Maintenance

Keeping the system up-to-date is crucial in most applications requiring high reliability. The following suggestions can help you prevent many potential issues:

  • Establish how the system is normally working (for easier anomaly detection) 
  • Maintain the hardware regularly (check connections, wires)
  • Maintain the software regularly (firmware updates, software updates)
 
Hardware
 
Antennas are often exposed to the elements; wires can get bent or broken and the receiver may experience power surges or may be accidentally mishandled. GNSS signals are incredibly weak by design, so a simple broken (or incorrectly connected) cable can lead to such a decrease in signal strength that the position may not be (correctly) computed. If an application relies on a single receiver, such a defective cable can lead to a chain of issues that can be prevented by doing regular maintenance. 
Some actions you can take to understand the status of your hardware, and to make sure it’s in good working condition: 
  • Establish normal behaviour (to better detect deviations)
  • Check power supply to active antenna LNA (low noise amplifier)
  • Check coax cable quality
  • Check power supply to receiver
  • Check data cable to receiver
 
Software
 
The software side of a PNT system is as important as the hardware: one broken connection or bad setting can lead to a processing error, that can lead to erroneous PNT data. The parts of the system you need to check are the connections to and from the software, the compatibility of the system with the format in which the information arrives, the ability of the system to handle said format with appropriate speed, and the intended functionality of the processing algorithms. If there is data storage in the loop, you must also check whether there is sufficient storage capacity and whether the data is properly backed up. 
There are many software blocks present in a PNT system; some of the examples you can see on the figure below:
 

Global Navigation Satellite Systems are subject to developments that widen their applications and increase their robustness and accuracy. As part of these developments new signals and message types are being introduced. The user side of GNSS has to be kept up-to-date with new developments. Therefore it is important that the software (and firmware) is regularly updated and is ready to handle the newest features, such as the authentication of signals (OSNMA) which in itself adds another layer of reliability to a PNT system.

Some actions you may take to ensure your system is properly maintained: 

  • Check for software updates regularly
  • Update firmware (for instance of the receiver)
  • When updating the receiver’s firmware/software:
    • Check if the script controlling it needs to be changed or if it’s still functioning properly
    •  Check for features that are no longer supported (legacy), and make sure your system doesn’t rely on these (any more)
  • Check for updates in the receiver’s settings/configuration
  • If there are added features (like OSNMA), check if it’s available and enabled in your receiver’s configuration