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back to article China switches on 'BDS' civilian nav-sat rival to GPS

China's Beidou satellite navigation system has gone live to civilians, providing the Chinese public with accuracy comparable to GPS without reliance on American military hardware. Beidou's coverage isn't global yet, the Chinese only have half a dozen satellites in the sky (compared to the 33 GPS birds aloft right now, albeit a …

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Silver badge

Switching off GPS

"the US military - who reserve the option of denying GPS service, though this has never actually happened. "

On the morning after the World Trade Center attacks a friend was told by his GPS that his house was doing several hundred miles an hour over the North Sea.

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Anonymous Coward

Re: Switching off GPS

The US military system which is more accurate than consumer GPS and encrypted, we don't get access to this system ever.

What they probably switch off is the consumer GPS leaving their own system still going.

Annoyingly the EU's Galileo GPS will also be de-activated by the Americans if they request it.

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Happy

Re: Switching off GPS

And?

According to GPS , my position at work frequently shifts by about 2 miles east, placing me firmly underwater.

Then I come back to work after drowning for 10 minutes

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Anonymous Coward

Re: Switching off GPS

"Annoyingly the EU's Galileo GPS will also be de-activated by the Americans if they request it."

AFAIK, there is only some extremely vague agreement that the US military would be able to locally jam public Galileo signals in the region of some conflict. As the EU plan to use Galileo augmented by EGNOS to fly and land commercial aircraft, the USA would have to come up with a very convincing argument for the EU to cooperate with any interference with Galileo.

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Anonymous Coward

Yeah right.

> but the EU publicly guarantees that it will never be switched off.

I trust the EU even less than I trust the Chinese Government.

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Happy

A Hat Tip to William J. O'Brien, an American engineer

who invented what was later known as Decca Navigator. - although it operated on position fixing by means of phase comparison of continuous wave transmissions whereas GPS is based upon time..See: < https://en.wikipedia.org/wiki/Decca_Navigator_System > and < https://en.wikipedia.org/wiki/Global_Positioning_System >.

Decca was knee-capped by the EU and the principal espoused at that time seem to have been happily ignored in the development, and financial support, of Galileo.

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Re: A Hat Tip to William J. O'Brien, an American engineer

It is worth noting, however, that the UK has committed to operating eLORAN until the year 2022. I spent some time on a foreign warship recently and navs made effort to specifically point out to me how much he appreciated that (particularly given that test jamming of GPS is becoming more common in naval exercises as time goes on), which was nice.

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ICBM's navigation

ICBMs do not use GPS or any satellite navigation. http://dspace.mit.edu/handle/1721.1/57986 They observe stars in space to get their position.

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Facepalm

Re: ICBM's navigation

But what if it's cloudy?

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That paper is about the usefulness of using stars as an aid to improving the accuracy of the inertial measuring system. There is another paper from Harvard relating to the use of gps.

adsabs.harvard.edu/abs/1982guco.conf...28B

The mgm134a uses a combination of IMS and GPS although that was a 1990's prototype. LGM30g3's as used by the usa right now are inertial only as were the 'peacekeepers'. Of course they could have been updated to include star tracking and gps and just not told us. I think the Indian ICBM's (agni?) use gps to augment the IMU and the Russian Topol's use glosnass to augment an IMU. iirc :-) To be fair, both could have a guy sat in there with a map and a joystick steering the damn thing.

If I were designing an ICBM I would probably be considering using star tracking and gps \ glosnass to augment an IMU.

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Re: ICBM's navigation

or daytime ;-)

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FAIL

Re: ICBM's navigation

Last time I looked, ICBM's flew above cloud cover...

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FAIL

Re: ICBM's navigation

And once above the bulk of the atmosphere, you can see the stars even when on the day side of the planet.

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Re: ICBM's navigation

The other reason ICBMs do not use GPS is because the way you know you are in a shootin' war toe-toe with the Russkies - is when all your GPS sats are shot down.

