• How do I wrap my head around these things?
• My dataset is off the coast of Africa!
• My dataset looks like it's bigger than the Earth!
• My dataset is not located where it should be!
• What coordinate system should my dataset be in?
• My dataset is slightly offset from where it should be!
• How do I redefine a dataset's coordinate system?
• My measurements are bigger or smaller than they should be!
• Why is Mercator used if it's so distorted?
• Why don't we always use longitude/latitude?
• My X- and Y-values are OK, but my Z-values (heights, elevations) are off!
• What do all these terms mean?

I hate coordinate systems! How do I wrap my head around these things?

Apply this three-part mental model of geospatial datasets. Many common problems happen when one of these parts is missing or out of sync.

Attributes: the meanings or labels of a data point.

Coordinates: numbers describing the data point's position in space.

Coordinate (reference) system: metadata describing the space itself: origin, axes, units, etc.

For example:

Coordinate (reference) system: WGS84 longitude,latitude

I hate coordinate systems! My dataset is off the coast of Africa!