Something GISsy

What is linear referencing?

Linear referencing is a term thrown around in GIS, especially when describing (you guessed it) linear features.

Why use linear referencing?

Imagine whilst driving from Brisbane to Sydney (887 km) you had to describe a location as 31°36’52.3″S 152°43’40.1″E. Where would you think this was? Not easy without a map or GPS. What if the location was presented as 539 km from Brisbane? Without even looking at a map you know that this location is closer to Sydney than Brisbane. That is one example of why linear referencing is used: simplification of location description.

In the field, marker posts are often placed during the construction of lineal assets such as pipelines to enable field crews to identify locations quickly without GPS equipment or map reading. Power lines, railways, roads and pipelines are good examples of where linear referencing is traditionally used.

Linear referencing is the method of storing geographic locations by using relative positions along a measured linear feature. Distance measures are used to locate events along the line.