What are Latitude and Longitude Coordinates?
Latitude and longitude “coordinates” are numeric values that describe the location of a “plot” or “point” on the earth, similar to how the X and Y coordinates describe the location of a point on a Cartesian graph.
For example, a Global Positioning System (GPS) device tracks its position by logging the geographic latitude and longitude coordinates, which can then be displayed on a map.
The “latitude” represents the value on the traditional Y axis, i.e., up/down or North/South.
The “longitude” represents the value on the traditional X axis, i.e., left/right or West/East.
Latitude and Longitude Formats (DMS & Decimal)
There are various different coordinate format systems. The traditional system is the Degrees-Minutes-Seconds (DMS) system, which looks something like:
40°39'16.95" N, 74°7'24.48" W (DMS)
This would be read as “40 Degrees, 39 Minutes and 16.95 Seconds North, 74 Degrees, 7 Minutes and 24.48 Seconds West”.
In the DMS format, the North / South / West / East directionality is identified by using the N, S, W, E letters.
Coordinates can also be represented in “Decimal Degrees” format which, as the name implies, uses metric decimal numbers to represent latitude and longitude. This is the preferred format, and this is also the primary format used by Google Maps.
For example, the above coordinates translate to the following in the decimal coordinates system:
40.65471, -74.12347 (Decimal Degree Coordinates).
In the Decimal format, the N, S, W, E directionality is identified by using positive and negative numbers. In the case of Google, North of the equator uses positive numbers (South of the equator uses negative numbers); East of the Prime Meridian uses positive numbers, while West of the Prime Meridian uses negative numbers.
It is also worth noting that some platforms – such as Google – use the format “latitude, longitude” (latitude first) while other platforms – such as ESRI – tend to use the format “longitude, latitude” (longitude first). This is something to be aware of when working with different platforms.
To learn more about plotting coordinates with the Map Maker, please see Plotting Latitude and Longitude Coordinates.