Quality Monitoring of Real-Time Precise Satellite Orbit and Clock Corrections for Generating Health Indicators

The Global Navigation Satellite System (GNSS) Precise Point Positioning (PPP) service provides real-time high precision positioning worldwide. It is essential to monitor precise satellite orbit and clock product quality for early alerts to GNSS users. This paper introduces a server-side method to g...

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Bibliographic Details
Main Authors: Xie, Mingqiang, Liu, A., Wang, N., El-mowafy, Ahmed, Wang, Z., Wei, D.
Format: Journal Article
Published: Elsevier 2025
Online Access:http://hdl.handle.net/20.500.11937/96941
Description
Summary:The Global Navigation Satellite System (GNSS) Precise Point Positioning (PPP) service provides real-time high precision positioning worldwide. It is essential to monitor precise satellite orbit and clock product quality for early alerts to GNSS users. This paper introduces a server-side method to generate Health Indicators (HI) for satellite corrections. Phase residuals from historical data are modeled as a Residual Hemisphere Map (RHM) to establish monitoring thresholds based on satellite elevation and azimuth. A satellite subset separation scheme is used to identify all faulty satellites by comparing real-time phase residuals with the corresponding thresholds. Tests using data from 30 IGS stations show that the RHM-derived thresholds effectively bound residuals under fault-free conditions. Moreover, the method detects single satellite faults over 5 cm immediately and ramp errors of 1 cm/epoch within 5 epochs, as well as multiple simultaneous faults. The HI generated can be broadcast to users for excluding faulty satellites.