Creating a new ALRS

The advanced linear referencing system (ALRS) extends the geodatabase to provide additional capabilities for linear referencing, including support for multiple linear referencing methods (LRMs), event location management, and a time-aware linear referencing system (LRS). This topic discusses the steps required to create a new ALRS in your geodatabase.

Etapes :

1. Right-click the target geodatabase and click New > Advanced Linear Referencing System.
   • In ArcCatalog, the geodatabase can be found in the Catalog tree.
   • In ArcMap, the geodatabase can be found in the Catalog window.

   The Advanced Linear Reference System Setup wizard appears.
2. Click Next.
3. Name the new ALRS and provide a brief description.
If none of the ALRS minimum schema items are present in the target geodatabase, the Create required tables and feature classes check box will be checked and those minimum schema items will be created along with the ALRS. If any of the minimum schema items are present, the check box will be unchecked.

Remarque :

• The number of steps in the wizard will be different depending on whether the Create required tables and feature classes check box is checked or unchecked. If the check box is unchecked, there will be five steps in the wizard. If the check box is checked, there will be six steps.
• If any of the required tables or feature classes are not present in your target geodatabase, the Create required tables and feature classes check box should be checked.

4. Click Next.

   The Step 2 of 6, Minimal schema dialog box appears.

5. Select the XY and Z tolerance for the centerline, calibration point, and redline feature classes. You can either enter the values by typing in the text boxes forXY Tolerance and Z Tolerance or by selecting the tolerance values from an existing feature class, such as your source routes, by clicking the browse button to the right of the text boxes.

   • The tolerance settings selected during this step will be used for the LRS Network feature class for each network created. These tolerance settings will also determine the level of precision and number of decimal places displayed for measures on your network.
   • If you are not creating the minimum schema items during ALRS creation, you should ensure the spatial reference and tolerance settings for your centerline, calibration point, and redline feature classes all match since they will be applied to any LRS Networks you create.

   Remarque :

   It is recommended that the tolerance settings of your ALRS match those of your source route feature class. This will ensure the shape and length of your routes are the same in your LRS Networks as in your source route feature class.

6. Select the spatial reference of your required tables and feature classes by clicking the browse button next to the Spatial Reference field. If you selected an existing feature class for your XY and Z tolerance in the previous step, the spatial reference of that feature class is automatically selected for you.

   The spatial reference of your ALRS should match the spatial reference of your source polyline route feature class.

7. Click Next.

   The Step 3 of 6, Schema dialog box appears.

   Remarque :

   If you checked the Create required tables and feature classes check box, you can use the default values for steps 3 through 5 in the ALRS Setup wizard.

8. Map the ALRS schema to the proper data elements.

   See ALRS data model to learn about the data elements used in the ALRS.

9. Click Next.

   The Step 4 of 6, Route relationships dialog box appears.

10. Define the route relationships to be used in the ALRS schema.
    1. To change the fields serving as the link between the Centerline feature class and Centerline Sequence table, Centerline Sequence table and Route table, or Calibration Point feature class and Route table, double-click the black connector lines on the Route relationships page of the Advanced Linear Reference System Setup dialog box (step 3 of 5 or 4 of 6) to display the Edit Relationship dialog box.
    2. Use the field drop-down arrows to set the primary and foreign keys for the relationships between routes, centerlines, and calibration points. The fields you select will link the geometry of the centerline feature class to the routes in the route table via the centerline sequence table to ensure the LRS Network has geometry and routes. Additionally, it will ensure the calibration points are correctly linked with the route table and the LRS Network once they are created.

       See ALRS data model to learn about the relationships in the ALRS.

    3. Click OK.
11. Click Next.

    The Step 5 of 6, Field Mapping dialog box appears.

12. Map fields to ALRS data elements.
    1. Choose ALRS data elements using the Table/Layer drop-down arrow.
    2. Map the ALRS fields to the data element field names using the Mapped To drop-down arrow.

       See ALRS data model to learn more about the ALRS data elements.

13. Click Next.
14. Click Finish to finish creating the ALRS and close the wizard.

    The Question message appears asking if you want to create a new network.

15. Choose one of the options and close the ALRS setup wizard.
    • Click Yes to create a new network.
    • Click No to close the ALRS setup wizard and return to ArcMap. If the networks in your ALRS will use a concatenated routeID or will contain coded value domains/subtypes, you should choose this option and follow the steps in Using concatenated route identifiers.