In the past decade, an increased number of humanitarian operations have benefited from the use of unmanned aerial vehicles (UAVs), commonly known as drones. With their higher resolution and flexibility compared to satellite imagery, drones offer an effective way to capture aerial imagery for disaster response, recovery and preparation purposes. Unlike satellite imagery or helicopter-based assessment, UAVs can be deployed within a very short time of a disaster - especially when there is already a skilled local UAV operator in the field.
As with the satellite imagery, drones also come with a range of practical, technical and ethical limitations that should be taken into account when considering their deployment. While many industrialized countries have regulated the use of drones in their legislation, this is not usually the case with the least developed states. This does not mean that one should not check if any national or local regulation exists. For example, flying of drones might not be allowed at the proximity of airports or military sites.
Beyond the legal issues, one should also consider the ethical issues, including the safety of the drones, as well as the accountability to the population in the area of interest. Are the people in the area - possibly just affected by a major disaster - aware if and why the drone(s) is being flown at the proximity of their homes?
Furthermore, as with all humanitarian processes especially in large-scale disasters, a coordinated approach is likely to help each stakeholder to make most out of the drone use. With proper coordination, we can avoid a situation where each actor is deploying their own device, duplicating the effort while leaving behind other affected communities.
The process, steps and tips presented below offer an outline for the utilization of UAVs in humanitarian work. While the legal and ethical aspects apply to any circumstances, the steps can and should still be adapted to best serve a particular project objective.
As with the other technologies supporting the humanitarian efforts, UAVs should not be deployed without careful consideration for the added value they will bring to an operation. Good questions to ask oneself include:
What is the added value of the UAV imagery? Could alternative methods, such as satellite imagery or ground-based assessment do the same job?
Do I have the technical and professional capacity to make use of the UAV imagery? Do I have the sufficient analytical skills to interpret draw conclusions from the findings?
What will be the benefit for the affected communities? How am I going to engage the local communities as part of my operation?
What is the required resolution for the imagery? Is topographic information required? These are important points to take into account as the resolution and further capacity of different UAV cameras vary significantly.
Have I got a proper data management process and workflows in place? Operating an UAV will result in a very large amount of data. In addition to sufficient storage, how am I going to process the data, while keeping the process well-organized? How about separating and securing the sensitive data from that intended for public consumption?
2. Research on the rules and legislation
With the increasing utilization of UAVs across the sectors, more and more governments are adopting formal legislation on the use of such devices. However, this is not yet the case everywhere, especially in the less technologically advanced developing countries. However, even in the absence of formal legislation, there might still be written or unwritten rules that apply to UAVs. For example, unless otherwise stated, it is normally against the law to operate a UAV at the proximity of an airport or military base.
Where no formal legislation on the UAVs exist, the UAV operator should adhere to the rules of the International Civil Aviation Organization (ICAO):
The process of determining and defining a sufficient AoI will depend of the scope and objectives of a project. For example, when mapping of a small-sized individual refugee camp with clear boundaries, this area will also be the AoI. However, in the context of large-scale disasters such as earthquakes or tropical cyclones with impact on multiple districts, there might not be sufficient time to cover all the affected areas. In such situations, prioritization and/or sampling might be required for defining a suitable AoI.
2. Identifying and procuring the UAV operator
In many humanitarian contexts, there might be already a business agreement in place with a relevant UAV operator. However, this is not necessarily always the case, especially in remote areas with low technical capacities. Ideally, as with any humanitarian procurement, a strong preference should be given to local operators, preferably those with a proven track record of quality services. An externally produced operator (including a non-local NGO or INGO) should be used only in case there is no local capacity or technology to deliver the requested services on time.
3. Specifications for the flying process
Variables such as the size of the AoI and the required image resolution will determine the flying distances, altitude and required time. Furthermore, those factors will affect if one or several flying rounds will be needed for capturing the required imagery in the correct resolution.
Normally, the drone operator will have an existing form to calculate the specifications for the image capturing process. In case no, Pix4D, a Switzerland-based photogammetry and UAV specialist company, provides a free form to conduct the calculations:
Depending on the size of the AoI and the image resolution, one or several UAV flights will be required for capturing the requested imagery. The larger the area and the higher the resolution, the longer will be the time needed for completing the UAV flying process. Consideration should also be given for the timetable of the flying process. In post-disaster situations, the type and degree of destruction - such as areas covered by flood water - should still be present. On the other hand, the majority of the UAV cameras are not strong enough for capturing high-quality imagery under rain or snow. Also, extreme cold temperatures may impact the UAV performance.
2. Processing and analysing the imagery
The raw imagery captured by the UAV needs to be further processed in order to make the subsequent data useful for the operational needs. The first step is to stitch the multiple raw images into one unitary orthomosaic - this can be achieved with a commonplace GIS software, including ArcGIS Pro or QGIS. Likewise, there are many online platforms for processing the imagery - some of them also provide the tools to conduct further modelling and analysis on the orthomosaic. Some commonly used imagery processing tools include OpenDroneMap and MapKnitter while others, such as Pix4D or DroneMapper come with a license.
Furthermore, the UAV orthomosaic can be made available on a dedicated UAV imagery sharing platform, such as the OpenAerialMap. When available here, any actor working in the same area can download and make use of the UAV imagery. This could be especially beneficial for long-term recovery or disaster risk reduction projects.
3. Sharing the findings
By making the UAV-derived analysis or other products available for public use, one can serve the entire humanitarian community in the disaster response, recovery and prevention efforts. Moreover, sharing of the analysis (rather than raw or processed data), humanitarian actors without excessive GIS or IM capacity will be able to use the products for their planning and decision-making.
