Instructions provided describe how to create a route with measured values that reflect the 3D length of a line.
The Create Routes tool in the linear referencing toolset of ArcToolbox applies measured values to linear features that share the same route ID. By selecting the 'Length' option under 'Measure Source', the 2D length of the line is used to determine the measure of that segment.
Even if the line is z-aware, it does not consider these elevations values when calculating the length. In order to create routes with measured values that reflect the 3D length of the line, the surface length of the line must be calculated.
A TIN, or elevation raster dataset, and the 3D Analyst extension is required for this procedure.
- Run the Split Line At Vertices tool on the route feature class to create 2-point line features.
a) Open the Split Line At Vertices tool from ArcToolbox > Data Management Tools > Features.
b) Input the route feature class into input features.
c) Select an output location and name for the output line feature class.
d) Click OK to run.
- Run the Surface Length tool on the output feature class of the last step to calculate the 3D length of each segment.
a) Open the Surface Length tool from ArcToolbox > 3D Analyst > Functional Surface.
b) Select the elevation raster dataset or TIN for the Input Surface.
c) Select the 2 point line feature created in the last step for the Input Feature Class.
d) Specify the Surface Length Field. This field contains the 3D length of each feature.
d) Click OK to run.
- Run the Create Routes tool on the output feature class and specify the measure source as the field containing the 3D lengths.
a) Open the Create Routes tool from ArcToolbox > Linear Referencing Tools.
b) Specify the line feature created in the previous steps as the Input Features.
c) Enter the field that uniquely identifies the routes for the Route Identifier Field.
d) Browse and save the Output Route Feature Class.
e) Change the Measure Source to One_Field.
f) Select the field containing the 3D lengths in the From-Measure Field dropdown.
e) Click OK to run.