Mastering the performance status of GNSS systems is of significant importance to GNSS end users, equipment manufacturers, and GNSS service providers alike.
(1) GNSS system suppliers are concerned with whether the signals and services provided by the system are available, reliable, and capable of delivering dependable services to users worldwide. A standardized method is therefore needed to continuously monitor and assess system signals and services.
During and after the deployment of GNSS constellations, it is necessary to continuously monitor the health status of GNSS satellites, received signals, and service capabilities. Through extensive and repeated monitoring, data processing and analysis, and performance assessment, it can be determined whether the system's actual performance meets its design requirements and is capable of providing users with usable, accurate, and reliable services. This is a matter of considerable importance to all GNSS service providers, including system owners, satellite developers, and operation and control managers.
Many performance parameters need to be monitored using observation sites located in different regions around the world in order to obtain data under a variety of geographical and environmental conditions. Comprehensive statistical analysis and assessment of this information provides a more complete understanding of system performance.
In the event of service interruptions, performance degradation, or other issues, GNSS system operators and managers need to promptly analyse and assess monitoring data, investigate faults or anomalies, and ensure the rapid restoration of services and the continued provision of reliable performance.
(2) Receiver developers are interested in whether GNSS systems possess the required service capabilities and service quality levels, as these factors influence decisions regarding which GNSS systems or signals should be supported by receiver products.
Differences in operating frequencies, information content, formats, solutions, and signal models across GNSS systems create new requirements for receiver antennas, boards, chips, software, and other components. As a result, the cost and complexity of GNSS receiver development have increased. Because it is often impractical for receiver manufacturers to support all signals from multiple systems, many choose selected multi-frequency signals from one or two systems.
When deciding which systems and frequencies to support, manufacturers need to consider factors such as service capability, service coverage, signal reception power levels, signal continuity, and service availability. These decisions are typically made following comprehensive technical evaluation, market analysis, and application studies.
Consequently, receiver manufacturers pay close attention to the service performance of different GNSS systems and require regular access to GNSS system performance assessments.
(3) Professional users and scientific research institutions are concerned with the service capabilities and performance levels of GNSS systems, particularly whether they can satisfy professional application requirements and scientific research needs.
Satellite navigation has been widely adopted across fields including national defence and security, the wider economy, and scientific and technological research. In critical application areas such as civil aviation, waterway transportation, highway traffic, geodesy, and time transfer, the availability, accuracy, and continuity of GNSS services are of particular importance. Any interruption in service can result in significant financial losses, operational disruption, or safety-related incidents.
In addition, providing ordinary users with information about GNSS system performance and service levels through publicly available channels can significantly increase confidence in the use of GNSS services. This, in turn, can encourage wider adoption, support the development of new applications, and stimulate further market demand.
Comment by: