UNKNOWN

According to the United Nations (UN) report, approximately 54% of the world's population lives in the urban region as of 2014 and the trend is expected to rise to 66% by 2050. India along with China and Nigeria are expected to contribute to 37% of growth of world's urban population. UN reports that managing the rapid urbanization for sustainable development is one of the key challenges of the 21st century (United Nations, 2014). Globally, governments of both developed and developing nations are embracing the con- cept of smart cities for improving the quality of life of urban population through a sustainable development (Caragliu et al., 2011; Batty et al., 2012). Smart city is an integration of infor- mation and communication technologies to manage the various assets of urban infrastructure. This will lead to improved governance leading to sustainable economic development. Precise mapping of urban infrastructure is one of the key requirements for an integrated vir- tual urban utility platform. Over the years, geospatial technologies have proved to be valuable for mapping both human-made and natural resources (Paparoditis et al., 1998; Mayer, 1999; Wulder and Franklin, 2006). Exhaustive 3D (three dimensional) mapping of urban environ- ment has been made possible using very high resolution satellite images, aerial photographs, maps, as well as data from traditional topographic surveys (Suveg and Vosselman, 2004; Jin and Davis, 2005; Luhmann et al., 2014; Haala et al., 2015).