Using stationing to locate measures
Stationing is the fundamental system of measurement used for pipeline layout and construction. Stations are reference points that are placed along the horizontal measurement of a route centerline or a baseline at some regular interval. Generally, the distance between two adjoining stations along a route is 100 feet. The first station located at the beginning of the baseline is 0+00, and the next station located 100 feet from it is 1+00. Therefore, a station number of 10+34.05 denotes 1,034.05 feet (10*100 + 34.05) from the starting station.
The station numbers increase from west to east or south to north based on the cardinal direction of the overall pipeline. For pipeline projects, a starting reference station is first established; then all distances along the route centerline are measured from that point location. You can add event data to routes by entering station numbers in the Line Events tool interface. The station data is translated to routes and measures for storage.
You can use the stationing data as an input for adding linear events in the following three scenarios:
- Create a starting or base station on the route and enter the station values as an offset from that station.
- Identify a starting or base station on the route and enter the station values as an offset from that location.
- Use the preexisting stations on the route to calculate or enter the measures in the form of station values.
Using an existing station on the route as the starting station and then offset
You can use this method when you want to enter the measures using an offset distance from a selected station on the route. This functionality is available only for an LRS Network that contains a Stationing event layer.
In the following example, a starting station (yellow dot) is temporarily located with a station value. The event's start or end location is then identified by using an offset distance (in station values) from the starting or base station. When new linear events are created using this method, the stationing data is translated to routes and measures for storage.
- Open Event Editor and, if prompted, sign in to Portal for ArcGIS or ArcGIS Online.
- Click the Edit tab.
- In the Edit Events group, click the Line Events button .
- Click the Network drop-down arrow and choose the network that will serve as a source LRM for defining the input measures for the new events.
The Network is an LRS Network published as a layer in the Event Editor.
You can specify the LRS Network to be used as the LRM for defining the measure of the new point event. The widget accepts an LRS Network as a source to identify the location for adding the new point event. However, when the new point event data is being stored in the database, the application performs an internal translation of measures to always store the measure value in the linear referencing method of the LRS Network with which the event is registered.
- Choose the name of the line feature on which the events will be located using one of the following options:
- Click the drop-down arrow to choose the line name in the Line Name text box.
- Click the Select a Line on the Map tool and select the line from the map.
If the selected line is not in the active view of the map, click the Zoom to the line extent or center on the line start or end point on the Map button to refresh the map display to zoom in to the entire extent of the selected line.
The line is highlighted in light blue. The arrow at the end shows the direction of calibration of the line.
- In the From section, click the Method drop-down arrow and click Starting station and offset.
The Starting Station section appears.
- In the Starting Station section, for Station, click the Select a Location on the Map tool and choose one of the existing stations as the starting station on a route on the map.
- A yellow dot shows the location of the starting station on the route on the map.
- The Station, Units, and Direction values for the selected station are automatically populated.
- The LRM measure equivalent of the selected location is displayed in the Location field. For example, if the LRM is milepoint, the number of miles at that location will be displayed.
- The Route Name text box in the From section is automatically populated.
- In the From section, define the Station number using any one of these options to allot the From measure value for the event:
- Click the Select a Location on the Map tool and click a location on the selected route. The station number is derived from the route.
- Type the station number.
The start measure location will be placed at an offset from the starting station.
A green plus appears at the selected location on the map.
- In this example, the same starting station is used to derive the To Measure value.
A red x appears at the selected location on the map.
- Choose the date that will define the start date of the events by doing one of the following:
- Type the start date in the Start Date text box.
- Click the Start Date drop-down arrow and choose the start date.
The start date defaults to today's date, but you can choose a different date using the date picker. The end date is optional, and if it is not provided, the event remains valid now and into the future.
- Choose the date that will define the end date of the events by doing one of the following:
- Type the end date in the End Date text box.
- Click the End Date drop-down arrow and choose the end date.
- Choose from the following data validation options to prevent erroneous input while characterizing a route with linear events:
- Retire overlaps—The system will adjust the measure and start and end dates of existing events in such a way that the new event does not cause an overlap with respect to time and measure values.
- Merge coincident events—When all attribute values for a new event are exactly the same as an existing event, and if the new event is adjacent to or overlapping the existing event in terms of measure values, the new event is merged into the existing event and the measure range is expanded accordingly.
- Prevent measures not on route—This data validation option ensures that the input measure values for from measure and to measure values fall within the minimum and maximum range of measure values on the selected route.
- Click Next.
The tab showing the attribute set for the events appears.
Note:You can use the check boxes to add data for specific events within the attribute set. No records are added for unchecked events.
- Provide the attribute information for the new event in the tables defined by attribute sets.
You can use the Copy Attribute Values tool to copy event attributes from another route. Click the tool and click a route on the map to copy the event attributes.
Event Editor (EE) uses a default attribute set, as seen on the Edit tab. You can modify the attribute set to create custom attribute sets or use the administrator-configured attribute set.
- Use the following options to access more information on the attribute set:
- Check the Show network name check box to show the LRS Network associated with the selected event layer.
- The list of attributes in the tables defined by attribute sets can be from more than one event layer. If you want to identify the source event layer for each attribute, check the Show layer names check box.
- Checking the Go to the next measure upon save check box results in prepopulating the From measure value using the To measure value of the present section to continue the event creation process.
- Click Save.
The new linear events are created and appear on the map. A confirmation message appears at the lower right once the newly added line events are saved.
After a linear event has been successfully created, you have the following two options to continue characterizing the route:
- Click New Edit to clear all the input entries in the widget and restore the default values from the geodatabase to the table.
- Click Next Edit to retain all the existing entries in the widget and the attribute set for convenience and for quick editing of similar characteristics.