precisejammers

　　It might be a bit mystifying to some as to why someone might want to jam a GPS signal. However, there are those with a particular need for privacy, be it to massage their paranoia, keep law enforcement from engaging in warrantless car tracking, take an unauthorized lunchbreak with a GPS enabled company car, or a teenager not wanting their parents to track their GPS phone. Whether this is all legal or not is an entirely other question.

　　The basic purpose of a GPS signal jammer is to prevent GPS loggers from either receiving satellite signals, or sending signals back to their base station. Now, chances are, any GPS you will have contact with use the radio frequency set aside from civilian use.

　　The GPS signal jammer works by sending out its own signal on the same frequency as the GPS unit, a noisy signal that prevents it from receiving or transmitting any useful information. There are a number of types of noise signals it can send; some call for a narrowband Gaussian signal, others for a simple continuous wave.

　　GPS signal jammers come in a variety of designs, each suited for slightly different uses. The first, and most popular model to hit the mainstream market was one that plugs into the cigarette lighter of a car, effectively disrupting the signal for a 15 foot radius. Not enough to disrupt signals from other cars, but enough to keep you in a cone of GPS jamming silence.

　　Of course, terrorists fighting on the ground in Afghanistan and other countries also make use of GPS signal jammers, some Russian made.

　　However, just because you have a GPS signal jammer doesn’t mean you still can’t be tracked. The models intended for cars, for instance, only work while the car and thus the GPS jammers is powered on. And you can still be tracked by your mobile phone’s own signals if you don’t take precautions.

　　GPS and other Global Navigation Satellite Systems (GNSS) circle the earth in medium earth orbit, which is around 12,550 miles above the ground – the equivalent of almost five trips from San Francisco to New York. Since those satellite signals are transmitted across such a great distance, they are pretty weak by the time they actually reach your device.

　　In a GPS spoofing attack, a terrestrial radio transmitter mimics GPS signals at a greater signal strength than the actual system can muster, effectively replacing real GPS signals with a fake signal. This used to be complicated, expensive electronics that only militaries could do. Today, it’s almost ridiculously easy to gain access to such a transmitter. A GPS jammers is available on the internet for around USD 100.

　　One of the reasons that GPS is easy to spoof is that the signal is unencrypted. Since no form of authentication or verification is required for GPS transmissions, just about anyone can use the publicly available specifications and falsify a location.

　　Spoofing GPS is no longer something that requires the resources of a nation-state. GPS spoofing technology is virtually free, widely available, and very popular.

　　Many people produce a fake GPS location to prevent applications from precisely tracking their movements. Some do it to maintain control over their personal data by telling location services that are overtly or covertly tracking users that they’re in Kazakhstan. Teenagers use GPS spoofing to mask their location from prying parents. Others use GPS spoofing to perpetrate (or hide) fraudulent activity.

　　Spoofing your device’s GPS receiver so it displays another place is also a popular way to obtain access to country-specific features of games and other applications. Some rare wifi blocker can only be found in certain parts of the world – if you can’t travel to get them, placing your phone there virtually is the next best thing.

　　GPS jammers can also disrupt many communication systems, including the Tetra Airwave system used by emergency services. It transfers only one thousandth of the phone's charge. Jammers are readily available from Internet sources and cost only a few dozen pounds. Their impact on GPS-based security systems is severe.

　　They use them to disrupt tracking systems, thereby stealing vehicles and their valuable content. Jammer: A low-power radio transmitter that can overwhelm GPS reception at a range of tens of meters. This particular model also interferes with the mobile phone band. It blocks the data channel of any tracking system and disables mobile devices that can be used to call for assistance or track themselves using cell site analysis.

　　Nearby jammers can easily deafen a vehicle's sat navigator because it's hard for them to hear these tiny signals. GPS jammer technology is developing rapidly.

　　GPS, Galileo, Chinese, Japanese and Russian satellite navigation systems and their enhancements all use essentially the same technology and the same frequency bands. Therefore, switching from GPS to other GPS does not prevent interference.

