Calibration of GNSS Signal Power

Calibration of Signal Power, and their utilisation from ground tracking network for constellation monitoring

The Challenge

Global Navigation Satellite System (GNSS) signal structure and signal power can undergo changes due to planned modifications to improve or enhance the service being provided, maintenance changes which have affected the performance of the satellite, deliberate reshaping of the signal structure over geographical regions, or degradation of satellite performance due to age. Any changes to the signal structure and signal power are of interest to systems that rely on it for safety critical applications, and for those that are interested in the highest precision. This project aimed to obtain a baseline set of observations of the signal structure and power being transmitted by navigation satellites over Australia to develop monitoring capability. It also established whether there is a requirement for an ongoing monitoring program using a high gain antenna (used to increase signal strength).

Partners

The project partner is Geoscience Australia.

The Solution

This project is a sub project of the On-going Development of the Multi-GNSS Analysis Centre Software (ACS). It aimed to research, develop, and implement ACS prototype modules that:

  1. Allow the processing of carrier-to-noise values typically ignored in GNSS processing.
  2. Obtain a baseline set of observations of the signal structure and power output by GNSS operating over Australia.
  3. Use these values to improve orbit modelling and assist calibration of the processing software.

In summary, the project involved:

  • The determination of the total signal power being transmitted by GNSS using a high gain antenna.
  • Obtaining updated antenna thrust values for orbit modelling repeat observations after six months to verify the initial findings.
  • Developing a carrier-to-noise process application based on the ACS software that can be used to monitor the total signal power being transmitted by navigation satellites and can be used to monitor their performance. It will also determine whether past events can be detected from archived data that has been obtained from the ground tracking network.
  • Extending the ACS software package to include absolute antenna calibration values. The project will seek to establish if a near-real time system can be implemented to detect changes in signal structure/power from the ground tracking network.
Impact

Position allows us to locate ourselves in the world and get to where we want to go. This brings increased productivity, improved community safety and boosted innovation. The reported economic benefits of positioning technologies have the potential to generate upward of $73 billion of value to Australia by 2030. This project will develop the capability to monitor the total signal power being transmitted by navigation satellites over Australia which can then be used to monitor their performance. This will mitigate the negative impact that change in signal structure may have upon different navigation users, from safety of life, precise geodetic users through to single frequency mobile device users. The results of this project will be incorporated into the ACS software and made available via an open-source licence. The project outputs will also have applicability beyond Australia’s borders.

Contact

Please contact us at contact@frontiersi.com.au for more information.