
The World Economy Runs on GPS. It Needs a Backup Plan - jedwhite
https://www.bloomberg.com/news/features/2018-07-25/the-world-economy-runs-on-gps-it-needs-a-backup-plan
======
jpatokal
Apparently Galileo, GLONASS and BeiDou don't count, because the backups for
this backbone of the _global_ economy have to be American?

[https://en.wikipedia.org/wiki/GLONASS](https://en.wikipedia.org/wiki/GLONASS)

[https://en.wikipedia.org/wiki/Galileo_(satellite_navigation)](https://en.wikipedia.org/wiki/Galileo_\(satellite_navigation\))

[https://en.wikipedia.org/wiki/BeiDou_Navigation_Satellite_Sy...](https://en.wikipedia.org/wiki/BeiDou_Navigation_Satellite_System)

I do wonder how many of these are supported by common hardware like mobile
phones, anybody have a pointer to a compatibility list? I know the Chinese
government had been prodding its manufacturers to add BeiDou support pretty
hard.

~~~
thermodynthrway
All satellite nagivation systems are trivially jammable. They use DSSS to
spread out codes and resist jamming but signal levels are still so weak at the
surface it's trivial to block.

Most phones are compatible with GPS(US) +Galileo(Europe)+Glonass(Russia). Most
of them also report which constellation the locks are from. GPS status and
toolbox on android is a fun way to see what you're connected to.

What we need, and will probably get soon, is inertial guidance based on laser
ring or fibre optic gyros in mobiles. You get a location fix every week or so
and it starts out much more accurate than gps.

The US system was first by maybe a decade or more so support is nearly
universal. The other systems are largely copycat, purposely compatible with
existing GPS receivers.

That's why it seems like we're relying on the US for GPS, they invented it and
had a full constellation in orbit before anyone else even thought of it.

Of course we're on the internet which was also invented by the US govt so I'm
not so surprised why "the backups for this backbone of the global economy have
to be American" in reference to GPS at least

~~~
maym86
> What we need, and will probably get soon, is inertial guidance based on
> laser ring or fibre optic gyros in mobiles. You get a location fix every
> week or so and it starts out much more accurate than gps.

Corrections every week? This isn't possible given the drift rates of high end
FOG or Lazer ring IMUs. A high-end marine-grade INS can cost over 1 million
dollars. These systems will typically provide un-aided navigation solution
drifts that are less than 1.8 km per day. This means that if the device were
left stationary for one day, due to slight errors in the sensors and imperfect
sensor calibrations, after integrating the position solution, the calculated
position after one day would be 1800 meters away from the sensors actual
position.

With ones that you can affordably put in a phone within minutes the drift will
be huge. You need something to regularly correct for the drift and currently
this is GPS.

~~~
kqr
So this is why my smartwatch can tell me my speed before it has a GPS lock,
including indoors? Very cool! But of course, as you say, the reports of my
absolute position are very inaccurate.

~~~
TickleSteve
No, any position-solution produced before a GPS lock will be due to the
approximation produced by either using the last-known position or the cell-
tower triangulation. That information is also used as a seed for the GPS lock
to speed up the time-to-fix.

------
civilitty
The longer I am alive the more I learn about how much of human civilization
depends on good faith and trust. Nearly every major system in use today is
chock-full of single points of failure that could have catastrophic
consequences but we keep chugging along, rarely stopping to think about the
"risk debt" we have accumulated - right up until a catastrophe. I don't know
if that should make me feel more secure or terrified.

Take power plants for example: they are all interconnected in large regional
grids and deal with such large quantities of power that bringing a power plant
online is a dangerous process that has to be coordinated with the rest of the
system. You have to spin up the power plant and make sure that you are in
phase with the grid before connecting your power output - all while accounting
for geographic distribution losses, predicted load changes, and so on.
Theoretically, any discrepancies (like power flow being too high due to phase
difference) would activate breakers and other safeties should an adversarial
actor decide to bring a power plant online online willy-nilly. Unfortunately,
the last few decades have shown that those safeties are barely able to handle
common scenarios, let alone an attack. There is a serious risk that a single
power plant could cause systemic damage to many devices in a region's grid but
for the entire history of the US, we have just assumed that anyone with tens
of millions of dollars to invest in a power plant is just too profit-driven to
pull off anything like that.

If the last few years (decades it seems) have taught me anything, it's that we
have to reevaluate many of the assumptions we have been holding about reality
and our peers. From the Target/Home Depot/Equifax breaches to Facebook's
Cambridge Analytica fiasco, we have just been way too lucky and way too
trusting. GPS is just one of many such cases, although a surprising one. I
never thought the world would put so much trust in a system created by and for
the US armed forces.

~~~
njarboe
A default trust society can be much more successful than default deceive/don't
trust society. The cost of default don't trust is high. I would say that the
wide adoption of the Christian value of honesty with everyone is probably one
of the main reasons for the rise of western Civilization. If we decide to go
back to a default don't trust society, we will loose something very valuable.
We should try very hard to avoid that.