　　If deployed correctly, it could affect the GPS of an entire city. This signal cellphone jammer would beat GPS-based road user pricing systems; and jammers ten times more powerful than those on the market today.

　　Even more serious than jammers are civilian GPS spoofers, which have been shown recently. Spoofing is sending fake GPS signals; the receiver locks on to them, and the spoofer takes control of the receiver. Fraudsters will allow criminals to hijack and divert the vehicle, while the tracking system shows it's still following its planned route, so no alarms will sound. Vehicles will also be able to avoid a purely GNSS-based road user pricing system.

　　There is no evidence yet that criminals have access to cheaters. But there are already low-cost GPS generators with programmable scenarios that can use Google Earth to input trajectories. So deception is not far off.

　　What are the options for mitigating interference and deception? Improve its technology to detect jammers and try to legally ban their sale and use. Of course, all radio systems are interferable - it's a matter of degree. But these two are harder to jam than GPS and don't draw people's attention.

　　The most infamous GPS jamming event in history of GPS has to be the San Diego Airport disruption. A Single event brought the flight control room in the San Diego airport to its feet, wondering and panicking to as to what was really going on. ATM machines refused customers , the Harbor traffic management system was going haywire. All this because of a GPS jamming event. A clear indication that the GPS system does not just run your Sat Nav on the car, it does a lot more than that.

　　GPS is in a sense, is a silent force that powers the modern communication world. mobile signal jammer network service providers use GPS time signals to coordinate how your phone talks to the cell phone towers. Electricity grids turn to GPS for synchronization when they are connected together. Banks and stock exchanges use the GPS/GNSS for time-stamping transactions without which commerce would be rendered impossible.

　　The GPS Jamming was eventually identified after 3 days of investigation – a navy exercise to test procedures when communication was down. The had also jammed GPS signals unintentionally. Unfortunately, the jamming expertise was not just localized or available to the Navy or the Military. There was another infamous event where a truck driver was using a GPS jammers near an airport to avoid being tracked! The GPS jamming device is available for under 30$ online but it’s illegal to use/buy such a device only in a few countries. Many across the world have not yet realized the danger and disruptions that these devices can cause.

　　So isn’t there anything that can be done to find the Jammers?

　　Actually, until now it was possible to find the presence of a GPS jammer but was not possible to locate it.

　　In 2013, the Federal Communications Commission fined a person almost $32k for using a device intended to evade the fleet management tracking system on his company vehicle. The device in question: a jammer gps.

　　Eventually, with help from the FCC and with specialized equipment, they were finally able to identify the cause of these inexplicable problems: A contractor on site was using a GPS jammer that not only blocked his company vehicle’s fleet tracking system, it also took down the GBAS in the process.

　　GPS jammers are usually small devices that plug into a vehicle’s lighter port and emit radio signals that overpower or drown out much weaker signals such as GPS or others. Although GPS jammers are illegal in the US, they are easily available online and are becoming more and more common as the use of fleet management tracking systems increases. These devices may seem relatively harmless at first glance, but their potential to cause harm is significant.

　　The case of the jammer at the Newark Airport is a perfect example. A simple $30 device was able to take down a state-of-the-art, highly sophisticated landing system at one of the busiest airports in the world. Worse, the device user wasn’t even trying to do so. Imagine what a person who DID intend to do harm could do?

　　In timing applications,portable jammer can disrupt the GPS signal, causing the underlying systems to lose their ability to synchronize their internal clocks and, in turn, their ability to stay in sync with the rest of the network. Since many critical infrastructures sectors require synchronization across their network to be within millionths of a second, even short-term GPS outages can have a major impact. Worse, when an outage occurs, there’s typically nothing to indicate that it’s a result of jamming. The GPS signal simply is not received anymore.

　　To make matters even more dire, many of the datacenters that house the servers these networks run on are in warehousing districts (with trucks coming and going frequently) or near major highways. These are two of the most likely places to encounter GPS jammers. In fact, at Orolia we know from experience and real-life examples that it not only happens … it’s relatively common.