MyDefence WATCHDOG 250

The WATCHDOG 250 from MyDefence (Denmark) is a passive, stationary RF drone detector with a 90-degree sector in an IP68 housing. It receives the radio links of drones within its sector and reports them. The manufacturer names critical infrastructure, prisons and military use as fields of use.

The stated range is up to 9 km, a maximum under favourable conditions: the range of a passive detector depends on the drone’s transmit power, line of sight and radio environment, and in built-up terrain it is shorter. One unit monitors 90 degrees horizontally; all-round cover therefore takes four units. IP68 means dust-tight and protected against continuous immersion. Power draw is below 15 W.

The detector does not transmit and does not interfere with the drone’s radio link. Whether and how receiving and evaluating third-party radio signals is permitted (secrecy of telecommunications, data protection) has to be clarified for Germany and Poland before use. Jammers may be operated only by authorities in Germany and Poland (Section 91 TKG, Article 42 of the Polish Electronic Communications Law).

In selection the sector decides: one unit sees only 90 degrees, and aiming it at the area from which drones can arrive is the most important installation decision. The 9 km is a maximum; with terrain and buildings, plan on less. The low power draw eases the power supply at the mast. Seals, connectors, antenna alignment after a storm and upkeep of the signature library need checking. The detector does not see drones that do not transmit.