~~~
sjwright
It's a bit parochial to hear someone in the twenty-first century describe
honesty as a particularly Christian value. You do know you're talking to the
whole world here? Most human cultures have valued honesty to a similar degree.
Even many animal communities value honesty.

~~~
cal5k
Religion has historically and continues to play a major role in geopolitics...
there's nothing parochial about it. The Christian belief system was
objectively instrumental in the creation of the West's institutions, system of
government, beliefs about trade, etc. You don't have to be religious (as I am
not) for this to be true.

~~~
wahern
People, especially Americans, conflate Christianity with Western culture. But
this is erroneous thinking:

1) Western liberal values are not co-extensive with Christianity. Christianity
is geographically much larger. This has been true historically, and even more
true today with the rise of Christian nations like South Korea and various
nations in Southern Africa.

2) Western liberal values came to predominate in Europe centuries, even
millennia, after Europe was Christianized.

3) Many Western liberal values are easily traced to pre-Christian movements,
such as Greek Stoicism.

4) The Christianity of most Western Europeans today is not the Christianity of
centuries ago, let alone millennia ago. The Protestant Revolution was like a
giant flask where people took Christian doctrines and mixed them together with
contemporary civil and philosophical values which emerged from the
Enlightenment and then the dawn of the scientific and industrial ages. It's
one thing to say that Christianity was conducive to the emergence of those
other phenomena; it's quite another to say that they _were_ Christian.

~~~
cal5k
1) Christianity has been a major export of the West through missionaries and
colonization. It was hardly the native religion of, say, Mexico or the
Philippines.

2) That's hardly a compelling case against the influence of religion on
Western values. It could even be a contributor, or neutral.

3) These values were well-documented but, for whatever reason, did not spread
to the Muslim or Hindu world first. Islam had its brief progressive
renaissance but was not able to sustain liberal values over the long-term.
There are some small exceptions - Ismaili Muslims are quite liberal - but
they're a tiny fraction of the Islamic world.

4) America was essentially founded by religious zealots and/or adherents to
marginalized religions. The very architecture of early America - the gothic
styling of Boston, for example - is of that era and persists. You can't wipe
out that kind of influence in 100 years.

I'm not saying religion is the ONLY factor, but I find it odd that people try
to ignore the impact it's had on the shaping of the modern world. I'm an
atheist so I view this more as a historical fact - I'm not a fan of organized
religion and would be perfectly happy if it went away.

~~~
Retric
It's a problem of timing and geography. Eastern Orthodox falls under the
Christian religious umbrella, but it's very different under the surface
demonstrating how western culture has influenced Christianity.

The Protestant Reformation was a religious movement, but ended up importing a
lot of western beliefs into Christianity. Democracy for example is a western
belief, Christianity is closely tied to Kings.

------
cameldrv
A few good possibilities:

1\. Cell sites have their own high precision clock, so they can go at least
10-20 minutes and probably longer without any difficulty.

2\. The site really only needs to see a single satellite to get time
synchronization if it has the almanac and ephemeris because it knows exactly
where it is and how far away the satellite is. In fact, in the presence of
noise, it can integrate over a long period to pull a jammed signal out from
under the noise floor.

3\. There are already a number of other terrestrial sources of time. TV
stations have precise timing, and a defined offset to GPS time. They also have
huge output power that is more difficult to jam.

4\. The cell networks can synchronize with each other. If the network simply
adjusts the time to be an average of neighboring cells and its own clock, they
will stay in sync. It's not required for the mobile phone network to have
correct absolute time, only correct time relative to other nearby network
elements.

~~~
ObsoleteNerd
Does anyone know if a hobbyist can pull the time from TV signals like you can
with an RPi/GPS-hat/etc? I'd love to have a bedside clock that pulls from TV
signal for no other reason than I didn't even know that existed until now.

~~~
berti
A quick Google struggled to find much. I did find that DVB-T has a transport
stream called "System_clock_descriptor" with identifier 0x0B [1].

[1] Pg. 22
[https://freeviewnz.tv/media/1216/freeview_dtt_transmission_r...](https://freeviewnz.tv/media/1216/freeview_dtt_transmission_rules_3.pdf)

------
hharnisch
We often use GPS as a way to synchronize time accross distances. Even Google's
data centers use GPS (and an atomic clock) for synchronization -
[https://www.google.com/amp/s/www.theverge.com/platform/amp/2...](https://www.google.com/amp/s/www.theverge.com/platform/amp/2012/11/26/3692392/google-
spanner-atomic-clocks-GPS)

GPS is such a weak signal that almost anyone transmitting ground based signals
on the right frequency could easily drown out GPS - and do spoofing with a
little extra research. So theoretically you could spoof near a data center and
mess up a lot of data powering 1000s of applications.

