
China's GPS 'rival' Beidou - Sami_Lehtinen
https://www.bbc.com/news/technology-45471959
======
nabla9
Multi-GNSS support increases the reliability and signal availability.
Commercial chipset will usually add support for all of them and don't just
choose one.

Newest phones (like iPhone 8) work with GPS, Galileo, Glonass, and QZSS.
Beidou support will come in the future.

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kejaed
Note you can buy off-the-shelf GPS modules today that will work across all
four GNSS:

[https://www.u-blox.com/en/product/neo-m8-series](https://www.u-blox.com/en/product/neo-m8-series)

~~~
donquichotte
Exactly. At the moment, the consumers benefit from the increased accuracy and
coverage provided by multiple GNSS.

Sidenote: the ublox M8 chips are a pleasure to work with, and there are
variants that have IMUs (gyros and accelerometers) on board for sensor fusion.
All for <10$. What an exciting time we live in!

~~~
eiaoa
> Sidenote: the ublox M8 chips are a pleasure to work with, and there are
> variants that have IMUs (gyros and accelerometers) on board for sensor
> fusion. All for <10$. What an exciting time we live in!

I wish someone would build a USB data logger using one of these. I still use
one to geotag photos and record trips, but all the available models use old
GPS-only chips and can be pretty jumpy when reception is poor. Having one that
fused multiple GNSS and had an IMU to smooth out some of the random jumpiness
would be ideal.

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Analemma_
It’s interesting and odd to me that Beidou requires two-way communication, as
opposed to other satellite tracking systems where the receivers are purely
passive and satellites only transmit, not receive. Is there an explanation for
why this was done?

~~~
nraynaud
I am highly skeptical of this claim, it's either for higher accuracy of
military stuff, or an internet connexion to get a key or the ephemerides or
something. But nobody is sending signal to a satellite 21000km from the
surface straight from a watch-sized device.

~~~
tialaramex
I agree with the thrust of your post, but Um Actually...

The current Breitling Emergency (a bulky men's watch, but it wouldn't look out
of place on some big out-of-doors type guy's wrist) is a working PLB
transmitter.

So that means signals from it can be received not just 21000km up, but 36000km
up where Geostationary birds live.

If you activate it, that watch will transmit the digital signal with its
unique ID in it, and assuming you filled all the paperwork out soon after
somebody from the relevant local emergency response (maybe a coastguard,
mountain rescue, that sort of thing) will be phoning your emergency contacts

"Hi, do you know nraynaud? They went flying today? OK, do you know where they
were headed? We have an emergency transmission from their beacon so we're
going to send somebody to take a look and check they're OK. We'll let you
know, thanks".

A "real" beacon would be better, more robust, better battery life, easier and
more obvious for random strangers to operate if you're unconscious, not to
mention much cheaper. But the Emergency has the advantage that you'll actually
have it when shit goes wrong, because it's your watch.

------
majia
"We are likely to see an increased bifurcation of the world into two camps -
'pro-China' and 'pro-US'", says Blaine Curcio, founder of Orbital Gateway
Consulting

Why do some people view it as a with-us-or-against-us problem? Combining
beidou with GPS gives a better accuracy. Some competition and collaboration in
the GPS field can benefit us as a whole.

~~~
liftbigweights
> "We are likely to see an increased bifurcation of the world into two camps -
> 'pro-China' and 'pro-US'", says Blaine Curcio, founder of Orbital Gateway
> Consulting

Why just two? If our stranglehold on the world breaks, the EU and Russia are
easily capable of carving out their sphere of influence.

People really underestimate how populous and wealthy and powerful the EU is.

It's strange how the narrative changes in such a short time period. Just 10
years ago, I remember people talking of "chimerica" as if the US and china
were going to merge into a single world ruling entity.

~~~
tdhoot
The EU is wealthy but has limited power projection. Only France and the UK can
realistically be considered great powers, and even then not on the scale of
the US, China, or Russia.

~~~
kelchm
France and the UK? What about Germany?

~~~
Leherenn
In term of military power mostly I guess. It's the only EU nations with
nuclear weapons, aircrafts carrier, nuclear submarines, ...

~~~
tdhoot
Correct. Germany is an economic powerhouse, but lacks military might and
therefore power projection.

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tyingq
I was curious what Beidou meant, apparently it refers to the "Big Dipper":
[https://en.wikipedia.org/wiki/BeiDou_Navigation_Satellite_Sy...](https://en.wikipedia.org/wiki/BeiDou_Navigation_Satellite_System#Nomenclature)

~~~
jewelry_wolf
Yep, Big Dipper as part of Ursa Major translates to something used as a wine
vessel about 2 to 3 thousands year ago.

[https://en.wiktionary.org/wiki/%E6%96%97](https://en.wiktionary.org/wiki/%E6%96%97)

------
sbradford26
GPS has become so ubiquitous I honestly forgot that it was something that
could be owned. It is cool to see some competition in the GPS world.

~~~
nutjob2
GPS systems are not so much 'owned' as 'paid for'.

~~~
azinman2
And designed and maintained...

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comboy
Why is 'rival' quoted?

~~~
nutjob2
Because GPS do not rival each other in any practical sense, instead they
complement each other. More GPS systems means more satellites means greater
accuracy for users.

Let's hope even more countries get into GPS "rivalry."

~~~
comboy
Oh, I guess you're right. In my mind it was like "not really a competition" in
a negative aspect but it turns out the negativity was in my mind.

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everybodyknows
>... even precision missiles.

