Airteam provides its customers with highly accurate planning data for roofs and building envelopes by means of drone surveying. The accuracy of the results can be seen in the following table.
Various factors, which are explained in this article, can have an influence on the final results. Airteam has developed the first and so far only DIN-SPEC for digital roof measurement by drone.
| Camera resolution & positioning | Drone < 20 MP (GPS) |
Drone with min. 20 MP (GPS) |
Drone with min. 20 MP, (GPS+RTK) |
| Measuring accuracy (%) |
not covered by DIN SPEC 5452-5 | 99,64% | 99,91% |
| Measuring accuracy (absolute) | 15 cm * | 10 cm ** | 3 cm *** |
* possible; measurement accuracy depends on a variety of factors including GPS, distance to the object, lighting conditions, etc.
** Mean square error for distances under 40m; see also DIN SPEC 5452-5
*** even better results are possible; see also DIN SPEC 5452-5
Sensor and camera
Drones used for roof surveys are equipped with high-quality sensors and cameras. These sensors capture data with a high accuracy of just a few centimeters, depending on the model and configuration. Airteam recommends drones with a resolution of at least 20 megapixels in the corresponding flight modes (interval, hyperlapse, etc.) and a sensor size of at least one inch.
Image material
In addition to the quality of the images, the way in which they are taken also plays an important role in their accuracy. Drones produce an optical measurement, which means that the roof surfaces and building envelopes can only be accurately reproduced in planning files if the images were taken according to certain specifications. A high degree of overlap and a sufficient number of individual images are important here. The drone pilot guides with the specifications for drone flights can be found in the following article: Drone guide: DJI Fly App
The weather and good lighting conditions can also have an influence on the final result.
Reference dimensions
To validate the measurement results, you can also lay out or take reference measurements on the object to be measured. For example, a meter stick (2-5m) can be used to place a very good reference on or next to the roof during the drone flight in order to check the results afterwards. You can also take reference measurements of the roof or façade on site and compare them with the drone measurement data.
GPS & Real Time Kinematic (RTK)
Most drones use GPS to determine their location. Very good results can already be achieved with this technology if there is a stable GPS connection to sufficient satellites during the flight. However, if you want even more precise measurements, you can install additional RTK modules on higher-class drones (e.g. Mavic 3 Enterprise). RTK is a high-precision positioning technology that is used in GPS receivers to provide location data with extreme accuracy of a few centimetres in real time and is already widely used in surveying. In conjunction with the GPS data, the accuracy of the drone's data can be significantly increased.