The GeoRegister tool allows you to create a relationship between a real-world coordinate system and an area on a 2D or 3D PDF page.

For instructions on how to access the GeoRegister tool, see Accessing the GeoPDF Composer Toolbar.

In this document:

GeoRegister capabilities

In addition to creating the GeoRegistration, the GeoRegister tool allows you to define a user coordinate system that is distinct from that used for the GeoRegistration, draw a neatline around the GeoRegistered area on the 2D PDF page, and to assign a name to the map frame which results from the GeoRegistration process.

When you GeoRegister a PDF file or modify a GeoPDF file it is automatically enabled for comments and measuring/analysis in Adobe Reader. Reader Enabled GeoPDF files provide your users access to the GeoPDF GeoMark Toolbar, through which they can add points, polylines and polygons to a map. Users can also import, export and delete GeoMarks as well as create filters for viewing GeoMarks and manage peer-to-peer imports, exports and GeoForms.

You can also specify the version of GeoPDF Toolbar with which the GeoPDF file should be compatible. The default compatibility value is the GeoRegistration encoding method you specified in the GeoRegistration Format Compatible With list box on the TerraGo Preferences dialog box. If you did not specify an encoding method, the default for the GeoRegistration Format Compatible With list box is TerraGo GeoPDF Toolbar 3+ (OGC).

GeoRegistering a 3D PDF page is also described below, however, before you can GeoRegister 3D data you must convert the data to a 3D PDF using Acrobat's 3D tools. Refer to the Acrobat online Help for more information. GeoPDF Composer must be properly licensed to GeoRegister a 3D PDF page.

GeoRegistration requirements

To perform a GeoRegistration, you must be able to:

• Recognize or be able to define the appropriate spatial reference system for the area on a PDF page

• Recognize or be able to define a datum shift for taking geodetic coordinates from that of the spatial reference system into WGS84

• Identify with accuracy and precision suitable to your application two or more registration points and be able to express their location in either the projected or geodetic coordinates of the underlying spatial reference system

• To GeoRegister a 3D PDF, you must be able to create an .xml file that contains the registration points for your 3D PDF page

Starting the GeoRegistration

• From the GeoPDF Composer Toolbar, click the GeoRegister tool. If the Continue? message box appears, click Yes to GeoRegister your PDF file.

• Type a description of the map frame in the Description box.

Selecting the TerraGo GeoPDF Toolbar Compatability

The Make Compatible With option allows you to choose whether your GeoRegistered PDF should be compatible with TerraGo GeoPDF Toolbar 3+ (OGC), GeoPDF Toolbar 5+ (OGC Preferred), or GeoPDF Toolbar 5+ (ISO Only).

GeoPDF Toolbar 3+ (OGC)

When you choose GeoPDF Toolbar 3+ (OGC), GeoPDF Composer uses the TerraGo GeoRegistration encoding method that was published as an OGC best practice in 2008 to GeoRegister the PDF file. The OGC best practice is the most widely distributed GeoRegistration encoding in terms of existing PDF libraries and workflows because GeoPDF was the only geospatial PDF available preceding the release of Acrobat 9.

GeoPDF Toolbar 5+ (OGC Preferred)

When you choose GeoPDF Toolbar 5+ (OGC Preferred), GeoPDF Composer prefers to use TerraGo's GeoRegistration encoding method that was published as an OGC best practice in 2008 to GeoRegister the PDF file. The OGC best practice is the most widely distributed GeoRegistration encoding in terms of existing PDF libraries and workflows because GeoPDF was the only geospatial PDF available preceding the release of Acrobat 9. If the selected coordinate system is not supported in OGC, GeoPDF Composer encodes the GeoRegistration using ISO 32000.

Adobe implemented a different PDF GeoRegistration encoding when it released Acrobat 9 and submitted that method to ISO as a proposed extension to ISO 32000. Both OGC and ISO GeoRegistration methods encode the same information; however, more coordinate systems are supported using Adobe's GeoRegistration encoding. TerraGo software is capable of reading and writing both encoding methods.

GeoPDF Toolbar 5+ (ISO Only)

When you choose GeoPDF Toolbar 5+ (ISO Only), GeoPDF Composer uses only the ISO 32000 method to GeoRegister the PDF file.

Defining map coordinates

GeoPDF Toolbar 3+

• Click Map Coordinates.

• From the Projection list box, select the appropriate projection type for your coordinate reference system. Not all of the coordinate reference system types are formally projections, but have been added as a convenience. Selecting a particular projection type will result in zero or more fields for selecting parameters appropriate to that projection type. Angular values should be entered as degrees.

