Talk to the experts: Aline Leite
Aline has a Master degree in Transportation Engineering and a Bachelor degree in Geography, she also has a specialization in Urban Engineering. She has experience in Transportation using GPS and GIS. She has been working with Public Transportation for more than three years acting mainly in urban and road transport planning using Geographic Information Systems (GIS). Currently she is working as a Transportation Specialist at the Union of Bus Companies of the city of Rio de Janeiro /Rio Buses - Brazil.
Amanda - Aline, can you explain us what is georeferencing and what are its main uses?
Aline - Geoprocessing is georeferenced data processing, using computational and mathematical techniques to treat geographic information. These techniques allow you to do complex analyzes and integrate data from multiple sources, creating a database. The computational tools are known as Geographic Information Systems - GIS. Geoprocessing is an interdisciplinary technology that allows the convergence of different scientific disciplines for the study of environmental and urban phenomena. There are highly qualified professionals in Geoprocessing with different academic backgrounds.
Amanda - How georeferencing can be applied in transportation area? Can you give us some examples?
Aline - As I said, geoprocessing is a technology that can be used by different areas. In transportation, for example, we can create origin-destination matrices using georeferenced data, identify priority areas with greater demand volume for public transportation or for use of private vehicles, define the best route to be used for product displacement and roterization. We can also combine geographic analysis of thematic maps with a transport network of a certain region to define these routes.
Amanda - I would like to know what are the main softwares or tools that professionals that intend to work in transportation area with georreferenced data must know. Could you please name a few?
Aline - There is a great range of software of Geographic Information Systems what can make the process of choosing a GIS software for a project an arduous task. Besides, it may be also necessary to combine two or more software in order to reach your desired goals. There is no software more suitable for one project, and it is not possible to say that a certain software is better than another. The choice depends on the type of project or the outcome that is expected. Some of the software mostly used are: Kosmo, gvSIG, Quantum GIS, ArcGIS, MapInfo, GRASS, Maptitude Mapping Software, TransCAD Transportation Planning Software, TransModeler Traffic Simulation Software or TransModeler SE Traffic Analysis Software.
Amanda - We know that georeferenced data can be collected with different types of GPS. Among the devices, is there any that is more suitable for use in the transportation area? What are the basic differences between the types of GPS (vehicular, topographic, geodesic)?
Aline - I believe that just as the choice of an ideal software for geoprocessing depends on the type of work to be developed, the same goes for the use of GPS.The accuracy of the results to be achieved is what will determine the ideal GPS for the required application. The Global Positioning System (GPS) is a satellite positioning system that provides a mobile receiver with its position as long as the receiver can be reach by GPS satellites (four or more for greater accuracy). The differentiation between these categories is mainly due to the accuracy that can be given by the equipment and real positioning data that can be captured in it. The most accurate ones, that give values in millimeters, are the Geodetic receivers. The Topographic GPS has similar characteristics of the Geodetic one and also has high precision, usually giving a position with centimeters of accuracy in the measurement. Both categories have technical applications, and proprietary features such as post-processing, what means they generally do not report positioning instantly. In the case of the category of greater use, the Navigation GPS, although it has less precision of positioning, has numerous advantages like the low acquisition price and numerous applications.
Amanda - Finally, I would like to know, what other ways do researchers or professionals commonly use to collect georeferenced data in transportation, others than GPS?
Aline - The most important thing to be considered in an analysis using geoprocessing is the quality of the analysis produced with the georeferenced data, otherwise the researcher or technician will only be extracting, collecting and producing thematic maps without a real critical analysis of what they intend to demonstrate. Drones, satellite images, geographic database of federal, municipal institutions can provide data for a project focused on transportation.