Georeference map

Use the Georeference map Cogo Adjust function to match locations in a map file to points in the job. This is useful when, for example, an architect provides coordinates for a building foundation that needs to be positioned and transferred into a real coordinate system on site. You can use the Georeference map to transform the model into the grid coordinate system used by your Trimble Access job.

If the first map files you link to the job are BIM models or DXF files in a location coordinate system that are located far from existing job data, then the software warns that the map file is far away from the job data and suggests georeferencing the file. Tap Yes to allow the software to perform an approximate georeference by relocating the center of the map file to the center of the current view. The Georeference map Cogo Adjust form opens, allowing you to fine-tune the georeferencing. If you choose not to adjust the georeferencing, tap Esc. The approximate georeference performed by the software is then removed.

The Georeference map function uses a combination of translation, rotation and scale to shift the map file so that the selected map file locations match the selected points. If you choose only one point, then the transformation uses a translation only.

Selected map file locations must be something you can select in the map, such as vertices in a BIM model or points or nodes in a DXF file.

When you open the Georeference map form, nodes are automatically shown at the ends of lines and arcs and at all points along a polyline for any DXF files shown in the map, regardless of the Create nodes setting in the Map settings screen. If the Create nodes check box in the Map settings screen is not selected, the nodes are automatically hidden when you close the Georeference map form.

  1. To open the Georeference map form, tap and select Cogo / Adjust / Georeference map.

  2. In the Map file group, select the locations in the map file you want to match to points in the job.
    1. Tap in the Point A field and then tap the point in the map.
    2. If there are several points close together, the Please select list appears. Select the point to use and then tap Accept.
    3. Repeat for Point B.

  3. In the Points group, select the points in the job to match with the map file locations. The points can be in the job or in a linked files, such as a CSV. Select first Point A and then Point B by tapping the point on the map, entering the point name, or tap next to the field and then select one of the options to select the point.

    Arrows on the map indicate the translation that will be applied to match the map file locations with the selected job points.

  4. To select whether transformations are applied and how elevations are translated:
    1. Tap Options.
    2. Select the Fix horizontal scale to 1.0 check box to not allow any horizontal scaling.
    3. Select the Fix horizontal rotation to 0 check box to not allow any horizontal rotation.
    4. In the Translate elevations field, select how to translate the map vertically. You can translate the map vertically to the elevation of point A, or to point B, or to the average of points A and B. Alternatively, you can choose to perform a 2D translation only, leaving the map at the original elevation.
    5. Tap Accept.

  5. Tap Calc.

    The map updates to show the map locations matched to the points in the job, and the Georeference map form shows the details of the rotation, scale and translation applied.

  6. If the changes do not look correct, tap Back to undo the changes. To save the changes to the job, tap Store.

    When you tap Store, a note is added to the job and a world file containing 3D data about the transformation is created. The world file has the same name as the map file with a "w" appended to the file type extension (for example, filename.ifcw or filename.dxfw) and is stored in the same folder as the map file.

    To use the map file in another project or on another controller, copy the world file along with the original map file to retain the georeferencing.