• If appropriate, from the Datum list box, select the datum to which the coordinate system is referenced. Be aware that when you select a datum you are also selecting a shift that takes longitudes and latitudes referenced to that datum to WGS84.

• If appropriate, from the Units list box, select the units.

• Complete any remaining fields as needed and then click OK.

GeoPDF Toolbar 5+

Click Map Coordinates. There are four ways to define a coordinate reference system in the Coordinate System Selector window.

Predefined

• To select from a predefined list of coordinate systems, type the first few characters of the coordinate system name in the Smart Search box in the Predefined tab. You can filter your search to reduce the number of found records by selecting specific coordinate system and projection types.

• From the Coordinate System Type list box, choose either Geographic or Projected.

• From the Projection Types list box, choose Gauss Kruger, Polar, State Plane, UTM, or WGS 84 SCAR.

• Select the coordinate system in the left pane to view the details in the right pane.

Modifying pre-defined coordinates:

• To modify the details of the selected coordinate system, click Edit.

• In the Custom tab, make any modifications to create a custom coordinate system.

Saving your coordinate system:

• To save the selected coordinate system in a .wkt file, click Save to file.

• Type the .wkt file name in the File name box.

• Click Save and then OK.

Custom

Note: Applying a custom coordinate system to a GeoPDF or geospatially-aware PDF file may produce an inaccurate or invalid GeoRegistration.

To ensure success when creating a custom coordinate system, refer to the information presented by the OGP Surveying and Positioning Committee at the EPSG (European Petroleum Survey Group). To understand the parameters required to identify coordinates such that those coordinates describe a position unambiguously as well as define transformations and conversions that allow coordinates to be changed from one CRS to another CRS, refer to the documentation on the EPSG Geodetic Parameter Dataset page. To review all of the geodetic awareness guidance notes, refer to Guidance Notes.

Defining a custom projected coordinate system:

• Click the Custom tab.

• From the Projection list box, click the projection on which your source image file should be based.

• Complete the projection details as needed.

• From the Parameter Units list box, click the unit of measurement the selected projection should be based on.

• In the Datum Smart Search text box, type the first few characters in the datum name and select the appropriate datum.

• From the WGS 84 Transformations list box, click the transformation shift to apply to your custom coordinate system or specify whether the shift is not a transformation but an ellipsoid shift.

• Modify the transformation details as needed.

• To save the custom coordinate system in a .wkt file, click Save to file. Type the .wkt file name in the File name box.

• Click Save and then OK.

Note: If the text on the right panel turns red, you must select a datum and a shift to WGS84.

Defining a custom geographic coordinate system:

• Type a few characters in the Datum Smart Search box.

• Modify the transformation details as needed.

• To save the custom coordinate system in a .wkt file, click Save to file.

• In the Save file dialog box, in the File name text box, type the name of this .wkt file and then click Save. Click OK.

Note: The string in the .wkt file must not exceed 16000 characters.

Import

• To import a coordinate system via a .prj or .wkt file, click the Import tab.

• Type the path and file name to the .prj or .wkt file, or click Browse to open the Select file dialog box through which you can navigate to the location of the file.

• Click OK.

History

To apply one of the fifteen recently used coordinate systems, click the History tab. From the left pane, select the coordinate system to apply. Click OK.

Adding registration points

Notes:

GeoRegistration requires a minimum of two points to convert your file to a GeoPDF file. These points may not lie along the coordinate axes of either the PDF page or projected coordinate reference system. You can verify that this is or is not the case by examining the values displayed in the Registration Points dialog box.

Using two points, the registration is calculated assuming that the scale is constant in all directions. Using three points, scales for each coordinate axis are calculated. If four or more points are used, a linear least squares optimization determines a best-fit registration. In this case, fit deviation values are displayed.

We recommend that you insert all registration points at the same zoom level.

If you change tools, you can recover the Point Selection Tool dialog box by clicking Select Point.

Manually registering points

• Click Registration Points and then click Add to access the Select a point dialog box.

• In the Select a point dialog box, click the radio button on which the point's coordinates are to be entered. The text box labels dynamically change based on your selection.

• Click the map where you want to register a point. The point displays as a large X.

• Enter either a Longitude/Latitude or Easting/Northing pair, as appropriate, for the selected point.

  • If you click the Easting /Northing radio button, type the Eastward measured distance (or the x-coordinate) of the point in the E: (m) text box, then type the Northward measured distance (or the y-coordinate) of the point in the N: (m) text box.

  • If you click the Longitude /Latitude radio button, type the angular measurement ranging from 0° at the prime meridian to +180° eastward and −180° westward in the Lon text box, then type the angular measurement ranging from 0° at the equator to 90° N at the North Pole or 90° S at the South Pole in the Lat text box.

