They're alive! Galileo sats 9 and 10 sending valid signals Two more satellites in Europe's Galileo satellite navigation swarm are up and running, so to speak. The European Space Agency (ESA) has announced that the ninth and tenth satellites in the planned 30-bird fleet started sending “valid navigation signals” as of January 29th. Galileo's eleventh and twelfth satellites are also …
This is good. Do we want Sat nav that depends on good will of Russian and American presidents/military? (Putin & Trump or Clinton? Or maybe even Palin in 5 years! Well, probably not Palin or Trump).
I think cruise missiles (Russian or USA) can use inertial navigation and maps, as can ICBMs. I think a cruise missile can carry a nuke?
Cruise missiles can carry nukes and use inertial navigation and maps, but GPS is much, much more accurate. Which is why it was developed.
If your cruise missile has to travel over land for some distance during the winter in regions like Siberia, (radar) maps won't work that well because snow and wind are constantly changeing the ground profile.
Early ICBMs had basically a hardcoded flight profile and had to be launched from a precise location to make that work. Easy on land, tricky from a submerged submarine.
One of the reasons for developing multi-megaton hydrogen bombs was the poor accuracy of ICBMs - if the bang is big enough, targeting doesn't have to be that neat.
One of the reasons for developing multi-megaton hydrogen bombs was the poor accuracy of ICBMs - if the bang is big enough, targeting doesn't have to be that neat.
I find the same tactic useful when breaking wind after a night of beer and pickled eggs.
The advantage of using satnav for nuclear missiles is that they all end up wedged under a low bridge in a small west country village, thus averting any risk of nuclear war.
"It can be jammed or spoofed, so perhaps now more use as a civilian tool?"
Sadly, that's actually why phones and the like are mostly not compatible with GPS and Galileo - the US military wanted to be able to jam Galileo without disrupting their own system, and they forced the EU to use a different frequency to make this possible. So now you need a different receiver for each system, which obviously adds to the cost and complexity. Dedicated satnav systems, emergency beacons, and similar may use multiple systems, but there's little justification for the extra cost for a phone.
the US military wanted to be able to jam Galileo without disrupting their own system, and they forced the EU to use a different frequency to make this possible.
Those idiots forgot that it also works the other way. By insisting GPS be on separate frequencies, it makes targeting an individual country's GPS easier. If Russia, for example, wanted to launch, they could jam the US/Galileo/etc. while leaving their own operational. It would be better if all used the same frequencies since you couldn't jam X without jamming your own.
So Galileo may be up and running in the next 50 years, but by that time the first satellites will be out dated and nearing the end of their time. i will be dead by the time this system is launched and thenh the new devices have to be set up to deal with it.
Not that I use GPS, the GPS on my phone is disabled..
Gallileo supposedly uses a format compatible with NavStar.
Your old phone/GPS probably won't work with Glonass or Beidou(Compass) and almost certainly won't work with IRNSS, QZSS, the upcoming French system(*) or any of the augmentation systems using ground-based repeaters.
(*) Yes, the french are insisting on having their own independent GPS system, in addition to having fingers in the Gallileo pie.
Wasn't there a report a couple of days ago about UK DAB radio transmitters going a little haywire because. The USA decommissioned one of their GPS satellites which casued a minor loss of sync between the rest of the constellation.
Maybe no bad thing that there is a bit of redundancy in such a vital resource.
But do we care about DAB? A system that increases Listener power consumption by x5 to x20 compared to FM, less than FM quality and can even be worse distortion than a good AM signal. Needs 700 fill in transmitters in UK to give FM coverage too.
DAB also for local / community radio is more expensive and gives too much coverage. Local stations can't use a SFN mux either.
Some DTT SFN and Mobile bases may also stupidly use GPS to save a bit of money (£8000) at install time years ago (yes it's about £1100 now but was more then).
Sadly, as far as I can see, modern portable radios have now started using DSP chips to receive FM with a corresponding increase in power consumption. Not something that the manufacturers like to shout about. If you try to buy parts to build your own old-fashioned analogue FM receiver, the components seem to have disappeared from the supply chain.
I heard one apologist being interviewed trumpeting that 'modern radios use no more power for DAB reception than for FM' which whilst technically probably true, was highly deceptive in purpose.
A later story clarifies that GPS Time itself was slipped by 13 us due to some errors back at GPS HQ.
In that case, I withdraw my previous suggestion (just above). If the GPS Time signal is present, then it is not unreasonable to assume that it's 'the' standard.
Even if you had a local atomic clock for comparison, one would naturally assume that the local clock had gone haywire before you'd assume that the GPS Time had glitched.
The only exception would be if one had an array of atomic clocks (like at a National Lab); then one might be able to make the correction assumption.
"According to a leaked US Air Force document written in 2004 August and obtained by The Business, Peter Teets, under-secretary of the US Air Force wrote: "What will we do 10 years from now when American lives are put at risk because an adversary chooses to leverage the global positioning system of perhaps the Galileo constellation to attack American forces with precision?"
"The paper also reported a disagreement between EU and US officials this month over Galileo at a London conference which led to the threat to blow up the future satellites.
"The European delegates reportedly said they would not turn off or jam signals from their satellites, even if they were used in a war with the United States.
"They made it clear that they would attempt what they called reversible action, but, if necessary, they would use irreversible action," the official was quoted as saying. (AFP. 2004 October 24)
Ar*eholes!
Yesyesyesyesyes, evil American GPS blahblahblah.
But consider: Do you really want your car's positional information supplied in hogsheads per square newton or its speed quoted in millilitres?
I urge all European navigators to reject this so-called "Galileo" thingumy and use goodole-yankee feet'n'inches GPS.
The only proper dimensions to use are Planck dimensions since, with a few exceptions, they represent the extremes of what is measurable.
Planck Length = shortest length which has any meaning
Planck Time = shortest time period which has any meaning.
Plank Temperature = as hot as anything is ever likely to get
etc..etc
Of course, we'd have to get used to putting around 30 or 40 zeroes after everything, but at least it would get rid of the metric/imperial debate.
I'd love to go to my local builder's merchant and order a plank in Planck lengths.
Incidentally, the Plank energy (the energy content of a black hole that's one Planck length across) is roughly equal to ten gallons of petrol. I suppose that means my car has a "Planck tank".
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