GPS is very useful for the submarine to know where it is when it launches and it does save time sitting on the surface while a bunch of navigation officers with sextants take sightings, that;s why the predecessor to GPS was invented by the Navy.

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Re: ICBM's navigation

So when the little gray/green with just a touch of fuchsia space folks arrive to a deserted planet after the star charts have shifted slightly and start throwing switches to see just how smart we were at which point the ICBMs will become a self destruct system. Their last words will be, "Oh shit! Those fucking clever little bastards!"1

1 Approximate translation since there will be no direct correlation to the word shit. Space travel will have negated the need to actually eat and shit. Space folks will be genetically engineered chimeras part animal and part plant which provide a self feeding and fertilizing organism that is maintained by the background radiation in space. The benefits of not needing food stores or waste management combined with no need for radiation shielding is what will have made long term space travel possible. Of course the space folks not directly blown up by the ICBMs will actually become so large they will be stranded here and need to duck to avoid being struck by the moon. At least that's what I gather from talking with some excitable fellow who entered a disappearing blue police box not long ago.

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Re: ICBM's navigation

Huh? Invented by the US Navy?

http://en.wikipedia.org/wiki/Sextant

"Sir Isaac Newton (1643–1727) invented the principle of the doubly reflecting navigation instrument (a reflecting quadrant—see Octant (instrument)), but never published it. Two men independently developed the octant around 1730: John Hadley (1682–1744), an English mathematician, and Thomas Godfrey (1704–1749), a glazier in Philadelphia. John Bird made the first sextant in 1757. The octant and later the sextant, replaced the Davis quadrant as the main instrument for navigation."

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Bronze badge

Re: ICBM's navigation

Sorry, I think I may have misread you ant thought that you were positing that the USN invented the sextant.

Anyway, along the lines off the sextant, this may interest some:

http://www.westsea.com/tsg3/octlocker/octchart.htm

But, on my first quick pass of the article, I found nothing in it discussing how, according to Gavin Menzies, the Chinese were able to circumvent... Ummm, circumnavigate the globe by their own sextant or quadrant-like/astrolage-like instruments. Per his book from circa 2003/2004, or when i read it, the Chinese Eunuch Admiral Zheng He ("Jung Huh", not "zzeng hee") and other 1421-era Chinese fleets could start from China and sail to ANY point on the globe, and arrive to within a few miles of their intended destination, at which point land sightings would make up for minor error. Per his book, when the Portuguese, Spanish, or others attempted the same level of accuracey, even years or decades later, they were dozens if not hundreds of miles off course, but managed to close the error gap, but only more years later, and with more modern instruments that had then become available. I do not know how accurate Menzies' account of history is, but if he is correct, it could be sobering.

Just imagine if China had not abandoned her earlier maritime feats. Might have changed the course of history since the 1700s had China had maintained her robust, most-powerful navy. But, it seems the economy, fiefdoms, civil wars, shifting borders, and incurrsions by outsiders from at least 3 up-and-coming powers expoited the local disarray. (Plus, Vietnam would probably have just run out of trees by the 1730s, and Vn is probably STILL seething over all those trees that were cut down.)

Cheers!

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Bronze badge

Stages, GPS, INS, Cruise, Descent, Ballistics...

From reading:

http://www.faqs.org/espionage/An-Ba/Ballistic-Missiles.html

, it seems to me that GPS *might* be used, but if it is, it would be during launch. That makes sense since during launch, if a launching nation's GPS system is still intact, a missile can know its position AT launch and maybe for a few minutes during the ascent phase. Otherwise, I presume that GPS inputs are fed to the missile for as long as GPS is not knocked out.

