Reference Systems for Urban Mobility

Abstract

In the study of urban mobility, understanding the contribution of geospatial data and the relevant geospatial technologies associated with the collection, storage, and manipulation of geo-referenced data is essential. Correct understanding of the reference frames used for the collection of geospatial data ensures that the integrity and accuracy of the data collected is maintained, keeping in mind the surveying principle, ‘whole to part’. It also ensures that the errors involved in the collection of data are well within the accuracy range expected for the particular scale of mapping, which may then be used for computations of distance or area. Geospatial data is collected in a three-dimensional space and is converted to a two-dimensional space for many practical applications. A large range of map projections are available for this conversion which, again, maintain different cartographic properties for any specific application. The Universal Transverse Mercator (UTM) is one such projection, which has properties that come in handy for our problem of mapping for urban mobility. Global Navigation Satellite Systems (GNSS) and their integration with cellular network infrastructure have caught the imagination of people and served as the inspiration for a wide spread of applications such as automatic vehicle location, tracking systems, navigation, pedestrian navigation systems, intelligent transportation Systems, and precise positioning of emergency callers, all using a location in some reference system.