Skip to main content

Help from the skies

By GeoConnexion - 26th August 2020 - 13:32

UAVs are a great tool for emergency responders. But getting them to situations quickly, safely and automatically will take accurate positioning information and navigation, writes Ellen Malfliet

“112, what’s your emergency?” It is a busy afternoon in the emergency centre. A call comes in describing a road accident on a remote highway along the coastline. The dispatcher locates the approximate location on a map and creates a flight path that automatically gets routed to the nearest UAV.

Kilometres away, a sleeper UAV automatically dispatches towards the scene of the accident, scoping the situation. Minutes after the initial call, images from the scene reach the emergency centre. The dispatcher knows exactly which materials to send to get the situation under control.

Sounds like science fiction? It could be reality in the next couple years.

UAVs can be a great tool for emergency responders to reply faster to emergency situations and to assess the situation to dispatch the proper services and materials. This is especially important in areas that are difficult to reach. Distance is a very important dimension. The response needs to be immediate and fitting to the situation at hand. Underestimating the materials needed for the situation creates problems down the line, as the ambulance or fire crew discovers it is underequipped to tame a rapid escalating crisis. Likewise, materials that are dispatched unnecessarily can be sorely needed elsewhere.

UAVs offer a solution: quick, cheap and easy to dispatch, they can cross vast distances in minutes without being hindered by challenges in the terrain such as bodies of water or dense forests.

The use of UAVs in emergency management requires a new approach, where their management does not take up additional resources but is instead integrated into the responders’ existing dispatch platform. As soon as the emergency call is received in the control centre, the dispatcher generates a flight path. The system validates and refines this trajectory, taking into account stable information such as legislation as well as constantly changing data such as weather conditions.

Wireless communication channels

The geospatial aspect is of vital importance. Safe execution of automated flight means the UAV needs to have 100% clarity about where it is going and what to do if connection is lost. Procedures for handling “loss of communication” involve sending an emergency response team after the UAV to re-establish communication a fixed timeframe after it is lost.

To ensure there is sufficient positioning accuracy, two wireless system come into play. A double connection is created with a wireless navigation system to satellites in space and a wireless communication system to ground-based radio networks (LTE). Both are necessary and work in sync: the satellite system provides the positioning data, whereas the ground-based network transfers these data onto the internet for others to see in real-time. Flights beyond visual line of sight require tracking via qualified ground equipment.

A space-based radio network is made up of satellites that can communicate with devices on Earth. A space-based radio network also includes ground-based infrastructure for maintaining the satellites and so on. Communication with a space-based radio network requires one or more satellites to be within radio range of the Earth-based device – understood to be an obstruction-free path between the Earth-based device and satellite, as generally the frequencies chosen cannot pass through objects.

The most common types of space-based radio networks are navigation – GPS, GLONASS, Galileo and BeiDou – and communication. Navigation is a requirement for almost all UAVs if they fly automatically on trajectory or mission flights. It is unsafe but possible for a UAV to fly without a communication system, as only the last known position is available and remote control is not possible.

A ground-based radio network consists of base stations placed in a mesh network to provide direct radio communication with devices in a specified geographical area. The existing 4G mobile network provides an internet connection to make the tracking information available to the community. Other tracking systems commonly used in aviation, such as FLARM or ADS-B, lack the necessary certified ground infrastructure to send tracking information to the internet. Moreover, widely deploying those systems would require an extensive deployment of new antenna infrastructure.

Since no affordable tracking system for UAVs was available, Unifly developed BLIP in compliance with the ASTM standards and the new European UAV legislation. BLIP receives positioning information from satellites and broadcasts its position over 4G: the satellite communication protocols accept the tracking information, the 4G network makes it available to the ecosystem.

The use of a tracker such as BLIP that combines various satellite communication protocols enhances the positioning accuracy. The BLIP devices send binary tracking data over the LTE 4G mobile network using encrypted data. A data collector reads, checks and decrypts the incoming data from the BLIP, converts the data to JSON format and forwards it to Unifly’s Public REST API to make it available to other applications, including the UTM platform, the operators or third-party real-time mapping software.

In addition to the transmission of tracking data, BLIP broadcasts the UAV’s Remote Identification, 3D location and take-off position over Bluetooth Low Energy in compliance with the European Delegated Regulation and ASTM F3411 standard requirements for UAV flights. The broadcast data can be assessed in real-time by the general public using a mobile scanner app and by law enforcement personnel through the use of a secured application on a mobile device.

Back to our control centre. The dispatcher creates the mission and the call is sent to a distributed UAV network. UAVs are activated and programmed to fly to their destinations when needed. This requires an integration between the flight controller and the UAV management system to support fully automatic autonomous operations.

The dispatcher creates a corridor, a temporary no-fly zone along the UAV’s path. Much like an ambulance today weaves its way through a traffic jam, an emergency UAV needs to take priority over other UAV traffic in the area. To ensure this path is cleared, the system immediately communicates the UAV’s trajectory to all other users. Creating the flight path and outfitting the UAV with a tracker provides a high level of accuracy and remote control. This, in turn, eliminates the need for a local pilot.

The future is bright

UAVs can provide a clear benefit to emergency management. An immediate and accurate scope of the situation at hand leads to better, faster deployment of the right materials. The safe integration of UAVs in the wider ecosystem is a condition of paramount importance to take full advantage of the economic, societal and environmental benefits UAVs have to offer.

Ellen Malfliet is CMO at Unifly (

Download a PDF of this article


Read More: Unmanned Aerial Vehicles