urban population dynamics annually in a region where data are scarce and the demographic dynamics are unique, as in the Brazilian Amazon.