A Coordinate Reference System (CRS) is a framework used to define how spatial data is mapped and interpreted in terms of geographical or planar coordinates.

It allows for the precise location of geographical features on the Earth's surface or on a plane, enabling the consistent and accurate measurement of spatial data.

There are 2 types of CRS:

  1. Geographic Coordinate Systems: These are based on a three-dimensional spherical surface and use latitude and longitude to specify locations. This is commonly used for GPS coordinates (latitude, longitude, altitude); and most of the time, the GPS coordinate we’ll manipulate are expressed in WGS84.
  2. Projected Coordinate Systems: These systems project the three-dimensional surface of the Earth onto a two-dimensional plane, typically using a map projection. This is usually the type of coordinate system we are used to work in: our maps are usually expressed in such a coordinate system.

EPSG

The EPSG (European Petroleum Survey Group) is a widely used database of CRS definitions, each identified by an EPSG code. The EPSG.io website may help you to find the proper EPSG code for a specific CRS.

Universal Transverse Mercator (UTM)

The Universal Transverse Mercator (UTM) is a global map projection system that provides a practical way to map large regions of the Earth's surface. In the UTM, the Earth is divided into 60 zones, numbered from 1 to 60. Each zone is further divided into latitude bands, usually 2 (N for north and and S for south).

This website will help you to visualize which UTM zone you are in.

How to get the EPSG code for the corresponding the UTM zone?

If the UTM code is:

To get the EPSG code, you then have to append the UTM zone number.

For example: