Applied Research on Drone Detection
Recently, many cases of unmanned aerial vehicles (UAVs or drones) invading airports or flying in the route of airplanes have been reported. In some cases, the invasions caused millions of dolars in loss due to the airport runway closure. In other cases, the drones also hit the airplanes putting lives at risk and also causing damage. In the LASP we apply the theory of array signal processing for the detection of drones.
When a signal emitted from a drone reaches an antenna array its direction can be estimated via relative phase difference or relative power difference between the antennas. In the case of relative phase diference a uniform linear array is used. An example of experiment campaign using the ULA is shown in Figure 1 where the relative phase difference is used to compute the direction of Arrival (DoA).
|Figure 1a. Experiment using a ULA in an open field||Figure 1b. Field experiment using a directional antenna array|
In the case of relative power diference an array of directional antennas is used. Each antenna points towards a different direction so the antenna with highest power gives a clue about the position of the drone. Afterwards, power measurements are processed to give more accurate estimates. The picture of an experiment using this type of antenna array is shown in Figure 1b. An example with the estimated DoA using a directional antenna array is seen in Figure 2.
Figure 3. Results of DoA estimation