However, certain factors, such as opposition from the local community or government, might prevent public sharing of the products, especially for very granulated data or analysis. On the other hand, sharing of the generalized findings - such as the number of houses destroyed or damaged by a hailstorm - might still be acceptable for all parties involved. Accordingly, as in all other phases, engagement with the local community (and government, where relevant) is essential for achieving a compromise.
In addition to the publication of the products, one should not forget to advertise them on the relevant Skype/Slack/Teams groups, email groups and social media channels (Twitter/LinkedIn/Facebook).
4. Local capacity development
As in almost any part of a humanitarian intervention, operating the UAVs should also come with an aspect of local capacity development. At minimum, this could include improving the data-driven decision-making capacities of the local disaster authorities with the use of the UAV imagery. On a more advanced level, local community members can be trained to become competent UAV pilots. Ideally, this should include a donation of a drone for the use of the community, so that the trained pilots can practice and further improve their skills.
Before the flight
Calculate the cost and benefit ratio. While this involves calculating the costs of the UAV processes, also consider the temporal aspects. How much time can be won with the deployment of a UAV, instead of waiting for suitable satellite imagery to come? What will be the crucial impact on the number of human lives saved thanks to the UAV operation?
Familiarize yourself with the local law and regulations. Does the national or local legislation have any restrictions on the use of UAV? Will I need a permission for the UAV flying process? Also, am I able to use the UAV at all if my AoI at the proximity of an airport or a military site?
Check the availability of local UAV operators. Instead of directly bringing in an external UAV specialist, do you research on the local capacity. The global UAV network, Flying Labs, is a good place to start. Maybe there already a seasoned local UAV operator who could do the same job as I was planning to do?
Check the logistics for bringing your own UAV. In a case you choose to use your own drone, check if there are customs restrictions or any other legal requirements for bringing an UAV into the destination country. Also, especially in case of air travel, check the airline regulations on carrying lithium batteries. Beyond the airport, do you have the appropriate means to access the AoI?
Join a coordination cell. Especially in large-scale disaster settings, there might be already a relevant coordination cell (such as Civil-Military Coordination) where to integrate your UAV flying project. In addition to enhanced coordination and collaboration between the humanitarian actors, the presence in a coordination cell will be advantageous for negotiations with the government, receiving the relevant permits, etc.
Engage with the locals. Inform the relevant local stakeholders, including the local government authorities, about the flying plan. Likewise, as part of the broader community engagement and accountability effort, the plan to use a UAV should be discussed with the concerned communities. The people living in the AoI should be made fully aware of the aims and objectives, along with the concrete benefits that can be achieved with the help of a UAV.
Communicate about your plans. Make the other humanitarian actors about your plan to use a UAV. Perhaps someone else was also planning to do the same in the same area? Proper communication and coordination will help to avoid duplicating the effort and save valuable time for other activities. Ideally, also include a map (or verbal description) about the flying plan.
Consider the weather conditions. If possible, avoid operating the UAVs under rain, snow, fog or full sunshine. Also, extreme cold or hot temperatures may compromise the performance of the device and the cameras.
During the flight
Check that the cameras and all components are operational and free of dirt and damage. This will help to ensure a smooth flying process and maximize the quality of the imagery.
Stick to the designated flying plan, including the take-off and landing points. Deviating from the original plan may not only be illegal but comes with many other safety risk, including collision with a manned aircraft or other unexpected obstacles.
Deploy ground-based spotters for the devices. There should be enough ground-based personnel to monitor the UAV and inform the pilot about possible problems and risks, such as a presence of another manned or unmanned aircraft or assaults against the device.
Keep the landing site clear of obstacles. When other people are present, the landing of the UAV should be clearly announced in advance, so that everyone has enough time to move aside. Especially if the landing site is different from the place of takeoff, there should always be a spotter to ensure a safe landing process.
After the flight
Back-up the data when convenient. Especially in the post-disaster settings, local network might not be strong enough for auto-syncing the imagery in a cloud service. In such circumstances, you should back-up the data on external hard drives as soon as possible.
Keep the public and sensitive data separate. In many cases, the granulated raw imagery may jeopardize the anonymity safety and well-being of the local communities. When such concerns exist, the raw imagery should be kept strictlty separate from the materials intended for public sharing. One way to achieve this is to set up different hard disks or cloud locations for public and private data, and to use the words "Internal" or "Confidential" in the naming of files and folders.
Share your findings. Unless prevented by legal, ethical or practical obstacles, it is good to the UAV-based analysis available to the broader humanitarian community. Sometimes, though less often, this will also include sharing all or part of the raw imagery. Likewise, once available for public, remember to advertise these materials on the relevant communication channels. Do not forget to include the local community in the communication loop.
Test your device. Whether bringing your own drone or using one from an external provider, make sure that you have used the UAV for a minimum of 20 hours. This way, you will be better aware of the possible weak points of the device, and they will not be coming as a surprise in the field settings.
Keep multiple paper copies of the flying permits and other relevant documents. These can be valuable when dealing with the local authorities, communities or other humanitarian actors.
Provide uniforms (such as vests or T-shirts) and professional ID cards and printed mission description for each team member. This way, everyone can easily recognize who you are and which organization you are working for.
Avoid flying the UAV immediately after a disaster. Especially after large-scale sudden onset disasters, manned aircraft will be occupying the airspace to conduct the search and rescue operations. Operating a drone in such conditions can be difficult, even dangerous.
Check your imagery as soon as convenient. As soon as possible, upload some of the imagery to a computer to check if the extent and quality is what you were looking for. In case there are serious
Bring a small photo printer with you to the AoI. This allows quick checking of the quality and overall usability of the imagery, particularly then the imagery will be used for printed products (such as poster-sized maps).