There is absolutely no way that we can be spoofed or jammed without our knowledge. We will immediately recognize them and take corrective action.
These are ways that we defend against jammers and spoofers and inform users of details.
We have a very powerful spectrum analyzer within
our GNSS TRIUMPH chip. Each spectrum shows
the power and the shape of the interfering signals
and jammers. This is more powerful and more efficient
than having a $30,000 commercial spectrum
analyzer to evaluate the environment. The screenshot
on the right shows the shape of the GPS L1
band spectrum when the band is not jammed. The
GPS C/A code peak at the 2-MHz center of the L1
band is visible.
This is an example of GPS L1 spectrum with a commercial $30,000 spectrum analyzer.
Our integrated spectrum analyzer has the advantage that it monitors the spectrum inside the chip where it matters. It has effective bandwidth of 1 KHz.
Our embedded spectrum analyzer also has the advantage that it can be programmed to automatically record the spectrum (and other information) periodically or according to the set conditions, and monitor the environment continuously.
This is the spectrum example of a GPS L1 band when it is jammed. There is a huge peak in the center where the C/A code is. The number on the bottom left is the height of the peak.
The height of the spectrum is 21.1 dB, which compared to the calm 11.2 dB, indicates about 10dB of jammer.
Although we label the bands as three GPS and 3 GLONASS bands, but they represent all bands of all GNSS signals, because bands are shared by all GNSS signals.
Spoofers & 2 Peaks
Spoofers are quite different from jammers. They don’t disturb the environment and the spectrum shape. They broadcast a GNSS-like signal to fool the GNSS receivers to calculate wrong positions.
In the top screenshot 10 GPS satellites were visible (according to the Almanac). 6 of the 9 GPS satellites that we tracked were spoofed, as indicated by the red number, while the noise level was 0% in the GPS C/A band.
In the second screenshot, 5 of the 6 GPS C/A signals were spoofed while the noise in the band was only 2%.
We detect spoofers by digital signal processing. With 864 channels and about 130,000 Quick Acquisition Channels in our TRIUMPH chip, we have resources to assign more than one channel to each satellite to find ALL signals that are transmitted with that GNSS PRN code.
If we detect more than one reasonable and consistent correlation peak for any PRN code, we know that we are being spoofed and can identify the spoofer signals. Figure on the right is an example of two peaks. We isolate and ignore the wrong peak.
The screenshot on the right shows details of each signal. The first six lines in this screenshot show the spoofed signals that we detected as soon as they appeared (numbers “1” in those line). The two section columns represents the characteristics of each peak. Second SS column show if the second peak is a consistent signal.
While six satellites were spoofed, there was no indication on the noise level (0%) and no indication on the spectrum shape and level as shown on the screenshot on the right below the chart.
If the spoofer strategy is to cover the real satellite signal and then put the fake signal on top of it to produce only one peak, we notice that by more that 200% of noise level that it has to introduce.
We reject infected signals and then among all the available GPS, GLONASS, Galileo, BeiDou, IRNSS and QZSS multiple signals we use the healthy ones.
Usually there are over 100 signals available at any given time, and we need only four good signals to compute position. In rare cases that all signals are affected, we inform the user and guide them to use compass and altimeter to get out of the Jammed area.
There is absolutely no way that we can be spoofed without our knowledge. We will immediately recognize and take corrective action.
And Examples of when the world is peaceful.
Jamming and Spoofing protection option is available in all of our products and OEM Boards.
All screenshots are from our
When you detect that spoofers exist, you can also try to find the direction that the spoofing signals are coming from. For this, hold your receiver antenna (e.g. TRIUMPH-LS) horizontally and rotate it slowly (one rotation about 30 seconds) as shown in the picture and find the direction that the satellite energies become minimum. This is the orientation that the spoofer is behind the null point of the antenna reception pattern.
After one or more full rotations observe the resulting graph that shows approximate orientation of the spoofer as shown in figure below.