  • If you do not want to register the selected point, click the map to register a different point.

• Click OK. Your first point coordinates display in the Registration Points grid.

• Click Add to return to the Select a point dialog box.

Importing registration points

• Click Registration Points and then click Import Points.

• In the Select file dialog box, navigate to the folder in which the .xml file associated with your 2D PDF page resides, then click Open. The registration points in the file display in a grid.

• Your .xml file must be properly formatted in order to import registration points. For more on GeoRegistration .xml formatting, see GeoRegistration XML.

• A properly formatted 2D GeoRegistration file has the following layout:

<georeg version='1.0'>
  <points>
    <point>
      <projected east='558064' north='5121800'/>
      <model x='558064' y='5121800'/>
    </point>
  </points>
</georeg>

• After you have added the necessary points to your file, click OK.

GeoRegistration options

A properly defined map coordinate reference system and two or more valid registration points enables the OK button on the GeoRegistration dialog box. All further steps are optional.

User coordinates

User Coordinates are the units with which the user interacts with the map

• Click User Coordinates.

• Follow the same procedure as the Map Coordinates process.

• Complete any remaining fields as needed and then click OK

To set the user coordinates to the same coordinates as those on which the map frame was based, select Same as Map in the GeoRegistration dialog box.

Neatline

A neatline is a boundary on the PDF page that defines the limits of validity for the GeoRegistration. By default, the neatline is the page boundaries. In some cases it is desirable to manually assign a neatline, such as in ascribing boundaries to an inset map.

• Click Neatline.

• A single-click makes a vertex for the bounding box. A double-click completes the sketch. A right-click backs-up the sketch to the previous vertex.

• If you zoomed while drawing the neatline, click the dialog box to resume setting points.

• Click Clear Neatline to redraw your bounding box.

  A neatline is not required, but defining a neatline limits the display of coordinate points to inside the neatline rather than anywhere on the page. A neatline is required if you are creating a GeoPDF template file to be used by the Batch GeoRegistration tool.

  If you are creating a GeoPDF template file to be used by the Batch GeoRegistration, the points of the neatline must match the coordinates of your map source in anti-clockwise from the lower left vertex order.

Completing the GeoRegistration process

• Click OK to complete the GeoRegistration process for the file.

• If you need to add, modify or delete a map frame, click the appropriate button and then follow these steps starting at step 2; otherwise, click Close.

• From File on the main menu, click Save As.

• In the File name list box, type the name of the GeoPDF file.

• Click Save.

You should test the accuracy of your GeoPDF file before distributing it to your users. Use the GeoLocator tool on the GeoPDF Toolbar to enter known coordinates and measure the difference between the marker and the actual point.

GeoRegistering a 3D PDF page

Before you can GeoRegister 3D data you must convert the data to a 3D PDF using Acrobat's 3D tools. Refer to the Acrobat online Help for more information.

GeoPDF Composer must be properly licensed to GeoRegister a 3D PDF page. If GeoPDF Composer is not properly licensed, the 3D check box on the GeoRegistration dialog box is disabled to prevent you from adding a new map frame. If you attempt to modify an existing map frame, a message box appears indicating that you cannot change the GeoRegistration, and the OK button on the GeoRegistration dialog box is disabled. If you try to delete an existing map frame, a message box appears indicating that you cannot remove a 3D map frame.

Starting the GeoRegistration

• Activate the Adobe Acrobat 3D toolbar.

• From the GeoPDF Composer Toolbar, click the GeoRegister tool . If the Continue? message box appears, click Yes to GeoRegister your PDF file.

• Type a description of the map frame in the Description box.

• Check the 3D box.

When GeoRegistering a 3D PDF, the Make Compatible With list box will be disabled The default GeoPDF Toolbar version defaults to the option selected in the GeoRegistration Format Compatible With list box in the TerraGo Preferences dialog box.

Defining map coordinates

Click Map Coordinates. There are four ways to define a coordinate reference system in the Coordinate System Selector window.

Predefined

• To select from a predefined list of coordinate systems, type the first few characters of the coordinate system name in the Smart Search box in the Predefined tab. You can filter your search to reduce the number of found records by selecting specific coordinate system and projection types.

• From the Coordinate System Type list box, choose either Geographic or Projected.

• From the Projection Types list box, choose Gauss Kruger, Polar, State Plane, UTM, or WGS 84 SCAR.

• Select the coordinate system in the left pane to view the details in the right pane.

Modifying pre-defined coordinates:

• To modify the details of the selected coordinate system, click Edit.

• In the Custom tab, make any modifications to create a custom coordinate system.

Saving your coordinate system:

• To save the selected coordinate system in a .wkt file, click Save to file.

• Type the .wkt file name in the File name box.

