Import and Process Aerial Photogrammetry Data

The Photogrammetry module has been designed to support the importing and processing of UAS data from any drone equipped with a frame-based camera that incorporates a global shutter and produces overlapping geotagged images, regardless of the make and model. TBC includes an extensive list of predefined camera specifications that can be automatically applied when you perform the import. Or, you can import data from drone cameras not stored in TBC by manually entering required specifications (sensor focal length and sensor pixel size) directly into fields provided in the Import UAS Data pane prior to import.

If the data is from a trajectory-enabled UAS, a raw data file containing continuous data with event markers (captured with the on-board GNSS receiver) is also imported. To process the trajectory in the project, you will also need to import a raw data file containing the base station coordinate (Control Quality) that will be used to process the trajectory coordinates.

Note: To perform a trajectory-enabled photo station adjustment, the base station coordinate must be Control Quality. If it is not, a message displays when you attempt to perform the adjustment stating that the trajectory is not of adequate quality to perform the adjustment.

Imported aerial photogrammetry data and image files are typically stored in the TBC project folder. (Note on ECW aerial image files...)

If you are including ground control points (GCPs) in the project to use in the station adjustment, you will need to import them separately as well.

Prerequisites:

See the Subscription Plans page. For a license matrix by command, see the License page in the TBC Community. Also see View and manage licensed features.

To import and process aerial photogrammetry data:

In your TBC project, select the appropriate coordinate system for the data you will be importing. (See Change the Coordinate System for instructions.)
Select the Geoid model quality that best matches the quality of the GNSS data you are importing. For example, if you are importing a high-precision GNSS solution along with the drone data, select Survey Quality. If you are importing general quality GNSS data (typically 5-10m accuracy), select Unknown Quality. This will allow you to create deliverables (point clouds, elevation rasters, and/or orthomosaics) without the need to first perform a manual absolute orientation adjustment, which requires that you measure ground control points (GCPs).
Based on the type of data you are importing, do one of the following:
- If the UAS data includes a JXL (.jxl) file, select Import in Home > Data Exchange or drag-and-drop the JXL file into your TBC project.
  All related UAS data and images are copied into your project.
- If the UAS data does not include a JXL (.jxl file):
  1. Select Import UAS Data in Photogrammetry > Setup (or select Import in Home > Data Exchange, or use drag-and-drop) to import the folder containing UAS data and images into your TBC project.
    The Import UAS Data command pane opens and displays key parameters extracted from UAS image metadata, along with the GNSS quality, if available. (See the introduction to this topic concerning drone support.)
  2. If an alert displays for any fields due to missing data (that is, key specifications that could not be imported from the image files), complete the fields as necessary.
    These custom specifications are saved and re-applied when image data is again imported from the same UAS camera.
    If it can be read from the imported data, the GNSS quality displays. If it is low, you will need to process baselines or measure GCPs before performing an absolute orientation adjustment. If it is high, those steps will not be required. If the GNSS quality cannot be read from the imported data, it is assumed to be low.
  3. If applicable (you know the GNSS quality is high but it could not be read from the imported data), check the Advanced > High quality GNSS check box to specify that the GNSS quality is high, enabling an absolute orientation adjustment to be performed without the need to process baselines or measure GCPs.
  4. When you are done, click the Import button.
  For UAS models that do not produce a JXL file, one is automatically created on import to be used for processing.
If GNSS data is included in the import, the Receiver Raw Data Check In dialog displays.
If the Receiver Raw Data Check In dialog displays, verify and/or select options as described in Raw Data Check-In Options. Then click OK.
An Import Summary report is available for you to review and troubleshoot import errors before you begin processing.
Optionally (if applicable), process GNSS baselines from imported RTK data using these steps:
1. Do either of the following:
  - If you were provided a .T02 file to be used to process baselines in the project, import it now.
  - If you were not provided a .T02 file to be used to process baselines, use the Internet Download command to download files from the reference station closest to the project data. (See Download and Import Internet Data for instructions)
2. Use the Process Baselines command to process baselines. (See Process Baselines.)
Optionally (if applicable), import a data file (for example, a CSV file) containing ground control points (GCPs) data to be used in station adjustment.
Adjust the aerial survey photo stations as described in Adjust Aerial Survey Photo Stations.
Optionally, you can send the data to UASMaster for processing and deliverables creation. See Import and Process Aerial Photogrammetry Data Using UASMaster.
Create deliverables as described in Create Aerial Photogrammetry Deliverables.

Note: If necessary, you can merge multiple flight missions into a single mission after import. See Merge Aerial Survey Flight Missions for instructions.