How to choose your professional drone

What is the best professional drone for performing inspections of linear infrastructure?

Currently, there are around twenty manufacturers of civilian drones worldwide, each offering approximately one hundred models of production drones. These drones all have different technical specifications to best fulfill specific missions. To choose the right professional drone for your needs, you must first create a detailed specification document outlining your intended activity. This will allow you to select the best professional drone by choosing the most suitable technical and hardware solution.

Professional drone: fixed wing, multirotors or balloon?

The DGAC has classified the various specific activities of a drone operator into several areas of activity: (i) Audiovisual – Advertising – Entertainment, (ii) Agriculture, (iii) Topography – Mapping, (iv) Monitoring of linear infrastructure, (v) Inspection of structures, (vi) Real Estate.

Each of these domains requires different operational criteria, the most important of which we have listed below: (i) Flight in urban area (or not), (ii) Accuracy around takeoff/landing areas, (iii) Need for hovering to perform image capture, (iv) Desired nominal flight altitude (should the vector be invisible during shooting).

These initial operational criteria should already allow you to easily determine the class of your aircraft (balloon, airship, helicopter, multirotors, fixed wing).

In this post, we will focus on professional drones dedicated to the inspection of linear infrastructure. This particular activity often requires the ability to take multiple close-up shots of the infrastructure from different angles (impossible for a fixed-wing drone) AND to cover long distances (impossible for a balloon), so your aircraft will need to be a multirotor.

What type of sensor should you use on your professional drone?

Different types of sensors are used to take pictures (this depends on the nature of the analysis desired).

These sensors, using acoustic or electromagnetic waves, are divided into: (i) Optical cameras, (ii) Thermal and/or infrared cameras (to detect temperature failures on an electrical installation, insulation defects or thermal leaks), (iii) Terahertz cameras (vision inside composite materials), (iv) Multispectral cameras (recording simultaneous images on several wavelengths), or (v) Lidars (recording 3D images in the form of point clouds).

The operator will have to list the sensors needed to carry out the missions targeted within the framework of its specific activities.
However, vectors are compatible with very few sensors. Indeed, many parameters must be validated at this level:

• Is the weight of the sensor less than the payload of the vector?
• Can the sensor be attached to the drone's gimbal AND controlled from the aircraft's remote control?
• Are the vehicle's safety systems sufficient to guarantee sensor protection in case of a vehicle crash (some sensors are very expensive – around one hundred thousand euros)?

In our illustration, the operator wishes to obtain basic aerial images of its infrastructure to assess its state of disrepair. An optical camera with 1080p HD resolution (1920 x 1080) is sufficient.

Many HD optical cameras are natively integrated into many vectors (notably for DJI drones).

Consequently, it will not be necessary to turn to higher-end manufacturers such as Freefly Systems Inc. (specializing in cinematographic shooting), Hélicéo (specializing in topographic shooting) or Yuneec (which incorporates higher-end optical cameras).

What is the mission range for a professional drone?

During inspections of linear infrastructure, the operator may be required to intervene in an urban or rural area (with beyond visual line of sight). Their specific activity may therefore be subject to operational scenarios of type S2, S3, or even S4.

However, the vehicles must be approved by the DGAC to be able to operate under these operational conditions (which is not the case for all production drones).

Furthermore, the operator will want to benefit from the greatest possible operating range. As the infrastructure is linear, the performance criterion to be studied here will be neither flight autonomy nor the operating range of the aircraft, but the range of the radio control (limiting factor), often limited to less than 8 km (which would allow inspection from a point of approximately 20 km of line).

In the table below, we have compared four DJI drone models.

As the table above shows, when choosing the best professional drone, the limiting factor of the mission is not the range or the radio control range, but the approved operational scenario.

In our case, selecting a Mavic Air 2 drone for this type of mission is not optimal because all flights must be conducted within visual line of sight (at a maximum distance of 200 meters from the remote pilot). Similarly, selecting a Matrice 300 RTK drone is also not optimal because its battery life will not be fully utilized (the mission's maximum range is 4 km, as the drone is not S4 certified).
In our illustration, it would be wise to select a Phantom 4 PRO V 2.0 drone.

Geolocation and time-stamping of aerial drone footage

Large clients often want to create a comprehensive video library of their network infrastructure within their Geographic Information System (GIS). To achieve this, it is critical to be able to time-stamp and geolocate all frames of the aerial videos recorded.
However, this data is becoming less and less available from aircraft manufacturers.

Conclusion

The inspection of linear infrastructure is currently constrained by two key parameters: (i) Identifying an approved S-4 vector to quintuple the range of missions, AND (ii) Having a system that allows geolocation and time-stamping of the sensor's video stream in order to be able to exploit it in the client's GIS.

What can the DRONECONTROL embedded system offer you?

DroneCONTROL offers drone operators the ability to: (i) Time-stamp and geolocate aerial footage, (ii) Retrieve the drone's video feed in real time, and (iii) Secure aerial recordings by bypassing video storage on the drone.

Feel free to contact us to find out which is the best professional drone for your field of activity.