Solar Activity & (RTK)GNSS Impact
What is Increased Solar Activity?
The sun, which causes this disturbance, goes through a cycle that takes about 11 years on average. During this period, the Sun's magnetic activity gradually increases to a peak and then decreases again. During a period of increased activity, where the sun is currently moving towards, all signals traveling through space may be affected by this activity. The signals that travel through space are then disrupted by magnetic force caused by explosions on the sun. The disturbances of these signals, such as the GPS signal that reaches your phone, iPad, UNI-GR1 or any other GPS receiver can be affected by this.
Solar activity is currently increasing and will peak around 2024. Then it is expected that the most explosions will take place on the sun and with that more space storms will be associated, which will therefore cause the disruption. Incidentally, the previous expectation was that the peak would take place in 2025, these expectations have recently been adjusted and it seems that the peak is getting closer. For more information about this cycle as well as the phenomenon, I would like to refer you to this US government site and this article. And besides GPS, other systems can also be affected by this phenomenon, as was the case during a power outage in Canada.
What are the consequences for GPS users?
Due to the disruption of the GNSS (GPS) signals during a "solar storm", all devices using these signals become less accurate. In the case of your telephone or navigation system (single frequency receivers) this means a reduction in accuracy from a few meters to tens of meters or more. In the case of centimeter-accurate equipment such as the UNI-GR1 or other dual-frequency RTK GNSS receivers, the result is that the receiver cannot always "lock" properly to the satellites, this results in the usually known centimeter-accurate FIX not getting better than a "FLOAT" value with 10 to 30 cm deviation.
When will I experience these consequences and how long will this last?
Unfortunately, this is very difficult to predict. As the US government's model shows, we expected the next effects later. For example, the actual solar activity in December was about 1.5 times higher than the predicted value. For January this number is not yet known, but based on the day-to-day values on the Swiss government site, it seems that January is once again higher than predicted. Fortunately, what you can also see on this site is that the increased solar activity does not take place every day or all day.
This increased solar activity has the most effect in our northern hemisphere in the winter months and especially in the middle of the day. So if the increased solar activity has an influence on obtaining a FIX, it will mainly be around these times.
What can we do about it?
Unfortunately, there is nothing we can do about this increased solar activity itself. We can, however, inform you as well as possible, for example through this article, but also through optimisations, so that the impact for you is as minimal as possible.
For example, almost all RTK network suppliers, including the team behind UNI-RTK Premium, are doing everything they can to map this solar activity as accurately as possible and to model it. In this way they try to ensure that the correction data is affected as little as possible by this solar activity, or even corrects for the solar activity. This is an ongoing process, but unfortunately this process always lags behind the facts, as they have to follow solar activity and cannot predict it.
What can you do to keep measuring easily?
I can imagine that it will only bring you frustration, after all, you just want to measure with GPS. Fortunately, this is also possible and many of our users have been able to measure well in recent days, by using the following tips;
- The increased solar activity mainly takes place between 11am and 3pm, try to plan your work before or after this time.
- You can track the current solar activity, among others via websites like this one and this one.
- If possible, start up the GNSS receiver in conditions with few buildings or trees.
- After obtaining a FIX, allow your receiver at least a minute or more to prevent it from losing the FIX after movement. This gives the receiver time to "lock" properly.
If you find it interesting, you can find more information about the phenomenon on the following websites;
https://www.swpc.noaa.gov/products/solar-cycle-progression
https://www.swpc.noaa.gov/impacts/space-weather-and-gps-systems
https://www.swpc.noaa.gov/phenomena/ionospheric-scintillation