Then, during ascent, the missile is constantly calculating/computing all along its path. At some point, during cruise (if cruise is well above the atmosphere, far enough to count as having "exited" the Earth), it may or may not launch one or more MIRVs, and then, during descent, launch off one or more, or all remaining warheads, which may or may not be finned for maneuvering. If finned, or if using thrusters, they then would be MaRVs, or Maneuvering Re-Entry Vehicles. I thought, in my past thinking that is, that MarVS maneuvered not so much to improve targetting accurace, but to ACTIVELY and not passively evade countermeasures or anti-missile missile systems. I knew in the past of decoys in MIRVs, but thought that I in the past read the MaRV systems were good enough and fast enough to not need decoys, meaning more RVs could be carried, or they could be lighter RVs to move a bit faster before launching the warheads.

I though that the MaRVs could do things like cork-screw maneuvers, too, not just fire off decoys and counter measures. Been a long, lonnnng time since I last read this stuff, since maybe the mid 80's. I even forgot about the MX missile. The article was a nice refresher about the diffs tween SLBMs and ICBMs and how the USAF distinguishes ICBMs by ranges (Short, Medium, Long) whereas the USN does not.

Also, it was interesting to read that the V(#) rockets, some 580 of which were launched into the UK (I suppose as terrror devices, not anti-military infrastructure weapons) were, to this date, the deadlies ballistic missiles.

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Anonymous Coward

Re: ICBM's navigation

Like Patrick Moore but slightly more quickly? I mean, when he was still around, bless him. what if they find some exciting new object, do they have to stop and phone it in?

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Fell Free to Step Wisely into those Immaculate Fields of XSSXXXXually Active MegaPlay ........ but be warned and humbly advised, LOVE is terrifying and terrific ...... in fact, practically out of this world.

Wanna Play LOVE? Do you have AIMove which can be Inputted to Output to Further Secure Control?

There is no possible earthly defence against LOVE, nor battles to fight against ITs Virgin Soldiers and Experienced Experimental Lovers. ...... Two Devilishly Heavenly Callings at QuITE the Same Opposite Ends of the Scale.

And yes, I did have a long think before I wrote that last stanza ....... and IT say what I know to be currently true.

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"who reserve the option of denying GPS service, though this has never actually happened."

Are you sure about that- I'm pretty certain that there was quite a few outages during the first gulf war. Fortunately civilian GPS was in its infancy so it would not have received a lot of notice. However the company I worked for sold surveying solutions around GPS and I remember a lot of disgruntled customers.

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Re: "who reserve the option of denying GPS service, though this has never actually happened."

There were also rumours that the GPS signals over the gulf were gradually skewed at certain times to lead enemy convoys off track. Rumours ...... often interesting and inventive?

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Re: "who reserve the option of denying GPS service, though this has never actually happened."

In the first Gulf war the Selective Availability (ie the signal position poisoning) was actually switched off.

There weren't enough military GPS units to go around and so most troops were using civilian units.

It was pretty obvious to the US than the Iraqis hadn't yet developed their own invisible, 45min to London, GPS guided, WMD carrying, cruise missiles.

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Bronze badge

Re: "who reserve the option of denying GPS service, though this has never actually happened."

In the early 90s, I worked for a courier company that IIRC considered using Trimble Navigation devices. We used to deliver their gear to local area outfits, and IIRC, sometimes to airlines for shipping. I recall around Java Avenue, Montague Expwy, Lawrence Expwy, and a few other places seeing old beat-up cars with huge tubes/cans and whip antennae swinging to and fro, some tied to the hood (bonnet in the UK?) all the way from the trunk (boot in the UK?) of the car. Then, within years, such sightings vanished or diminished greatly as smaller devices from competitors and Trimble came along.

Ahh, nostalgia/memory lane....

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Re: "who reserve the option of denying GPS service, though this has never actually happened."

"It was pretty obvious to the US than the Iraqis hadn't yet developed their own invisible, 45min to London, GPS guided, WMD carrying, cruise missiles."

It was pretty obvious before the second Gulf War too, unless your name was George Bush or Tony Blair.

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Re: "who reserve the option of denying GPS service, though this has never actually happened."

"In the first Gulf war the Selective Availability (ie the signal position poisoning) was actually switched off."

Only after a few days. When the invasion started the USA initially switched off the civilian signal worldwide.

