About GNSS and GPS

This blog post covers the GPS jammer. See the message listed below for a description of GNSS spoofing.

Prior to a time server sends out messages including time information, it generally receives this information from a GNSS receiver This is a worldwide navigation satellite system. These systems include the Gps (GPS), Galileo, GLONASS and also BeiDou.

These systems all have something in common. They rely on obtaining low-power radio frequency (RF) signals from satellites in the L-band in between one and two GHz. The signals are power efficient due to the fact that they are sent from satellites with minimal offered power as well as the satellites are far away. General practitioner transmits its L1 signal at 14.4 dBW. Nevertheless, by the time you get it, it's -157 dBW since the satellites are 20200 km away. It resembles grabbing the signal from your youngster's baby monitor from the following town. That simply mosts likely to reveal what technical wonders GNSS receivers are. In spite of the brains of GNSS receiver styles, they are really vulnerable to RF disturbance.

GNSS disturbance comes in three selections: unexpected disturbance, deliberate interference (jamming), and also spoofing. Unintentional disturbance can originate from a nearby antenna transferring in a surrounding frequency band that is dripping right into the GNSS regularity because of a wandering oscillator or an imperfect bandpass filter at the transmitter. Usually, you can stay clear of unintentional interference with a timing receiver by making certain the antenna is far enough far from other antennas. And since timing receivers don't normally move, get it right when you install it as well as you're normally good for the life of the item. Exactly how much does your GNSS antenna require to be from one more antenna? If the various other antenna is designed to get, i.e. not purposefully send RF signals, 3 meters is possibly adequate. If the other antenna is transmitting RF, it depends on the signal stamina. Simply place it as far as you can.

Deliberate disturbance is described as interruption. Why do people jam GNSS? This can take place when someone runs a GNSS jammer. wait what Why would anybody do that? The most common factor is to avoid a vehicle from being tracked by its navigation system. Plug a GNSS jammer right into the cigarette lighter socket as shown in Figure 1 and also you will protect against the auto navigation system from obtaining GNSS signals. They likewise avoid a receiver from working within a block distance, consisting of perhaps your timing receiver. These tools are commonly used by expert motorists that sometimes do not desire their activities to be tracked by their company or by cars and truck and truck thieves.

General signal jammer with cigarette lighter. Can be bought online for $150.

Just how common is this problem? The European Company for Worldwide Navigating Satellite Solution has actually launched a task Strike3 in which L1-band interference surveillance systems have been deployed in 23 nations. They logged 450,000 disturbance occasions over a two-year period. Of these, 73,000 had a considerable influence on GNSS operation. A lot of the impactful events, 66,000, came from jammers. Oops!

What are you doing regarding it? One thing you can do is acquire an excellent oscillator with your time server. Most events are temporary. Usually, the auto jammers lie in lorries that are driving by. I hope your automobile does not obtain taken!

GNSS disturbance events logged by the European Navigating Satellite System Strike3 project.

To obtain a feel for which oscillator you require, you can look at the holdover functions of different oscillators in.

Holdover for various oscillators at constant temperature as a function of desired accuracy.

But you can do something else. If your time server has 2 GNSS receivers with antennas far sufficient apart, it is unusual for both antennas to be obstructed at the same time. Exactly how do you obtain sufficient antenna splitting up? One means is to downconvert sending over a fiber optic cable.

Fiber optic cable connection for a GPS receiver.

Lastly, some antenna makers develop antennas that block low-angle signals coming from near the ground. Most of the moment interference signals come from this direction.