This article explains how to use a drone to capture roofs and generate accurate 3D measurements for PV system design. The instructions are based on the DJI Mini 4 Pro and other DJI Mini models.
You can use the photos from this process with our 3D Building Survey Service to create a 3D model for PV planning.
1. On-site Preparation
Choose a safe take-off spot (flat and obstacle-free).
Carefully unpack the drone and remove the gimbal protector.
For controllers with smartphones:
Connect your phone, launch the DJI Fly App (tablet also possible for better visibility).
For controllers with a built-in display:
Turn on the controller and connect it to the drone.
Ensure GPS and compass are calibrated before flight.
2. Take Overview Photos (Optional but recommended)
These images help document the site and support the later 3D reconstruction.
Fly approx. 10–20 m above the roof and take 5 photos:
Top-down photo (camera at 90° down), roof ridge centered under the drone
2–5. Four angled shots from all sides (camera angle approx. −45° to −60°)
Tip:
Photo 1 can also serve as a 2D planning base.
Use automatic camera settings for optimal exposure.
3D Measurement Using Hyperlapse Orbit Mode
This is ideal for square or compact buildings (e.g. single-family homes, row houses).
Step-by-step:
Set POI (Point of Interest):
Tap the roof center on the screen or press the C1 button on the controller.Set gimbal tilt: −45° to −60°
Move the drone slightly away from the building (not directly overhead)
Ensure the camera captures both roof and facade.Activate Hyperlapse Mode:
App > Window icon > Hyperlapse > CircleHyperlapse Settings:
Interval: 2 seconds
Length: 3–4 seconds → ~75–100 photos
Speed: 0.5–1 m/s (max. 2 m/s)
Format: JPEG only (no video!)
Start recording with the red button.
The drone will now orbit the building and take photos.
You can adjust height and camera angle during the flight.
Tips:
Use the left wheel on the controller to adjust camera tilt.
Avoid obstacles (trees, vehicles, birds).
For large projects: increase length to 6–8 s for more images.
3B. Alternative for Larger or Rectangular Buildings
Orbit mode may not suit larger buildings (e.g. apartment blocks, industrial sites). Instead, use:
Oblique mode
Smart Oblique
3D Photogrammetry / Double Grid
Setup:
Define the flight area in the app (polygon)
Gimbal tilt: −45° to −60°
Image overlap:
Side: 70%
Forward: 80%
Altitude: Not too low — include both roof and facade in the frame
4. Post-Flight Quality Check
Check your images:
Are all roof areas and details visible?
Any cut-off edges?
Are images sharp and well exposed?
Confirm images are in JPEG format, not video
Are facades visible (if needed)?
Optional:
Capture extra photos of smaller objects (e.g. lightning rods).
5. Save & Upload Your Photos
Connect the drone via USB-C or remove the SD card
Navigate to:
DCIM > HyperlapseCopy the images to your computer
Optionally zip the files
Upload to the 3D Building Survey Service in autarc
(Guide available in the Help Center)
6. Tips & Best Practices
More images = better model quality
Re-set POI if you get an error
Don't fly too close — context (roof + facade) improves results
More camera tilt = more facade, less roof
Use oblique flight for very large or long buildings
Always fly parallel to the building for better overlap
Gimbal tilt: –45° to –60° for angled shots