IonoGuard Now Available In Trimble Can-Net

Trimble Positioning Services has announced that Trimble IonoGuard is now available in all CMRx mountpoints in the Trimble Can-Net Service. Trimble IonoGuard technology, introduced in late 2023, is designed to mitigate the effects of ionospheric disturbances and scintillation, enabling reliable RTK initialization. With IonoGuard enabled in the network, ionospheric information for each satellite is now being transmitted via CMRx MSM protocols to rover receivers. IonoGuard rover receivers utilize this information, together with their own ionospheric measurements, to optimize the computed positions and initialization times.

IonoGuard Receiver Configurations

There are three InonoGuard modes available for Integrated Survey Receivers:

• Disabled - The receiver will not do any IonoGuard processing.
• Enabled without Fallback Mode – If a rover is connected to Trimble Can-Net CMRx mountpoints, the network stations perform ionospheric disturbance detection, and the ionospheric information is then sent to the rover receiver via the CMRx MSM protocol. IonoGuard rover receivers utilize this information, along with their own ionospheric measurements, to optimize the computed positions.

  If the user is receiving RTCM messages, then IonoGuard is disabled, and the receiver will not do any IonoGuard processing.

• Enabled with Fallback Mode – If a rover is connected to Trimble Can-Net CMRx mountpoints, the network stations perform ionospheric disturbance detection, and the disturbance information is then sent to the rover receiver via the CMRx MSM protocol. IonoGuard rover receivers utilize this information, along with their own ionospheric measurements, to optimize the computed positions.

If the user is receiving RTCM messages, then no IonoGuard information is being passed from the network to the receiver. However, the receiver will perform independent Ionospheric processing and use these adjustments to improve its positioning performance.

Recommended Receiver Firmware Versions

To maximize the benefits of Trimble IonoGuard within Trimble Can-Net, it is important to keep your firmware current. Data gathered during significant ionospheric events over the past year have been analyzed, enabling ongoing enhancements to the IonoGuard solution for rover positioning and improving its ability to mitigate future disruptions.

Firmware version 6.40 significantly enhances rover positioning when using Trimble Can-Net corrections. Specifically, it enhances the scaling of ionospheric gradient data when IonoGuard information is transmitted to the rover via the methods listed above. This enhancement is designed to boost rover performance, particularly during periods of substantial ionospheric activity.

Tools Available Regarding Ionospheric Activity

Tools like GNSS Planning online can help you identify periods of high solar activity and atmospheric impact. Below is a plot demonstrating the past TEC, scintillation, and Ionospheric index values over a given time period. This tool enables you to view historical ionospheric conditions for a specific set of coordinates.

This article is based on the original Trimble bulletin published in May 2025.

Additional resources on Solar Cycle 25:

• Trimble Positioning Services (English only)
• Cansel advisory – On Point Newsletter April 2025 edition
• Contact Cansel for firmware update inquiries

© 2025, Trimble Inc. All rights reserved. Trimble and the Globe & Triangle logo are trademarks of Trimble Inc., registered in the United States and in other countries. All other trademarks are the property of their respective owners.