Work with geolocation data

Once your project is created and you're on the home screen, you can start processing your imagery. If you need to update information about the images before processing, use the Flight Data tab.

You can view or edit the following information in the Geolocation group:

• Change the source of the images' GPS data.
• Adjust the altitudes of the images.
• Export GPS data.

Currently, Yaw, Pitch, and Roll from the drone metadata or Omega, Phi, Kappa from an external geolocation file are supported. When this data exists, you can check the Use Image Orientations check box in the project processing options by going to the Home tab and clicking Options > Adjust Images > Use Image Accuracy. This allows the processing engine to skip the orientation step and use the provided image orientation data to calculate the image orientations, speeding up processing. This orientation data is written to a different file in the project: \Project\Data\images.json.

Set the GPS source

The GPS source is set during project creation but can be updated from the Flight Data tab. Drone2Map allows you to set the GPS source for selected images in the project. To update basic image GPS source information, complete the following steps:

1. Select one or more images.
2. Click GPS Source on the Flight Data tab.
3. In the Set GPS Source window, use the drop-down menus in the GPS Information section to specify what information to modify.

   You can change GPS Altitude Reference to be above or below sea level. GPS Latitude Reference and GPS Longitude Reference can also be modified with the desired cardinal direction.

4. Click OK to update the GPS information.

Click the Reset to EXIF button to reset GPS information for images back to its original imported state when the project was created.

Import GPS information

If you have previously exported GPS information or want to completely change the existing images' information, use the Import tab to import the new GPS information for project images. To import new GPS information for images, complete the following steps:

1. Click GPS Source on the Flight Data tab.
2. In the Set GPS Source window, click the Import tab.
3. Click the Browse button to open the Browse to GPS file window.
4. Select a text file containing GPS information in either TXT, CSV, or MRK format.
5. Click OK.

   The Geolocated Images value near the top of the window changes from 0. The GPS Field Information section autopopulates with corresponding fields from the imported file.

6. Click OK to update the GPS information.

Adjust image altitudes

Drone2Map reads image altitude information from the image EXIF data or from an external file. You can view altitude information in the Images table. If you are not confident in the accuracy of the altitude values for your images, you may want to update your altitudes using the flying height you set during mission planning. To do this, Drone2Map queries a user-defined elevation source to establish the ground elevation for each image center and adds the flight height value you input to establish new altitude values. To adjust your image altitudes, complete the following steps:

1. Click Image Altitude .
2. Select the elevation source type from the Adjust using drop-down list. Select Digital Elevation Model if you have a local DEM dataset, Constant Elevation, or leave the default Elevation Service.
3. If your drone collects height above ground metadata, the Use Metadata check box is checked and data from your drone will be used.
4. If the Use Metadata check box is unavailable, input the flight altitude as height above ground and the units.

   If your flight was collected at multiple orbits or passes at different altitudes and does not have relative altitude metadata, when entering a value in the Flight Altitude parameter, use the flight altitude of the first image of the flight.

5. If you selected Constant Elevation, enter the takeoff elevation and units.
6. If you selected Elevation Service, leave the default service or uncheck the check box and enter your own elevation service. If you selected Digital Elevation Model, browse to your local elevation file (.tif, .jpg, .jpeg, .jpe, .jfif, or .png) and open it.
7. Click OK.

   A message appears indicating that your altitudes will be set to the elevation retrieved from the elevation source plus your input height. Click OK to proceed.

Note:

By default, image altitude is adjusted using the values from the topmost elevation surface in the Elevation Surfaces section of the Contents pane. If there is an offset between output products and the elevation surface, it is likely that the WorldElevation3D/Terrain3D layer was used for adjustment. For more accurate adjustments, use a local DEM and ensure it is the top layer in the Elevation Surfaces section when running the adjustment.

Export GPS

To export all image information in TXT, CSV, or MRK format, complete the following steps:

1. Select images.
2. Click Export GPS.
3. Choose a location in your local file system to save the file.
4. Click Save.

Note:

If you experience issues with the GPS data stored in image EXIF data, you can use the Export tool to save the image information to a file, edit the data, and add the image information back to Drone2Map using the GPS Source tool.