• Click Save and then OK.

Custom

Note: Applying a custom coordinate system to a GeoPDF or geospatially-aware PDF file may produce an inaccurate or invalid GeoRegistration.

To ensure success when creating a custom coordinate system, refer to the information presented by the OGP Surveying and Positioning Committee at the EPSG (European Petroleum Survey Group). To understand the parameters required to identify coordinates such that those coordinates describe a position unambiguously as well as define transformations and conversions that allow coordinates to be changed from one CRS to another CRS, refer to the documentation on the EPSG Geodetic Parameter Dataset page. To review all of the geodetic awareness guidance notes, refer to Guidance Notes.

Defining a custom projected coordinate system:

• Click the Custom tab.

• From the Projection list box, click the projection on which your source image file should be based.

• Complete the projection details as needed.

• From the Parameter Units list box, click the unit of measurement the selected projection should be based on.

• In the Datum Smart Search text box, type the first few characters in the datum name and select the appropriate datum.

• From the WGS 84 Transformations list box, click the transformation shift to apply to your custom coordinate system or specify whether the shift is not a transformation but an ellipsoid shift.

• Modify the transformation details as needed.

• To save the custom coordinate system in a .wkt file, click Save to file. Type the .wkt file name in the File name box.

• Click Save and then OK.

Note: If the text on the right panel turns red, you must select a datum and a shift to WGS84.

Defining a custom geographic coordinate system:

• Type a few characters in the Datum Smart Search box.

• Modify the transformation details as needed.

• To save the custom coordinate system in a .wkt file, click Save to file.

• In the Save file dialog box, in the File name text box, type the name of this .wkt file and then click Save. Click OK.

Note: The string in the .wkt file must not exceed 16000 characters.

Import

• To import a coordinate system via a .prj or .wkt file, click the Import tab.

• Type the path and file name to the .prj or .wkt file, or click Browse to open the Select file dialog box through which you can navigate to the location of the file.

• Click OK.

History

To apply one of the fifteen recently used coordinate systems, click the History tab. From the left pane, select the coordinate system to apply. Click OK.

Importing registration points

• Click Registration Points and then click Import Points.

• In the Select file dialog box, navigate to the folder in which the .xml file associated with your 3D PDF page resides, then click Open. The registration points in the file display in a grid.

• Your .xml file must be properly formatted in order to import registration points. For more on GeoRegistration .xml formatting, see GeoRegistration XML.

• A properly formatted 3D Geographic Coordinate System GeoRegistration file has the following layout:

<georeg version='1.0'>
  <axes>
    <geographic lat='-x' elev='y' elev-unit='m' />
    <scale y='89863.64 />
  </axes>
  <points>
    <point>
      <geographic lon='-112.75' lat='36.5158' elev='22.7' />
      <model x='-112.75' y='36.5158' z='0' />
    </point>
  </points>
</georeg>

• A properly formatted 3D Projected Coordinate System GeoRegistration file has the following layout:

<georeg version='1.0'>
  <axes>
    <geographic lat='-x' elev='y' elev-unit='m' />
    <scale y='89863.64 />
  </axes>
  <points>
    <point>
      <projected east='558064' north='5121800' elev='22.7' />
      <model x='558064' y='5121800' z='0'/>
    </point>
  </points>
</georeg>

• A properly formatted 3D Cartesian Coordinate System GeoRegistration file has the following layout:

<georeg version='1.0'>
  <axes>
    <cartesian x='x' y='-z' z='y' />
  </axes>
  <points>
    <point>
      <cartesian x='558064' y='5121800' z='0 />
      <model x='558064' y='5121800' z='0' />
    </point>
  </points>
</georeg>

• Click OK to return to the GeoRegistration dialog box.

User Coordinates (optional)

User Coordinates are the units with which the user interacts with the map.

Follow the same procedure as the Map Coordinates process.

Complete any remaining fields as needed and then click OK.

To set the user coordinates to the same coordinates as those on which the map frame was based, insert a check mark in the Same as Map check box in the GeoRegistration dialog box.

Defining the model

• Click Model.

• Click the 3D model that you are GeoRegistering, then click OK.

• Click Clear Selection to re-select your 3D model.

Completing the GeoRegistration process

• Click OK to complete the GeoRegistration process for the file.

• If you need to add, modify or delete a map frame, click the appropriate button and then follow these steps starting at step 2; otherwise, click Close.

• From File on the main menu, click Save As.

• In the File name list box, type the name of the GeoPDF file.

• Click Save.

You should test the accuracy of your GeoPDF file before distributing it to your users. Use the GeoLocator tool on the GeoPDF Toolbar to enter known coordinates and measure the difference between the marker and the actual point.