Georeferencing Manholes

The Georeference Manholes command allows the user to manually georeference each of the manholes to the background base map displayed in the Map View.

The process of georeferencing a manhole to the Map View can be a trial and error process—especially when the exact location of the original manhole is not known. With the use of the Georeference Manholes command, the georeferencing process can be accelerated.

Note that a CRS should be assigned before running this command. Otherwise, the software will display the below informational dialog box.

Refer to this article in our knowledge base to learn how to assign a coordinate reference system to a project.

Follow the steps below to georeference an existing manhole:

1. From the Input ribbon menu, click on the Manhole Structures dropdown menu and select the Georeference Manholes command.
   
2. The Georeference Manholes dialog box will be displayed.
   

The following sections describe how to georeference an existing manhole and interact with the above dialog box.

Selecting Manhole to Georeference

The Select Manhole to Georeference section allows the user to select the manhole that is to be georeferenced.

Follow the steps below to select the manhole to be georeferenced:

1. Select the manhole from the Manhole ID dropdown combo box listing all the manholes contained within the current scenario.
   
2. Alternatively, the user can click the [Pick] button to select the manhole from the Map View. After clicking the [Pick] button, the Georeference Manholes dialog box will temporarily disappear, and a prompt will be displayed on the status bar instructing the user on what to do next.
3. Upon selecting the manhole, the user is immediately returned to the dialog box, and the selected manhole will be highlighted on the Map View.
4. The user can click the [Clear] button to cancel the previous selection and redo the entire process.

Once the manhole has been selected, the user can choose between the following options to georeference the manhole:

• Snap to Alignment Point
• Slide Along Alignment Polyline
• Draw on Map View

Snapping Manhole to an Alignment Point

If an existing alignment point for the manhole exists on the Map View, the Snap to Alignment Point option can be used to snap the manhole to the alignment point.

Follow the steps below to use the Snap to Alignment Point option:

1. Select the Snap to Alignment Point radio button option.
2. Click the [Pick] button.
   
3. The Georeference Manholes dialog box will temporarily disappear, and a prompt will be displayed on the status bar instructing the user to select the alignment point.
4. Select the alignment point on the Map View. Note that the user can select only one alignment point at a time to use for georeferencing.
5. The Georeference Manholes dialog box will be redisplayed and the status of the Select alignment point read-only field will be changed from Not Selected to Selected. The user can click the [Clear] button to cancel the previous selection and redo the entire process.
   
6. Click the [Snap] button to snap the selected manhole to the alignment point.
   
   Once the user clicks the [Snap] button, the following informational dialog box will be displayed.
   
   Click the [Yes] button to split the entity or abort the split process by clicking the [No] button.

Sliding Manhole Along Alignment Polyline

If a manhole has been snapped to an alignment point on the Map View but is not precisely located where it should be, the Slide Along Alignment Polyline option can be used to slide the manhole along the alignment polyline.

Follow the steps below to use the Slide Along Alignment Polyline option:

1. Select the Slide Along Alignment Polyline radio button option.
2. Click the [Pick] button.
   
3. The Georeference Manholes dialog box will temporarily disappear, and a prompt will be displayed on the status bar instructing the user to select the alignment polyline from the Map View.
4. After selecting the alignment polyline, the following informational dialog box will be displayed. Click the [Yes] button to select the polyline or abort the selection by clicking the [No] button.
   
5. Once the alignment polyline is selected, the Georeference Manholes dialog box will be redisplayed and the status of the Select alignment polyline element read-only field will be changed from Not Selected to Selected. Then click the [Slide] button.
   
6. The Georeference Manholes dialog box will temporarily disappear, and a prompt will be displayed on the status bar instructing the user to select the manhole and drag it along the underlying alignment polyline.
7. Click and drag the manhole on the Map View to revise its alignment.
8. When finished, press the [Enter] key or right-click and select Done from the displayed context menu. The Georeference Manholes dialog box will be redisplayed, and the manhole will be georeferenced at the new location.

Note that for more precision, the user can use the Snap to Alignment Point option first and then use the Slide Along Alignment Polyline option.

Drawing Manhole on Map View

The Draw on Map View option allows the user to draw a manhole node on the Map View and automatically snap the selected manhole to the drawn node.

Follow the steps below to use the Draw on Map View option:

1. Select the Draw on Map View radio button option and click the [Draw] button.
   
2. The Georeference Manholes dialog box will temporarily disappear, and a prompt will be displayed on the status bar instructing the user to draw the manhole node on the Map View.
3. Draw the manhole node on the Map View. When finished, press the [Enter] key or right-click and select Done from the displayed context menu.
4. The Georeference Manholes dialog box will be redisplayed, and the manhole will automatically snap to the drawn node.

Assigning Rim & Invert Elevations

The user can check the Assign Rim & Invert Elevations checkbox option to assign rim and invert elevations to the manhole using a terrain model.

Define this section before georeferencing manholes so that the rim and invert elevations can be assigned.

To assign rim and invert elevations, the Terrain elevation source dropdown combo box supports the following surface types:

• Elevation grids
• LandXML data
• TIN surfaces

Depending upon the elevation data source type that is selected, different options are provided to specify additional elevation data information.

The user can define an invert depth using the Manhole depth entry field to raise or lower the invert of the manhole by the specified amount. A negative invert depth value lowers the manhole by the specified amount.

The user can use the Sump depth entry field to define the sump depth required at the manhole. The sump depth of a manhole represents the vertical offset from the manhole bottom invert elevation to the lowest invert of the connected pipes.