Multiple systems are good
If they are all designed and implemented differently then the chance that they all go down at once is reduced. So in 2020, good Satnav systems will get four sets of data to compare and use as appropriate - cool.
Chinese officials have confirmed that the country’s Beidou satellite navigation system is operational, albeit mainly in China, and say they plan to have free, global coverage in place by 2020. At a press conference the China Aerospace Science and Technology Corporation said that Beidou – which translates as Big Dipper - is …
Multiple SVs from different contellations can even be used in a single positioning solution. You don't have to just compare the final positions.
Of course they all use RF in similar bands which means that they can all be nobbled simultaneously by solar flares etc,
Some, but not all, existing satnavs might be able to track these new SVs with just a firmware update.
Take two very nicely defined and clearly visible stars from the edge of the _BIG_ dipper, draw an imaginary line and the first bright star is Polaris.
The problem with finding the small dipper is that most of its stars are fairly non-descript and not particularly bright. So the method using an extension of the big is what they used to teach on survival (and civil defense) courses throughout the northern Hemisphere. At least outside UK. I remember having this explained to me in the 3rd or fourth grade and repeated several times later on.
So despite being unable to locate the small dipper (or most of the constellations) I can still find you Polaris straight away.
So the name is right - it should be the "Big" not the small dipper.
However it is missing things like the actual data format. However that specification already enables you to take a look at the signal.
As for more reliability, unfortunately I will have to put a damper on those hopes. It's in the same frequency range as GPS so penetration won't be better.
And Galileo, don't hold your breath, some people speculate that it only takes so long, so all the other players will build their own system therefore relieving Europe from having to make its own system.
It's hard enough to keep various systems synchconized as it is, let alone 3-4 "worldwide' GPS sattellite systems, each having various accuracies, software, firmware, manufacturer etc etc.
Let alone the comment that the Chinese would want "compatability" between the US and Chinese system and I have a concern as to "how compatable" these systems would (or should) be.
It seems to me that the Chinese know alltogether too much about how our military GPS system works and that they have shared that info with some of their friends in the Middle East.
I would prefer that there would be no comingling of GPS systems between Chinese and American systems since GPS obviously has so much military useage. Not to mention Iran's recent spoofing of GPS timing signals and resultant Drone capture.
Looks to me that it's time to brush up on our map and compass skills. Because you never know what "backdoor" is in that Chinese made GPS chip.
Compatibility in this case may be nothing more than making sure it doesn't hit the same frequencies at the same time as any of the other systems. It's of mutual benefit since the last thing ANY of the countries want (China included) is crosstalk messing up the signals.
Well, aren't you fashionably anti-America? See, what I don't get is why someone so convinced that we're a bunch of tools needs to resort to obvious untruths ('You have nothing anybody wants') to complete a good... to complete a flame.
We certainly have a lot of things nobody wants - Newt Gingrich comes immediately to mind - but having nothing anyone DOES want? The TCP/IP that helped Mr. Bailey's post across the pond to me suggests that even -he- wants something we -had-, at least. And I'm guessing that the CPU that's interpreting the flame was designed here, and that the TFT monitor was researched here, and that the plastic and velcro and gore-tex and nylon and etc, etc, etc.
The point here is not to brag (as I am not personally responsible for any of the above - including, thankfully, Mr. Gingrich) but to ask: Why? Why, if your position is so strong on me and my countrymen being utter twats, would your only argument be so bizarre? To quote Hudson Hornet from my son's regrettably-favorite movie, "I'm confused."
Hey David W., relax a bit, have another coffee, calm down. The simple statement that there is nothing in the good old US of A that is worth invading the country for seems plausible enough to me and not worth a rant. Similarly I don't suppose that there is anything sufficiently obnoxious to justify an invasion. Invasions are very costly and dangerous. Old fashioned diplomacy and commerce etc will (hopefully) suffice for the world's needs.
"And I'm guessing that the CPU that's interpreting the flame was designed here, and that the TFT monitor was researched here"
No, any significant research for the TFT I'm using done outside Japan was done in the UK. Granted the ASICs driving it would have most likely been designed using EDA software from an American firm, but then again the actual coding of that would likely have been done in a former Soviet nation or the near East.
HTH :-)
Amber waves of it! Vast waves of amber grain!
I mean, come on - Japan, Europe, even the Ukraine's grain! Is it as wavey? No! Is it as ambery? No! So yeah, don't even try to tell me people wouldn't want our amber waves of grain. It's even in some song.
...and that wasn't a troll. It was genuine frustration with the apparently ubiquitous, anti-US bias that seems to be a default position here. It's a bit like (Yes, these references are almost Godwin level now) the XKCD cartoon where a boy performing badly at math is told he's bad at math, while a girl performing badly at math results in the presumption that girls are bad at math. Except here, it's, if a eurozone bank fails due to greedy policy, it's due to its being a bad bank; if a US bank fails due to greedy policy, it's because America is full of greedy people and is unfair and everyone has guns and is fat and watches Fox news. I've seen it dozens of times, and that suggests two things:
1) Europeans have kneejerk prejudice about the US, just as the US has kneejerk prejudice about the EU. It seems to me that the vocal expression thereof (not just from this forum) skews more toward the former, and is more extreme; any remotely pro-US post or defense (however justified and calm) of the US seems to immediately attract thumbs-down approaching the dozen level.
2) I read the Reg too much.
I'm perfectly happy to slam the US where justified, but the automatic venom spat at the slightest mention of the United States is really quite off-putting - particularly when it's bald-facedly hypocritical (criticism of the US as being a jackbooted police state for putting up four traffic cameras in Montana, say, or on el Reg's part itself; mocking derision and anger when the US bans online gambling but not a whisper when the US un-bans it).
There, that's it, then. See, I even learned British speech patterns! I think I'll go have a nice lie-down; the excitement's made me head hurt.
Yes-maybe the Chinese authorities have traditionally made it look difficult to travel but I guess they are only trying to control things a little? For example - where do you think all the factory workers and city builders appear from? That's got me wondering on the average distance a worker moves from home?! Nice people the Chinese - friendly and polite)
Beidou is literally northern bucket.
The bei part means north.
The dou part is a bucket that can hold 20 kilos (usually of rice).
The northern bucket is the Chinese name for the Big Dipper (that points to Polaris, etc., etc.).
p.s. GLONASS is an acronym, that essentially means GLObal NAvigation Sputnik (satellite) System. GPS is acronym for Global Positioning System. The name Galileo is purely to honour the pioneering astronomer.
currently about 10 litres, it also is used to refer to objects shaped like a cup or a dipper, which is the usage at issue here, as can be seen by this explanation of the term on the Baidu website (http://baike.baidu.com/view/83954.htm) : “北斗”一词的本义是指北方夜空中接近北极点的一个星组,其形状如舀水的斗勺,故名。So rather than «northern bucket», a more correct (literal) rendering in English would be «northern dipper». Just goes to show....
In any event, kudos to the Chinese ! Why is it taking us so long here in Europe to get Galileo up and working ? Or don't we mind that much of our vital infrastructure is subject to the control of the Pentagon (and the people who control the Pentagon) ?...
Henri
Or are 10,000miles from it.
China's system is unique in that it uses geostationary satelites always in the same position above the equator. Apart from giving you very limited cover anywhere not on the equator, the accuracy and signal strength get very bad as you go north - it also means you can't tell if you are north or south of it from this system alone
The other problem is that if you want to invade or bomb somewhere you have to put a geostationary satelite over it first.
Most interesting thing is perhaps that it's not a "receive only" type system (sayeth wikipedia) but requires the ground set to send out a pulse to which the satellites that receive it reply. It might spell less need for spendy cesium clocks up there, but does have Chinese Implications. It also appears to enable "communication", maybe of a sms-type nature. Which is pretty useful, in a way. But giving your location away while trying to find out where you are may prove a bit of an unfortunate weakness.
Anyway, how long before we can have handsets that can use all four systems?
'..Most interesting thing is perhaps that it's not a "receive only" type system (sayeth wikipedia) but requires the ground set to send out a pulse to which the satellites that receive it reply..'
At Beidou satnav control HQ
Controller1 - 'ID:80dee2df79440e41a3c9f989a1b95821 has just been flagged, current location, at 23°59'26.15"N, 119°49'45.69"E.
