| Solar Cycle 25 | We are approaching the peak years of the latest solar cycle (the 25th since the phenomenon was tracked), which will peak in 2025.
During this period, space weather events like solar flares and coronal mass ejections (CME) will occur. During such events that can last one or more days, you may experience long fix times, inability to fix, or high residuals.
Note that such events are not frequent; we’ve only had a handful over the past 20 years. However, if you are experiencing such field difficulties, space weather could be a contributing factor.
Read more about this on our space weather page, which can be found here: https://c4g.lsu.edu/index.php/rtn/space-weather-gps.
We have added links to our http://C4Gnet.XYZ website that allow you to see the locally derived ionosphere Index (I95) and the predicted ionospheric/geometric errors, which indicate the estimated impact you could expect in a rover measurement. The I95 represents current conditions. If you see the index in the red for one or more hours, you might experience the effects noted above.
Here is a link to the NOAA Space Weather Prediction 3-day Forecast: https://www.swpc.noaa.gov/products/3-day-forecast
The forecast is expressed as Kp Index. If you see a Kp of 6+, then you might experience the effects noted above. By looking at current Kp values, and the locally derived I95, you can get a sense of what to expect. | 1/8/2025 | 5/17/2026 | Warning |
| NGS Updating Coordinates and Velocities | On June 11th, NOAA’s National Geodetic Survey (NGS) will be updating its OPUS products to work in the new International Terrestrial Reference Frame of 2020 (ITRF2020). Implementation will also result in updated NAD 83 control coordinates for all CORS. The Multi-Year CORS Solution 3 (MYCS3) results will be used to implement new coordinates and velocities in the latest global reference frame (ITRF2020) for stations in the NOAA CORS Network. This will also result in updated NAD 83 coordinates for stations in the NOAA CORS Network (NCN), kept at NAD 83 epoch 2010.0.
Due to these changes, C4Gnet.XYZ will be updating its NCN CORS to agree with the new NGS publications. While we don't anticipate these coordinate changes to be very large, we will need to apply them to the C4Gnet.XYZ Real-Time network to keep it constrained to the National Spatial Reference System. This will ensure that the positions you get from our C4Gnet.XYZ RTN are consistent with the solutions provided in NGS's OPUS products.
We anticipate these changes to take effect on June 11th, 2025 unless NGS delays its publication of the new coordinates and velocities. | 6/6/2025 | 7/31/2025 | Alert |