How To: Use Geospatial Log Files from Video Flights Captured with ArcGIS Flight

Summary

Whereas Site Scan and ArcGIS Drone2Map can apply photogrammetric processing to still imagery to create orthomosaics and other high fidelity products, video media presents a different challenge.

ArcGIS Flight can record GPS data and camera orientation during a flight. This information is stored in a CSV file referred to as the Geospatial Video Log (GVL), which can be used within ArcGIS applications to manage, view, and analyze the video on a map.

ArcGIS has two different environments for working with video and its corresponding GVL file:

If the video is aimed (primarily) toward the ground, the video footprint may be shown on the map using Full Motion Video (FMV) within ArcGIS Pro. This capability requires the Image Analyst Extension for ArcGIS Pro, and a post-flight process, known as multiplexing, must be applied using the Video Multiplexer geoprocessing tool. The Video Multiplexer embeds the flight telemetry data from the GVL file into the video file. Refer below to FMV workflow in ArcGIS Pro. Note that the accuracy of the georeferenced video depends on the hardware available in the drone.

If the video is aimed (primarily) toward or above the horizon, the video footprint may not intersect the ground, but the camera location and orientation can be managed in ArcGIS using what is referred to as an Oriented Imagery Dataset.

Procedure

To use the Video Multiplexer tool in ArcGIS Pro, two corresponding files are required:

A video file
A Geospatial Video Log (GVL) file

To obtain video files for a mission:

Ensure that the newest version of ArcGIS Flight is installed.
Open the Flight app on the tablet and select a project.
Select a flight mode for your mission. This can be an autonomous flight or a manual flight using Inspection mode.
Prior to takeoff, enable Video Mode within the Mission Settings menu. Geospatial Video Logs will automatically be recorded in Video Mode.
Complete your mission.
After the mission is complete, remove the SD card from the drone and copy the appropriate video files to a computer for postflight processing. File names for videos are similar to the following: DJI_YYYYMMDDHHMMSS_0038.mov

To obtain GVL files for a mission:

Use the main settings in ArcGIS Flight to access a list of all GVL files. From the project home tap the gear icon in the top right corner.
From the Settings menu select Geospatial Video Logs.
Tap Select from the top right corner of the Geospatial Video Logs window.
Tap to select the GVL file(s) associated with your mission. Selected missions will be highlighted and display a checkmark.
- For each GVL in the list, the associated project and mission are beneath the file name in the following format: "Project Name (Mission Name)".
Use the Share button to view the list of export methods.

Note:
When sharing the GVL files, they are put into a .zip archive. When sharing a single GVL file, the .zip archive has the same name as the associated video file with .zip on the end: "DJI_0881_YYYY-MM-DD_HH-MM-SS_videolog.csv.zip". When sharing multiple GVL files, the .zip archive uses the current date with .zip on the end: "SiteScanVideoLogs_YYYY-MM-DD_HH-MM-SS.zip".

FMV workflow in ArcGIS Pro

Ensure that ArcGIS Pro version 2.4 or later is installed on the computer, and that the Image Analyst extension is licensed and enabled.
Open ArcGIS Pro, and in the Catalog window, right-click Folders, and select Add Folder Connection.
Browse to the folder containing the files copied from ArcGIS Flight (the video file and its corresponding GVL file) and select OK.
Run the Video Multiplexer geoprocessing tool by adding the video file (.mp4) into the Input Video File field and its associated GVL file (.csv) into the Metadata File field.
Type a filename for the output video file. For example, you can type inputfile_multiplexed.mp4 for a file in MP4 format, or a *.ts extension for files in Transport Stream format.
- Optionally, to follow best practices for FMV it is recommended to enter a DEM representing orthometric height, referenced to sea level, into the Video Multiplexer. This helps support future geospatial searches of multiple video files, but is not a required step. If a DEM for the project area stored as a local file is not available, use the World Terrain from the ArcGIS Online Living Atlas. Alternatively, a single value for the average ground elevation of the project area can be entered.
When the new video file is complete, it can be added into a 2D map or a 3D scene in ArcGIS Pro.

Note:
When viewing the file in ArcGIS Pro, if the video footprint does not appear to be the correct size, refer to the article: How To: Correct drone flight altitude data in Geospatial Video Log (GVL) files in ArcGIS Flight

The GVL file and FMV assume the drone is reporting flight altitudes as height above ellipsoid (HAE), but if the data is referenced to orthometric height (above sea level, ASL) or height above ground level (AGL), the height values may not be interpreted correctly by the Video Multiplexer.

Known limitations

As of ArcGIS Pro version 2.6, the FMV video player performance is not optimized for high-resolution 4K video. It is recommended to test different video resolutions to evaluate playback performance in ArcGIS Pro to decide the best resolution for data capture.

For more information about FMV in ArcGIS Pro, see the Related Information section.

Generating Oriented Imagery Dataset with Imagery Captured in ArcGIS Flight
In certain cases, imagery can be incompatible for processing using the ArcGIS Reality engine due to improper overlap, harsh oblique orientation, or insufficient metadata. Oriented Imagery provides an alternative for such non-traditional imagery, allowing for the management and visualization of imagery captured from any angle. Oriented imagery datasets can be explored using one of the following ways: