Assessing the utility of DMSP/OLS night-time images for characterizing indian urbanization

Urbanization, that is the movement of population from rural to urban locations, is a process that has been occurring for hundreds of years, but is increasingly prevalent in today´s world. In 2008 most of the global population was resident in urban areas. It has been predicted that in the coming years, an increasing number of people will be living in cities; especially in the developing countries within in Asia and Latin America. This study considers the case of India, the second most populated country in the world, with a present total population exceeding 1 billion. It focuses on the state of Maharashtra (including the mega-city of Mumbai and its surrounds - the largest in India with a population of approximately 18.1 million). The Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS) is a spaceborne system that detects visible light and thermal emissions of the earth at night. The data is collected nightly, on a global basis. The aim of this paper is to correlate the values obtained from the radiance calibrated DMSP/OLS night-time images of 2001 with population data. The spatial resolution of DMSP/OLS images is approximately 1 Km. This paper asks the question over what range of spatial scales does DMSP/OLS have utility in retrieving metrics of urbanization.