Why we don't need to worry Map projections are vitally important for cartographers concerned with representing large areas of the Earth's surface owing to the distortion problem and the myriad choices and compromises available in various projections and their numerous specialized, modified forms. However, there is the possibility that analysts will deal with maps with different projections and that those maps will not fit properly when brought together. Streets and boundaries would be misaligned and structures misplaced. However, this misalignment can also occur for reasons unconnected with projection, as explained below. Although crime analysts do not need to worry about projections per se, a related issue, coordinate systems, generally needs to be given more attention because the analyst probably will encounter incompatible coordinate systems.
Projections determine how the latitude and longitude grid of the Earth is represented on flat paper.
For example, latitude and longitude together are a coordinate system based on angular measurements on the Earth's sphere. But there are other ways of referring to points. For instance, all measurements could be based on distances in meters and compass directions with respect to city hall. That would also be a coordinate system. Distances in feet and directions could be based on the police chief's office as a reference point.