Galileo

[andygates]

ESA's Galileo positioning sats are getting ready for launch: BBC NEWS | Science & Environment | Galileo 'pathfinders' take shape

Just the test constellation for now, but it's all progress. 

Question is, will current GPS units be able to use Galileo too (presumably with a firmware update) or are they different enough to require new recievers?

[Panoramix]

The answer is may be.... BBC NEWS | Science/Nature | Q&A: Europe's Galileo project

But apparently future receivers will be able to use both signals.

[TimO]

One of the Galileo Open Service (OS) frequencies is quite close to the GPS Coarse/Acquisition (C/A) frequency.  They are both around 1.5GHz.  OS also has a second frequency, which like the two frequencies used for the GPS Precision (P(Y)) mode allows greater accuracy.

I would imagine that this means that with a suitable software upload (and assuming the modulation scheme is similar), a current GPS receiver could work with the Galileo OS mode, but not at the greatest accuracy it's capable of.  You would need a receiver which also operated around 1.2GHz to achieve that.

Having said that, by combining fixes from both GPS and Galileo, you should be able to increase your accuracy to above that provided by each individual system in isolation.

[andygates]

Having said that, by combining fixes from both GPS and Galileo, you should be able to increase your accuracy to above that provided by each individual system in isolation.

Bing! Give the man a cigar.