On 2 April the Russian satnav network, known as GLONASS, suffered ‘major disruption’ when all 24 satellites produced corrupted information for almost 12 hours. It took almost 13 hours to fix and during that time GLONASS was giving location data up to 55 kilometers out off the UK coast, according to the General Lighthouse Authorities. Pretty scary if you were relying on it!
This ‘outage’ is discussed in a fascinating new issue of Navigation News (from the Royal Institute of Navigation www.rin.org.uk). It starkly reminds us of the urgent need for a robust back-up to existing global satellite navigation systems (GNSS), including GPS.
It’s not yet clear exactly what went wrong with GLONASS but there’s no reason to suppose that GPS or any of the other GNSS now in the pipeline – including the EU’s Galileo – is any less vulnerable.
Professor Chris Rizos of the University of New South Wales commented: ‘This catastrophic failure of one of the world’s two global satellite navigation constellations is a wake-up call for all of us. We ignore the possibility of these events at our own peril’.
It would be nice to think that the good old sextant might fill the gap but of course GNSS does far more than just give a positional fix. It also provides a super-accurate time signature on which many non-navigational systems now rely – including the world’s financial markets and mobile phone networks. So there’s a great deal more at stake here than shipwreck or taking a wrong turning.
The best potential back-up in the event of GNSS melt-down is eLORAN – ‘enhanced’ LORAN – a very accurate and relatively low-cost system. It relies on powerful low-frequency radio transmissions from land-based sites that are much less vulnerable than the extremely feeble ones from satellites. eLORAN doesn’t offer all the facilities of GPS but it is complementary and independent. Several countries are developing eLORAN in order to provide ‘resiliency’ in the event of GPS failures – including the UK and Ireland. South Korea too is on the case – as well it might be given that the North Koreans have apparently already been jamming GPS transmissions on their borders. But the EU apparently still behaves as if there’s no problem – and there’s little or no informed public debate on the topic.
That’s the most alarming thing of all.