Multi-GNSS method for measuring traceability in GNSS receivers

摘要

Determining the traceability or accuracy of Global Navigational Satellite System (GNSS) by receiving a first signal from a first GNSS 203, a second signal from a second GNSS 209. A first and second value is calculated in dependence on data in the first and second signals respectively. One or more of an average and a measure of traceability is then determined based on the first and second values. The first and second values are preferably location values and the average is calculated as a mean or median of the first and second values. Preferably an alert is issued if the traceability exceeds a traceability threshold which is determined based on a long term average of a measure of traceability.