SQL and OpenStreetMap
SQL is a powerful coding language used with POSTGIS to analyze geographic databases. OpenStreetMap is an open source alternative to Google Maps, with geographic information volunteered by users.
Areas with more users, more internet infrastructure, and more government support for publicly available geographic information will be more thouroughly mapped that rural, poorly connected, and unsupported areas. For Dar Es Salaam, this means that the inner city is well mapped, while the outer suburbs are less accurately mapped. The city was mapped with drone technology during (x period of time) by (x org that did it). Accuracy can be checked by switching between OpenStreetMap and Google’s satalite view. One problem with many volunteered data sources is that the sources may not agree on a category or designation for an object. This came up multiple times in class over the designation of roads. Drone imaging, while capturing an accurate polygon map of the city, could not put in information like speed limits and road names, leaving that up to users. I attempted to accommodate for all of these factors in my analysis of ambulance access.