So if GPS were to be jammed, or disabled by a hack into the ground control
systems -- PLA missiles would still work just fine. Hmm.

~~~
craftyguy
Due to COCOM limits, GPS was never an option for China to use on their
missiles.

[https://en.wikipedia.org/wiki/CoCom#Legacy](https://en.wikipedia.org/wiki/CoCom#Legacy)

Edit: I'm wrong.

~~~
Retric
COCOM is a non issue when building your own devices from scratch.

GPS satellites are transmit only so they can’t impose such limits directly
it’s device manufacturers that implement COCOM.

~~~
snops
You are right that COCOM is not the issue, but there are other measures.

The new military M code transmitted from the latest satellites is encrypted
with a frequently changing key, so in the event of a war the DOD can disable
the civilian signal as the M code will work standalone, hence a third party
nation cannot rely on GPS.

The previous P(Y) code was also encrypted, but is theorised to need the
civilian C/A code as well to work.

~~~
eiaoa
> so in the event of a war the DOD can disable the civilian signal as the M
> code will work standalone, hence a third party nation cannot rely on GPS.

They also had the option in older satellites of turning on selective
availability, which would _degrade_ the civilian location service from 5-meter
to 100-meter accuracy without affecting the military service. Purportedly
newer GPS satellites don't have the option anymore.

[https://en.wikipedia.org/wiki/Error_analysis_for_the_Global_...](https://en.wikipedia.org/wiki/Error_analysis_for_the_Global_Positioning_System#Selective_availability)

~~~
rangibaby
> Purportedly newer GPS satellites don't have the option anymore.

That does sound suspiciously like something the military _would_ want you to
believe

~~~
vlovich123
Selective availability was defeated a very long time ago so no reasons to
doubt that the military gave up on it. Pretty sure they're just using an
encrypted transport for the military signal so they can do whatever they want
to civilian GPS wholesale without impacting the military. However, I'm not
sure how that will work since it underpins our entire economy from logistics
to air travel. On the other hand, at the point the military is disabling
civilian GPS probably the economic impact is less of a concern.

------
pietroglyph
No one seems to have mentioned that the US has actually blocked GPS signals
before for military reasons (during the Kargil war in 1999):
[https://timesofindia.indiatimes.com/home/science/How-
Kargil-...](https://timesofindia.indiatimes.com/home/science/How-Kargil-
spurred-India-to-design-own-GPS/articleshow/33254691.cms)

There's a good reason and precedent for China (and others; see GLONASS, IRNSS,
Galileo) to be afraid of this.

~~~
jhayward
No, the US has never done any blocking in the GPS system. The article refers
to a request by India for access to the military GPS signal and military
equipment, which was not granted.

The US, as well as virtually all other technological powers, does have the
capability to jam GPS signals using ground, sea, or air-based jamming
platforms but those are not part of the GPS system.

~~~
pietroglyph
The United States actually does have the ability to selectively degrade
signals. I don't know enough to comment on this capability in more detail
(another comment seems to indicate that it is through jamming). A relevant
excerpt (from 2000) is below:

> Additionally, we have demonstrated the capability to selectively deny GPS
> signals on a regional basis when our national security is threatened.

[https://www.faa.gov/about/office_org/headquarters_offices/at...](https://www.faa.gov/about/office_org/headquarters_offices/ato/service_units/techops/navservices/gnss/gps/policy/presidential/index.cfm?print=go#1)

~~~
vlovich123
Selective availability was defeated a long time ago which is one of the
motivations for Clinton formally turning it off in 2000. Also while I'm sure
that the US military is fully capable of turning off GPS satellites however
they want the efficacy of this is probably limited considering the coverage of
GLONASS + EGNOS.

~~~
pietroglyph
The point of that article is that a main justification for _turning off_
selective availability was that the US could still deny access in certain
geographic areas. Selective denial != selective availability.

------
justfor1comment
India did something similar a few months ago. Each country wants to build it's
own GPS for military purposes. At some point we have to stop calling it
'Global' Positioning System.

~~~
kec
The "global" refers to the fact that it works globally, not that it exists for
the good of humanity.

Navstar (owned by USDoD, what is commonly called "GPS"), GLONASS and soon
Galileo all have global coverage.

~~~
romwell
Yup, GLONASS = GLObal NAvigational Satellite System.

Although one should note that name is the intention; it has not always had
global coverage (it does now), and may not always have global coverage in the
future (say, if they decide to increase the precision in a strategic area at
the cost of loss of coverage in others).

------
csense
So China has the technology to destroy satellites [1], and is developing
alternatives to US satellites.

Does this make anyone else nervous?

Maybe Trump has a point when he says we should stop letting China steal our
technology.

[1] [https://en.wikipedia.org/wiki/2007_Chinese_anti-
satellite_mi...](https://en.wikipedia.org/wiki/2007_Chinese_anti-
satellite_missile_test)

~~~
weregiraffe
>So China has the technology to destroy satellites [

Any country that can launch a satellite has a technology to destroy one. It's
called a missile. You don't even need to go to orbit - just intersect the
orbit of the target and dump a bucket of nails in its path.

~~~
JumpCrisscross
> _Any country that can launch a satellite has a technology to destroy one_

It's easier to put something in orbit than to knock something out of orbit.

~~~
slededit
You can destroy something without taking it out of orbit. The pieces will
happily carry on along their orbital trajectories.

~~~
JumpCrisscross
It's easier to put something in orbit than to hit something in orbit.

~~~
slededit
Well I'll disagree with my own unsubstantiated claim. Consider that its easier
to manufacture flak shells than make airplanes. The same applies to space.