That was "somewhat disconcerting" for a friend of mine 10,000(*) feet over the Pacfic, halfway between New Zealand and the Chatham Islands who was using it as his primary nav tool when it suddenly went away. There's a lot of water out there and not much land.

(*) Beechcraft Barons can fly much higher but they're not pressurised and running on system oxygen is incredibily fatiguing. He managed to get a mobile phone signal by climbing to ~20,000 feet and got the nav data needed to do it app by hand - and a full on bollocking by the aircraft's owner plus NZ's Civil Aviation guys later on. GPS wasn't approved for primary nav, specifically because it _could_ be turned off. That was despite relying on it it being standard practice on ocean flights for quite a while.

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Joke

Futurama

In the future, I'm going to build my own satellite navigation constellation, with Blackjack, and hookers.

In fact, forget the Sat-Nav constellation.

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Re: Futurama

Count me in on that, ElNumbre :-) ..... as AI Pioneering Member

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I like the European approach

Hmm, the goal was to be independent of GPS... so....

1. Announce a GPS competitor

2. Others will try to do the same as it seems like a good idea

3. Don't deliver

4. Enjoy having a wide variety of competitors at very little cost

Seriously, why else would they have allowed the US to turn off Galileo on request?

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all these satellites

and yet notice they still haven't found madeline mcann

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Re: all these satellites

Do you really believe that surveillance satellites work like those in films such as "Behind Enemy Lines"?

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Re: all these satellites

The best quote I ever saw was "Osama could be sunbathing naked in his backyard waving at them, but unless they know precisely where to look they'd never see him."

Who knows, perhaps OBL was doing that from time to time.

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Anonymous Coward

A few more details

The different satellite navigation systems are GPS (USA), GLONASS (Russian Federation), Galileo (European Union), Compass (China).

Of course you can now ask why is there Galileo and GLONASS, since Russia is not that far away from the EU, then again, several countries including France, Japan and India are in the process of developing regional navigation systems. (http://en.wikipedia.org/wiki/File:Comparison_satellite_navigation_orbits.svg).

Satellite navigation system switchoffs happen, but very rarely: http://en.wikipedia.org/wiki/2008_South_Ossetia_war#Russia

The civilian signal of GPS is in many cases too inaccurate and is therefore corrected with A-GPS, but there is also the U.S. FCC's 911 requirement to make the location of a cell phone available to emergency call dispatchers. More GPS restrictions on civilian use here: http://en.wikipedia.org/wiki/Global_Positioning_System#Restrictions_on_civilian_use

Fancy feeling a bit paranoid? GPS tracking: http://en.wikipedia.org/wiki/GPS_tracking#Data_loggers

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Re: A few more details

The reason for Galileo was that ArianeSpace/BAe/Astrium/Thales were looking like they might need a bit of help in the absence of any nice wars that were going to destroy lots of expensive fighter planes.

And it allowed the French to demonstrate their natural superiority over the Americans.

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Re: A few more details

I have a nice Chinese-made Holux m241 data logger. It's the size of a Kodak film canister and can store 32K points spaced 50ft apart (310 miles/500km) and the AAA battery lasts for about 3 weeks continuously on.

I use it for recording my motorcycle trips - http://www.everytrail.com/profile.php?user_id=42415

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So when do we start to see consumer SatNav

That uses all four systems seamlessly?

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Thumb Up

Re: So when do we start to see consumer SatNav

I don't know about all four, that would seem a bit premature, but Garmin's Etrex series does GPS with EGNOS and GLONASS quite happily.

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Re: So when do we start to see consumer SatNav

I was surprised the other day to see my Xoom uses GLONASS. If you install "GPS Status" and you have a new enough chipset, it shows GLONASS satellites as squares instead of circles.

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Re: So when do we start to see consumer SatNav

I have a GPS which uses both GPS and Galileo, with added SBAS (WAAS./ EGNOS) support. There are some GPS chipsets around which support GPS, Galileo and GLONASS. I am not sure if there are yet any which also support the Chinese system as well.

