| Characteristic | Recommendation |
|---|---|
| Image Side Overlap | 70% |
| Image Forward Overlap | 80% |
| Altitude | Min 400 ft (120 m) |
| Speed | 18 mph (8 m/s) |
| Overshoot | 50 m / 160 ft |
| Terrain Follow | Enabled |
| Image Count | 25 (min) - 1500 (max) |
Before You Go
Rain
Check for rain! Precipitation leads to low-contrast thermal data, and water droplets on your sensor’s lens can obscure RGB imagery.
Wind
Make sure to fly only within your drone’s manufacturer-recommended wind speed. Increased battery drain, blurry imagery, and possible crashes can happen when flying in extreme winds.
Route
Know your route to and from your launch site, and make sure that you have permission to access and launch from your chosen location.
Scan
Have your scan area loaded onto your flight controller and check for any airspace conflicts.
Suggested Gear
A full set of charged batteries for your drone and radio. Ensure that your devices are ready to last for the whole mission.
A laptop or smartphone able to connect to a memory card reader and upload your data to Nova will allow you to begin processing your data while you work.
Multiple memory cards for your sensor allow you to hot-swap and back up your data as you complete your mission.
Thermal Data Collection Tips
- Try to wait until after the sun goes down as thermal contrast will be best once the ground cools down.
- Set your palette to white hot and do not use isotherms.
- Use the high-gain mode on your sensor for increased contrast.
- Try to minimize data collection in the rain as thermal signatures will be muted and your aircraft could be damaged.
RGB Data Collection Tips
- The best data is collected during overcast days which will minimize bright spots and shadows.
- Use the automatic white balance function to make sure your imagery is not too light or dark.
- If your sensor has a global shutter and you are flying low, try flying slower as there is more chance for blurry imagery in that situation.
Overlap Recommendations
The closer you are to the ground, the more overlap we recommend.
If you’re flying higher than 400 ft (120 m) above ground level you can start to reduce that side overlap without seeing distortion in your orthomosaic.
| % Overlap | 1200 ft / 400 m | 900 ft / 300 m | 400 ft / 120 m |
|---|---|---|---|
| Front | 80% | 80% | 80% |
| Side | 40% | 60% | 70% |
Please remember to fly slower at lower altitudes using the recommended speed in your flight planning software when available.
Altitude Recommendations
Try to fly near the maximum legal altitude.
Most consumer drones come with a ~20 MP sensor. At 400 ft (120 m) your orthomosaic will have 0.1 ft pixels, at 800 ft (240 m) your ground sample distance (GSD) will be 0.21 ft, etc.
Adjust your flying height based on the desired GSD and resolution required for the orthomosaic.
Higher altitude reduces GSD but may sacrifice detail, while lower altitude increases detail but requires more flights and processing time.
Speed Considerations
Fly slower at lower altitudes.
The reason for this is that your drone’s camera can only take pictures so fast. If you want to maintain 80% forward overlap, you may need to reduce speed at low altitudes.
Generally 18 mph to 22.5 mph (8 - 10m/s) is appropriate.
Overshoot
Account for orthomosaic distortions.
There will inherently be distortion near the edges of your orthomosaics. This is the result of little to no overlap. Make sure your drone flies beyond the edges of your area of interest (AOI).
We recommend overshooting your AOI by 160 feet (50m)
Terrain Follow
Use automatic terrain follow when possible.
If your drone has the ability to follow terrain altitude, we recommend you use it. Following terrain slows down your mission but improves product quality and equipment safety.