Final tests of CLOSE-SEARCH: unmanned aerial platforms in search missions for lost people

Final tests of CLOSE-SEARCH: unmanned aerial platforms in search missions for lost people
The project CLOSE-SEARCH, lead by the Institute of Geomatics (Spain), reaches its end presenting a unmanned vehicle prototype conceived to detect people lost in difficult-to-access areas by means of the body heat.

Using an advance navigation concept based on the European augmentation system EGNOS and low-cost redundant inertial measurement units, the UAV (that is, Unmanned Aerial Vehicle) scans areas determined by the Search-And-Rescue (SAR) team –the scan is performed combining RGB and thermal vision: that means, seeing and sensing the target. With almost 2 meters length, an approximate weight of 75 kilos and capacity to carry up to 30 kilograms of payload, the helicopter is complemented with a ground control station in which two operators control the mission, not just the scanned surface but also monitoring the status of the vehicle, and finally links with the emergency teams in place by providing accurate positions of the sensed targets. This concept can therefore be fully integrated in the actual SAR mission work flows.

The vehicle control is fully autonomous: given an alert and an initial guess of the area where the person got lost, the SAR team defines the route to be followed and the vehicle executes the take-off, search, return to base and landing automatically. The Civil Protection Directorate of Catalunya (DGPC) participates in the project leading the User Advisory Board, a group of experienced end-users in the SAR field, in order to incorporate their experience in real-life situations. The DGPC has also arranged the test sites for the tests and demos in the project, as the one held just a week ago in the town of Copons.

Innovation in the use of UAVs: robust navigation and Beyond-Line-of-Sight communication

The Institute of Geomatics (IG) brings to the project a navigation concept for unmanned platforms based on the fusion of various sensors: on one side, a key component is the use of the GNSS satellite-based augmentation system, European EGNOS, bringing position accuracy down to 1 meter in horizontal and 3 meters in vertical (95%) and providing integrity, which is the fundamental measure of safety related to navigation. The use of integrity for UAVs is novel and already some papers have been published by IG in the frame if CLOSE-SEARCH. Another component of the navigation system is the Redundant Inertial Measurement Units (RIMUs), brought in by the École Polytechnique Federal of Lausanne, to investigate the use of low-cost inertial technology, used in a robust configuration to fit the high-safety degree of the navigation system. Finally, other sensors as Barometric Altimeters and Magnetometers are used to provide height and attitude control. The result is an unmanned platform featuring a low-cost, robust navigation system which incorporates integrity as a measure of safety in navigation. Another innovative aspect of the prototype is the use of Worldwide Interoperability for Microwave Access (WiMAX) as a primary means for communication between the UAV and the ground control station. The Asociación de la Industria Navarra (AIN), creators and operators of the base platform, bring this communication technology to the project to demonstrate the validity of the so-called Beyond-Line-Of-Sight (BLoS) communication (that is, communication which does not require physical clearance between the emitter and the receiver). The use of such a technology would allow the platform to operate in zones of terrain abruptness without restrictions on the particular UAV-control station geometry. Such an approach is not yet implemented in conventional UAVs, which at the present time are limited by distance and obstacles.

Lower cost and risk, more applications and functionalities

The use of unmanned aerial vehicles in SAR missions has become consolidated during the last years, especially in vast, low populated areas such as in Canada or Australia. Generally, these systems are of less cost and the impact of a platform loss or the risk to which human operators are exposed is lower than with its homologous manned versions. During Katrina hurricane in New Orleans (2005) or the nuclear tragedy in Fukushima (2011), the unmanned vehicles were in charge to provide aerial imagery of the scene, being able to approach much closer that ground teams or manned helicopters and planes, or even flying restlessly during night. Particularly in CLOSE-SEARCH, the nocturne operability was a strong and key requirement to be demonstrated, as the users clearly identified its convenience and advantage over other search means. Therefore, the Final Test Campaign covered this item among others.

The Final Test campaign: demonstration of end-to-end SAR service

During the first weeks of March, the final version of the prototype has been tested and the main functionalities of the prototype have been demonstrated. The first part of the testing campaign was carried on in the town of Copons, in central Catalunya. In this location, the BLoS communication concept was tested and several users were able to assess its performance in a real situation. In addition, a search mission was simulated over a remote area: few persons were hidden and the operators in ground had to identify those persons by means of the imagery that the UAV sent to the station. Finally, these persons were geo-referenced to know their exact locations. A second test was carried in Pamplona to assess the capability of the night operability of the prototype and capacity to sense targets also during night.

The CLOSE-SEARCH project (, funded by the European Comission under the 7th Framework Program, is lead by the Institute of Geomatics and gathers Asociación de la Industria Navarra (, École Polytéchnique Fédéral de Lausanne (, DEIMOS Engenharia (, Institut Cartogràfic de Catalunya ( and Direcció General de Protecció Civil (

Here, the press releases out the CLOSE-SEARCH tests in El Periódico de Cataluña and also in TV3.