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Silver badge

Re: So when do we start to see consumer SatNav

Probably quite soon. Most recent phones use both GPS and Glonass, because Russian import duty is a lot cheaper that way, and having designed the chip that does both, they may as well put it in every device. Also, while the accuracy of both systems is approximately the same, the accuracy if you use both systems together is a lot better.

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Re: So when do we start to see consumer SatNav

Thanks everyone. I didn't realise we were already pretty integrated.

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Re: So when do we start to see consumer SatNav

Before the Americans allowed civilians to use military-grade GPS (as they do now), it was common for remote area survey to have multi-system receivers that used the Russion system for it's superior accuracy, and GPS for it's superior availabilty.

Systems like that are less useful for walkers and drivers, because the Russian satallites don't spend enough time over the rest of the world to be helpful if you aren't standing still and waiting for one to come over.

Now that civilians have military-grade GPS, there is less need for multi-system receivers, and what need there is, is often met by other enhanced-accuracy systems which don't involve waiting so long.

All new systems have better accuracy than the old GPS system, and a new GPS system is coming too. The new GPS system will have better civilian accuracy than the old one -- I don't know how this will make it compare to the Russian/Euro/Chinese systems.

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ACx

Oh FFS, this is insane.

So every country will have to have its own set of 30 odd GPS sats in orbit because no one trusts any one else. US, China, Russian, then perhaps India, Pakistan, EU, N Korea, Arab states etc, etc. OK, not quite, but you know..... 240 sats to start with.

Cant this poxy planet do anything freely as one? Oh no. "We" must have our own ability to feck every one else over, or find our way to Primark.

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Thumb Up

"Beidou's coverage isn't global yet, the Chinese only have half a dozen satellites in the sky"

In Communist China, you find satnav!

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Bronze badge

This is the main reason why the US originally built GPS, in fact.

By "in fact" he means, of course, "in some alternate universe".

GPS is a generic navigation system. It was proposed and developed as a generic navigation system. There are, and were, many specific uses, and many suggested specific uses before, long before, and immediately before the system was built. That is the wonderful nature of useful navigation systems.

In the 'immediately before" catagory is civiiian use: after flight 007 was shot down by the Russions for straying into controled airspace, the decision was made that the US would provide a global positioning system for civilian aircraft. That was in 1983: the first satelite was launched 6 years later.

In the "long before catagory" was a suggestion that some kind of automatic digital navigaton system would be useful so that ICBM's didn't need to be reprogrammed to know their start location everytime they were switched to a different launch pad (the "racetrack" proposal). Not for intercontinental navigation -- just for location while stationary before launch.

This was by no means the "main", or even a "significant" reason why the US wanted a Global positioning system -- there was never any suggestion that the "racetrack" proposal would be Global -- the proposal was that Inter-Continental Ballistic Missiles be rail-roaded between alternate launch sites in the US.

Just to be clear, there is no suggestion that the US originally built GPS as a navigation system for ICBM's. None. Zilch. Nada.

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Mushroom

Re: This is the main reason why the US originally built GPS, in fact.

The early Navstar satellites also had another feature, they had EMP detectors so they could spot nukes going off and detect exactly where they went boom. One of the requirements was to be able to tell which side of the wall in Berlin vaporized first. There had to be more stuff on the SVs as well since they were about the size of a bus.

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Trollface

Do you prefer depending on the Pentagon, or the commies?

No.

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FAIL

Edward Teller would be so pleased,,,

Surely this is the kind of world that would make a paranoid schizophrenic like Dr Strangelove, aka Edward Teller, very very happy - just think of all those nubile females down there in the coal mines with you while the surface of the Earth cools,,,

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FAIL

Nothing like checking one's sources or knowing what one's talking about...

«Galileo only has three birds in the sky right now». Strange, is it not, that the people responsible seem to think there are four ? But then again. I'm reading el Reg....

Henri

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