Creating and updating calibration points

To create and maintain measures on your LRS Network, events, and intersections, calibration points are necessary. Each route in the LRS Network has at least two calibration points that provide measure values for the route. The Update Calibration Points geoprocessing tool will create calibration points on your LRS Network and regenerate the shape of the network to provide measures. The steps to create or update calibration points, once you have created your LRS Network and loaded routes, are discussed below.

Calibrating a network using the geometric length of the source routes

Use the following steps if you plan to use the geometric length of the source routes to calibrate the network.

Steps:

1. To create or update calibration points from ArcMap, open the ArcToolbox window, expand the Roads and Highways toolbox, and double-click the Update Calibration Points tool.
   • If you clicked Yes on the Do you wish to launch Update Calibration Points tool? dialog box after loading routes, the Update Calibration Points dialog box appears.
   • If you clicked Yes after completing the route loading process, the dialog box will be prepopulated.
   • If you opened the tool from ArcToolbox, you will need to populate the parameters manually.

   The Update Calibration Points dialog box appears.
2. Select the source polyline route feature class used during route loading from the Input Polyline Features list.
3. Select the RouteID field used during route loading from the Route Identifier Field list.
4. Select the calibration point feature class from the geodatabase with your ALRS from the Calibration Point Features list.
5. Select your ALRS from the geodatabase from the Linear Referencing System (LRS) list.
6. Select your LRS Network from the ALRS from the Network list.
7. Select GEOMETRY_LENGTH_2D, or GEOMETRY_LENGTH_3D if your source polyline route feature class has z-values, from the Calculation Method list.
   Note:

   If you want to use the m-values from your source data, follow the steps in the Calibrating a network using the m-values stored in the source routes section below.
8. Select UPDATE_ALL_EXISTING_CALIBRATION_POINTS from the Update Method list.
9. Leave the Search Tolerance parameter with the default value.
10. Leave the Measure Tolerance parameter with the default value.
11. Select the Calibration Direction method to guide the direction of calibration for the routes in the network.
    • DIGITIZED_DIRECTION uses the direction of digitization of the Input Polyline Features selected to determine what direction calibration should follow.
    • MEASURE_DIRECTION uses the measure values of the Input Polyline Features selected to determine what direction calibration should follow and in which order multipart features should be calibrated.
      Note:

      This method is designed for Input Polyline Features with m-values. If your Input Polyline Features do not have m-values, the results of this method will be the same as DIGITIZED_DIRECTION.

12. Select the Gap Calibration Type method you want to use when calibrating physically gapped routes. For more information on the different methods, see Methods for calibrating routes with physical gaps.
    • STEPPING_INCREMENT will add a step to any routes with physical gaps.
    • ADDING_INCREMENT will add the increment to any routes with physical gaps.
    • ADDING_EUCLIDEAN_DISTANCE will add Euclidean distance to any routes with physical gaps.
13. Select the Increment Value to be applied for calibration of physical gaps in routes.
    Note:

    This parameter is only available if STEPPING_INCREMENT or ADDING_INCREMENT is selected.
14. Click OK.
15. When the tool is finished, click Close to return to ArcMap.

    You now have a calibrated LRS Network for use in your ALRS.

Calibrating a network using the m-values stored in the source routes

Use the following steps if you plan to use the m-value of the source routes to calibrate the network.

Note:

The feature class selected as the Input Polyline Features must be m-enabled with m-values to get the correct calibration using this method. If the feature class selected does not have m-values, you should use Geometry Length as the Calculation Method and follow the steps in the section above.

Steps:

1. Follow step 1 in the Calibrating networks using the geometric length of the source routes section above.
2. Select the source polyline route feature class used during initial route loading from the Input Polyline Features list.
3. Select the RouteID field used during initial route loading from the Route Identifier Field list.
4. Select the calibration point feature class from the geodatabase with your ALRS for the Calibration Point Features parameter.
5. Select your ALRS from the geodatabase for the Linear Referencing System (LRS) parameter.
6. Select your LRS Network for the ALRS as the Network parameter.
7. Select M_ON_ROUTE_2D, or M_ON_ROUTE_3D if your source polyline route feature class has z-values, from the Calculation Method list.
8. Select UPDATE_ALL_EXISTING_CALIBRATION_POINTS from the Update Method list.
9. Leave the Search Tolerance parameter with the default value.
10. Leave the Measure Tolerance parameter with the default value.
11. Select the unit of measure of the m-values in your source polyline route feature class as the Source Unit of Measure.

    If you chose a different unit of measure for your LRS Network, the measures for the calibration points will automatically be converted to the LRS Network unit of measure.

12. Click OK.
13. When the tool is finished, click Close to return to ArcMap.

    You now have a calibrated LRS Network for use in your ALRS.

Note:

If the resulting calibration points have NaN measures, the Input Polyline Features did not have m-values. The calibration points can be updated with the correct measures by running the Update Calibration Points geoprocessing tool with GEOMETRY_LENGTH_2D or GEOMETRY_LENGTH_3D as the method and small values (less than 0.00001) for Search Tolerance and Measure Tolerance.