Controller2 - "Naughty Boy...he shouldn't be there..dispatch the missile/interceptor/snatch squad"
This is pretty much GPS L1 (not surprising, DSSS is a good way to do it), at a slight frequency offset, at twice the chip rate (better code tracking precision, position/timing wise).
What surprises me is that there is no L2/L5 (in GPS terms) equivalent signal. Your everyday L1 receiver depends on a ionosphere model to compensate for the delay through the atmosphere. In GPS, L2 allows the delay to be measured, resulting in great precision enhancement. The reason your everyday receiver doesn't do L2 is it is military-only and encrypted. Thus, the latest GPS sats have L5, which is the same thing, just not encrypted.
I'm confused.
.......................squabbling over funding methods and cost overruns."
It also has to be mentioned that, initially at least, the US did a lot of heavy lobbying against Galileo in an effort to get the project dropped. They were not happy with Europe having a nav system independent of the US and gps.
Correct me if I'm wrong, but the GPS system doesn't require the device on the ground to send any signal to the satellites. The Chinese system allows for SMS, so it requires the ground device to send a signal into orbit. Won't that be a major problem when attempting to miniaturize the device, and what about battery life?
It's an interesting angle, though. It suggests that the satellites won't just be for a GPS system, but for minor cellular comms of some for as well.
Given that the PLAN (Peoples Liberation Army Navy, and no, I'm not making that up, it's what they call their navy) have taken recent delivery of a pubescent Aircraft Carrier, and that they're ramping up (pardon the pun) the capabilities of their naval forces, I'd suggest that the constellation that they're establishing will have a major role to play with the PLAN Communications system.
It's a neat idea, really, and one that I'm sure the Americans thought of when they first considered GPS for military purposes. Problem is, in those days, comsats were damned costly. GPS ones are too, but comsats, if included in the package, won't cost nearly as much as they would separately, and lets not forget, the Chinese are currently making all manner of high-tech kit - it's not all Cold War Soviet vacuum tubes anymore, they've got chip manufacturing plants and very well educated and experienced engineers too.
We (the West) should know this: We bloody well trained them!
On the comms or the GPS? I'll agree that if they're including comms facilities on the GPS constellation, then likely as not it'll be intended for military use, and will therefore be encrypted somehow; they have, though, stated that the GPS element of the system will be free for all to use, thus intimating that, that, at least, will be UN-encrypted.
You probably also know it would be quite a feat to break said encryption, not even really worthwhile unless there's a communications capability involved with this system. But even then, the Chinese are no slouches in Signals Intelligence and Cryptanalysis. NSA/CSS trained a whole lot of them during the latter parts of the cold war (There's a policy on both sides of deliberate ambiguity about it, but its a fairly open secret).
China had alot of issues with Soviet client states breaking their encryption schemes at the KGB and GRU's behest, such as the Interception facilities the Soviet Navy ran at Nha Trang and Da Nang, as well as the GRU's facility in the Kuril Islands. The PLA have about 35 years of good experience with Cryptography and I dont think it would even really be worth the time to break their encrypted signal, unless as I said there is a communications capability, but if they're smart they'll certainly use a system like Strategic Command uses on the Defense Support Program sats. I dont know what's classified and what isnt about that system so much, so look it up on Wikipedia if you're interested.
The CIA's SIGINT unit is widely rumored to assist the Third Department of the General Staff Department of the Central Military Commission (their Equivalent of NSA/CSS and GCHQ) with intercepting the Russians to this day. So we more than likely would already know how to deal with them if it came down to it because we more than likely know their methodologies.
The civilian signal will be unencrypted but the more accurate military signals are not. In times of war the civilian signals will be turned off or the accuracy drastically reduced. This is standard practice for all existing GPS systems, even GPS receiver manufacturers include a clause in their smallprint to the effect that they are not liable for the continuity or accuracy of positioning information in the event of conflict.
This is all common knowledge, I'm sure wikipedia covers it in great detail so you can all about it there. The US and Europe have been quite open about this capability and their intentions to use it in the interests of national security if required.
Explain how "global coverage" equates to world domination??? It's hardly the first time something like this has happened either. There's an undercurrent of "oh noes the Chinese, they're a massive monolithic group intent on warping your brains", when in reality it is us who are doing precisely what we accuse. Maybe that's the aim...