Measures and Linear Reference Systems

A Linear Reference System (LRS) is used to store locations relative to their positions along a linear feature that has measures. Distance measures are then used to identify the location of these points or lines along the linear feature, rather than using X,Y values. Rather than rely on calculating the length of the (possibly simplified) geometries, then a measure (m) value is stored on each vertex of the line to store the real-world distance.

1Integrate can read and write data from the following data stores that have LRS measures stored on line geometries as a third ordinate (M).

Data Store Type M Ordinate supported as standard M Ordinate supported using FME Desktop
Read Write Read Write

Bentley Microstation Design (V8)

 A cross mark A cross mark A cross mark A cross mark

Comma Separated Value (CSV)

 A cross mark A cross mark A cross mark A cross mark

Autodesk AutoCAD DWG/DXF

 A cross mark A cross mark A cross mark A cross mark

Esri Enterprise Geodatabase

 A cross mark A cross mark A tick mark A tick mark

Esri File Geodatabase

 A tick mark A cross mark A tick mark A tick mark

Esri Shapefile

 A tick mark A tick mark A tick mark A tick mark

MapInfo Tab

 A cross mark A cross mark A cross mark A cross mark

Microsoft SQL Server Spatial

 A cross mark A cross mark A cross mark A cross mark

Oracle

 A tick mark A tick mark A cross mark A cross mark

PostGIS

 A tick mark A tick mark A cross mark A cross mark
Web Feature Surface (WFS) A cross mark A cross mark A cross mark A cross mark

Note: X, Y, Z, M is not supported, only X,Y,M or X,Y,Z values.

There are a number of specific Built-in functions that use measures. Typical use cases are:

  • Generating a point geometry or line geometry for an asset which uses Linear Referencing, this can include a start measure and optionally (for a line) an end measure along it.
  • Generate a measure distance along an LRS line from a geometry.
  • Validate measures, e.g. measure distance is not off the end of the referenced line.