A couple of months ago I shared an article with an admonition from Brad Parkinson, GPS founding architect, that measures need to be taken to ensure the resilience and robustness of current GNSS systems. One method of doing so is to augment signals with data from other sources just in case a satellite failure were to occur. Now here we are only two months later, discussing not one, but two recent failures of the GLONASS system, the first of which rendered the entire constellation completely unusable for about 11 hours. This GPS World article provides more details about that system failure.
Now that we have seen very real confirmation that redundant systems are justified, more focus can be given to various augmentation systems, such as the Ground Based Augmentation System (GBAS) noted by Richard Langley in this article.
This image shows the basic operating principle of ground-based augmentation, providing a redundant source of positioning data to receivers.
In a third article, the CEO of Locata Corporation, Nunzio Gambale, stated “We have been telling the industry for years that you cannot have a critically important capability like GPS without also having a backup! What is Plan B if the satellite systems fail? What replaces the space signal when there is a problem?" Locata offers terrestrial position technologies that complement GPS, with their equipment currently operating in environments such as small warehouses and open-cut mines, and in wider areas for the use of aircraft and UAVs.