![]() Using a chirp jammer, a truck driver can, for example, drive around undetected by the GPS trackers on the truck and car thieves can disable GPS anti-theft devices on stolen vehicles. These devices though illegal are cheap and can be readily acquired on the internet. In the case of UAV inspections of wind turbines for example, many countries encourage windmills to be built next to roads, a situation that increases the chance of interference from in-car chirp jammers. In the sky, the signals from jammers can propagate over far longer distances than they would be able to on land. ![]() GNSS receivers on-board UAVs can be particularly vulnerable to external sources of interference, be they intentional or not. For the quadcopter installation in this example, the loss of RTK was readily diagnosed and solved by placing the camera in a shielded case while the quadcopter was still in the workshop. At the installation stage, being able to view the RF spectrum is an invaluable tool for both identifying the source of interference and determining the effectiveness of measures such as modifying the setup or adding shielding. As well as mitigating the effects of interference, AIM+ includes a spectrum plot to view the RF input from the antenna in both time and frequency domains. The three peaks are exactly 24 MHz apart pointing to their being harmonics of a 24 MHz signal: the typical frequency for a MMC/SD logging interface.Īn AsteRx receiver was used in this setup which includes the Advanced Infererence Mitigation and Monitoring AIM+ system. The restricted space means that the GNSS antenna is often in close proximity to other electrical and electronic systems.įigure 1: GoPro Hero 2 camera pick-up monitored by an AsteRx4 receiverįigure 1 shows what happened to the GPS L1-band spectrum when a GoPro camera was installed on a quadcopter close to the GNSS antenna without sufficient shielding. Self interferenceĪ significant source of interference on UAVs is often the other components installed on the UAV. In the most extreme cases, interference can result in complete loss of signal tracking and positioning. At the very least, disruptions to satellite signals can degrade position quality causing fall-backs from high-precision RTK and PPP modes to less-precise modes. One of the biggest threats to drone safety is GNSS interference. When things go wrong, the consequences are invariably much more serious than they would have been on the ground. No longer the preserve of specialist drone users, applications using drones have been venturing into areas such as survey, inspection and volume analysis with an impact that is little short of revolutionary. Recent years have seen the appearance of affordable, high-end drones which, coupled with easy-to-use mission-planning tools, has created the perfect environment in which drones can flourish. But will jamming spoil all the fun? Who let the drones out? It’s no wonder that drones equipped with GPS technology and remote sensors are revolutionising data collection. Russia is currently availing itself of the technology to jam commercial planes in Ukraine.Self-interference affects drones with many electronic devices located close to the GPSĬollect 1 million data points from a 15-minute flight compared to 300 points in a day from a traditional ground survey. Statistics are harder to come by in the United States, but there can be little doubt the devices are prevalent and widely used. In Mexico, jammers are used in some 85% of cargo truck thefts. The typical jammers used for cargo hijackings are able to jam frequencies from up to 5 miles away rendering GPS tracking and security apparatuses, such as those used by trucking syndicates, totally useless. Jammers work by overpowering GPS signals by emitting a signal at the same frequency, just a bit more powerful than the original. The core problem for any system using GPS is that the signals are extremely weak, an inevitable byproduct of the vast distances those signals need to travel. In case you aren't a master criminal or a secret agent, here's some background. Wouldn't it provide some peace of mind if you could check your child's location at any given time? The best GPS trackers and devices for kids
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