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  4. Assigning a Coordinate Reference System
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  4. Assigning a Coordinate Reference System
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  4. Assigning a Coordinate Reference System
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  4. Assigning a Coordinate Reference System

Assigning a Coordinate Reference System

Within CivilGEO software, every data layer has its own coordinate reference system which is used to integrate it with other data layers within the Map View. Data layers that are constructed with different coordinate reference systems are automatically reprojected to the Map View so that they align with the assigned project coordinate reference system.

To define a coordinate reference system (CRS) for the project, follow the steps below:

  1. From File on the ribbon menu, select Map Coordinates option.
    Map Coordinates option
  2. The Map Coordinates backstage page will be displayed.
    Map Coordinates Backstage Page
  3. From the Projected CRS Regions tab, the user can browse to the supported CRS for the location of interest by expanding the continent, country, and then local region. The software will then list all the coordinate reference systems that correspond to the selected location. Note that some countries straddle the Europe, Asia, and Africa boundaries, and are grouped into the Asia, Middle East subregion. Note that countries located in the southwest Pacific Ocean region are grouped into the Australasia continent.
  4. From the Projected CRS Listing tab, the user can browse through all the supported CRS contained within the software. Once the desired CRS category is found, the user can then expand the category to see all the listed CRS that correspond to a selected category.
    Projected CRS Listings panel
  5. From the Import CRS Projection tab, the user can import custom projected coordinated reference system files supported by the software. To learn how to use this tab, refer to this article in our knowledge base.
    Import CRS Projection panel
  6. From the Favorites tab, the user can quickly access the CRSs that are frequently used without having to browse through the entire CRS directory. To add a CRS to the Favorites tab, select the required CRS. Then, right-click, and select the Add to Favorites option from the displayed context menu.
    Favorites panel
  7. Alternatively, the user can manually enter the region (i.e., state) of interest in the search field and then click on the [Search] button. The software will then filter out only those CRS that correspond to the defined region. For example, entering “Penn” (for Pennsylvania) will only return CRS that correspond to that state.
    [Search] button
  8. Single clicking on a listed CRS will show the bounds of the CRS in the Preview window.
  9. Once the CRS is selected, the user can click the [Apply to Map View] button to assign the selected CRS to the project. Alternatively, double clicking on a listed CRS will assign the selected CRS to the project.
  10. Additionally, the user can assign a CRS to the current project by simply loading a CRS projection file.
    The user can click the [Load CRS Projection] button and select a CRS projection file from the Load CRS Projection dialog box. The user can then click the [Apply to Map View] button to assign the CRS to the project.
    [Load CRS Projection] button

Note that the Hide depreciated coordinate reference systems checkbox is used to hide the old, depreciated coordinate reference system. By default, this checkbox is checked.

Automatic Assigning CRS to Non-CRS Data Layers

While assigning the coordinate reference system (CRS) to the project, the Map Coordinates backstage page provides a checkbox option (Apply CRS to all non-CRS referenced layers), which assigns the selected CRS to layers that are not yet assigned a specific CRS system.
Apply CRS to all non-CRS references layers checkbox

By default, this checkbox is checked (i.e., selected). However, some non-CRS referenced data layers may not lie within the selected project CRS. If this occurs, the software will display an informational dialog box describing this issue for each of the data layers whose coordinates lie outside the assigned CRS. The user has the option to continue with the CRS assignment for the data layer or skip over it. This commonly happens with HEC‑RAS models that were not created in a coordinate reference system. In these situations, it is better to skip over the assignment of the CRS. The data layer may need to be manually georeferenced.

Manually Assigning of CRS to a Non-CRS Data Layer

If a data layer has been added to a project and does not have a CRS defined for it, the layer will display in its own local coordinate reference system. This might happen, for example, when importing an elevation grid data file to the project.

After loading the data layer, only that data layer will be shown in the Map View. The other data layers lie in a different projection of the Map View. The user can then manually assign the project’s CRS to the data layer if the data layer coordinates lie within the project’s CRS. Refer to this article in our knowledge base to learn how to manually assign a CRS to a data layer.

About the Author Chris Maeder

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