The question is not whether Britain could afford its own GNSS – at a cost of around 20 billion pounds over 20 years, it clearly could – but if it should.
Depending on one’s perspective, this is either a vanity project, or strategic insurance against the western alliance possibly disintegrating at some point.
I leave the discussion of whether it is wise to base the launch site in Scotland, which may very well become a separate country in these years, to the political thread.
or strategic insurance against the western alliance possibly disintegrating at some point.
This is the bit I don’t get – whether in relation to the topic (Galileo) or any other GPS system. As I wrote above, and I believe this is a commonly held view among the powers to be, all GPS signals will be turned off or jammed if there is a major conflict. So having your own system will be totally worthless. The encrypted signal can be jammed just as easily…
And it always was totally worthless. Well, certainly post-2002 it was; this is when the US turned off Selective Availability supposedly permanently, enabling GPS to work properly for satnav and all the other economically crucial applications. Before 2002, it was a legitimate proposition for some country (or the EU, in the case of Galileo) to have its own system which doesn’t have SA. Well, that was 17 years ago… Today, turning SA back on would cripple the US economically and this is why the US cannot mess with it. They could deny the signal to countries well outside the US (not hard since the US is surrounded by a lot of water to the east and the west) but that would harm their economic interests enormously. So I cannot see a peacetime scenario where this issue could happen.
At any point post-2002, Galileo was a pure vanity project. And so would a UK replica. Practically nothing uses the Galileo signal today and absolutely nothing would use the “UK-GPS” signal
That is why I wrote “depending on one’s perspective”. My perspective is also that this is a vanity project.
But the case for the other side is not quite as silly as one might think, once you look at a time frame of decades.
One way to deny “others” access to a GPS is the encryption of signals and information. So for example, the US could simply encrypt the navigation message on the signal, and make the decryption keys available to commercial users in “friendly” countries while controlling exports. With GPS receivers having a lifespan measured in years (outside aviation) this can take place over maybe 5 years, and you have transitioned the existing open GPS system to a closed one. Civilians in the US, the US merchant navy and their global military operations would still have access to GPS, nobody else would.
Practically, this may require updated satellites if hardware changes are required, so might take a generation refresh in the satellites.
As I said above – I consider this highly unlikely, and with other systems around (four and growing) I can’t really see the case for spending 10 billion to build one and another 0.5 per year afterwards to keep it going…