A KML file is more than a deliverable artifact. It’s a spatially organized quality record — every photo placed at the GPS coordinates where it was captured, with the camera’s orientation shown, with the coverage overlap calculated for each frame. When it’s done right, a client or project manager can open it in Google Earth and immediately see exactly what was captured, where the gaps are, and whether the data quality is acceptable.
FlightDeck builds this automatically for every flight sub-folder in your project, using the EXIF and XMP metadata embedded in your photos by the drone.
What Goes Into Each KML
Phase 2 of the QC Uploader workflow is KML generation. For each photo in the dataset, the KML generator reads GPS coordinates, absolute altitude, and gimbal orientation data — pitch, roll, and yaw — and places a camera icon at the exact position where the photo was taken, pointing in the direction the camera was aimed.
Each camera icon has a view frustum that visualizes the gimbal direction. You can see at a glance whether the cameras were consistently pointed at the structure or drifting, and whether the angular coverage around a tower is complete.
The icons are color-coded by overlap percentage:
Green indicates 80% or higher sequential overlap — sufficient for photogrammetry deliverables and structural documentation. Yellow indicates 60–79% overlap — marginal, worth reviewing before delivery. Red indicates below 60% overlap — a gap in coverage that should be flagged for a potential re-fly.
The Extended Data Balloon
Clicking any camera icon in Google Earth opens a data balloon with the complete record for that photo: site ID, camera make and model, aperture, ISO, shutter speed, focal length, GPS coordinates, absolute altitude, AGL altitude, gimbal angles, aircraft orientation, overlap percentage, and QC pass/fail status for aperture and ISO.
This extended data is what your QC report, your client review, and any formal documentation can reference. Every measurement is directly from the drone’s embedded metadata — not derived or estimated.
Altitude Display Correction
KML files use absolute altitude mode, which means camera icons are placed at their GPS-recorded altitude relative to the WGS84 ellipsoid. Google Earth renders its terrain surface using SRTM data, which uses a different altitude reference. Without correction, camera icons may appear several meters above or below the actual terrain surface in Google Earth.
FlightDeck corrects for this with an Altitude Display Offset — an additive value in meters applied to every photo’s altitude when writing the KML coordinates. Set correctly, this makes camera icons appear at the right elevation relative to Google Earth’s terrain. The offset applies to both camera icon positions and any laser rangefinder target altitudes in the dataset, so the entire KML is consistent.
The Geoid Calculator tool in FlightDeck derives the correct offset for your specific survey area from Aeropoints GCP data — more on that in a separate post.
Single-Dataset Mode
On a large project, you may need to re-generate the KML for just one sub-folder — maybe a site was re-flown and you have new photos, or you’re adjusting the altitude offset for a specific location. The Dataset Selection filter in the QC Uploader limits KML generation to the selected sub-folder without touching the rest of the project. Clear the selection to process all folders again.
Why This Matters Beyond the Deliverable
The KML isn’t just for the client. It’s for your own QA before delivery. Opening the color-coded KML after a flight and before upload lets you verify coverage, spot the red icons that indicate gaps, and make the decision to re-fly before the job is closed out.
Catching a coverage gap from the Google Earth view is a quick conversation with a project manager and a targeted re-fly. Catching it after the client has reviewed the delivery is a different conversation entirely.
The KML generation in FlightDeck builds this review layer automatically, without requiring external GIS software or manual file preparation. It’s one of the outputs that tends to get noticed — clients who receive well-structured KML files alongside their photo deliverables understand that the data was reviewed and organized before it reached them.
FlightDeck’s KML generation is included in every license tier. Try it free for 30 days.