On top of this civilian GPS is made to be jammed and innacurate - there's a
better one the military has moved onto because of this (see the m-code
section:
[https://en.m.wikipedia.org/wiki/GPS_Block_IIIA](https://en.m.wikipedia.org/wiki/GPS_Block_IIIA))

So yes, relying on an easily jammed atomic clock hurtling through space seems
like a bad idea... But it's kind of the best we've got right now. At least
until the cost of putting your own satellite into orbit goes down.

~~~
tialaramex
Although the US has always fantasised about its military having a much better
GPS than everybody else, and it seems technically to be in a position to
arrange this, the reality is always that a $5 civilian device is available in
every store and the $8000 military device is back-ordered and won't be in
stock until after the war is won, so you use the civilian device even though
it's theoretically worse.

"Selective Availability" was the first incarnation of this pipe dream.
Civilian GPS would be deliberately corrupted by up to 100 metres and the
correct offset would be transmitted separately to authorised military devices.
But, see above, in practice when the US military needed GPS it found civilian
devices were available while accurate military ones were not, so it reduces
the induced error to zero and bought civilian kit for the Gulf War.

The M-code won't be deployed until 2022 (probably later, these things always
get delayed). That's when those Block IIIA birds "go live" even though some
will be in orbit for years before that.

Jamming the M-code is not really harder than jamming other codes, this is a
broadcast radio signal you can easily transmit a more powerful signal
yourself. The Block IIIA birds have an extra transmitter so they can increase
power... but they still can't drown out even a relatively disposable local
jammer.

Spoof genuinely is harder with an extra code... and this is the supposed
benefit with owning any of the GNSS systems, you can keep a secret shared key
that makes your system spoof proof until bad guys learn the key. But again, in
practice when war breaks out you turn out not to have thousands of expensive
military-only devices with the shared secret, so you rely on the civilian
stuff anyway.

------
ryandrake
Well, the aviation world still has VHF omnidirectional range (VOR) navigation
[1], where you can determine what direction you are to a VHF radio transmitter
based on phase difference. Unfortunately, the FAA seems hell-bent on phasing
them out in the USA, likely because money.

1:
[https://en.wikipedia.org/wiki/VHF_omnidirectional_range](https://en.wikipedia.org/wiki/VHF_omnidirectional_range)

2: [https://www.aopa.org/news-and-media/all-
news/2015/november/2...](https://www.aopa.org/news-and-media/all-
news/2015/november/24/faa-begins-decommissioning-vors)

~~~
perilunar
And Non-Directional Beacons [1]. Maybe not so popular in the USA, but common
around the rest of the world, and comparatively very cheap to run.

1: [https://en.wikipedia.org/wiki/Non-
directional_beacon](https://en.wikipedia.org/wiki/Non-directional_beacon)

~~~
ryandrake
Yep, the FAA has already decommissioned most, if not all, of our NDBs. They
seem very excited about making sure there's a single point of failure for all
non-visual airborne navigation.

------
squarefoot
Actually gaming GPS is well within the pockets of anyone.

[https://www.rtl-sdr.com/using-a-hackrf-to-spoof-gps-
navigati...](https://www.rtl-sdr.com/using-a-hackrf-to-spoof-gps-navigation-
in-cars-and-divert-drivers/)

The same principle is likely applicable to other standards as well, until the
day they add encryption, which will probably need a lot of time and research
to overcome the inevitable associated timing problems.

If doable at military level, the possible scenarios are catastrophic: country
A launches say 5 test missiles, country B from nearby hidden submarine
launches 5 much smaller and stealth jamming missiles. The jamming missiles
approach the bigger ones then jam them into believing they're slightly off
course forcing them to adjust, while in reality they're being slowly directed
to country C. Of course any loss of control by ground base should be
interpreted as self destruct by the missile, so it'd be near impossible to do
it actually, but if other signals could be spoofed as well as positioning,
then that would be a problem.

~~~
ericpauley
This is why missiles don't use GPS. (at least U.S. ones as far as I know)

They use a highly precise inertial measurement unit to track their location
since launch.

~~~
maeln
They use GPS and a lot of different technique because the IMU need regular
correction. But the main source of trust is the IMU. By jamming the GPS signal
you can induce more drifting, but you would have to jam it for a long time to
induce a very big drifting (and even them, it might be compensated by the
other technique employed).

------
eltoozero
US, Russia, and China all have intependant “Global Positioning” Systems, GPS,
GLONASS and BDS.

All similar in function and implementation.

The coolest part about GPS is the fact that temporal relativity is employed to
establish a 3D location from accurate flying clock radios, that’s rad.

~~~
wyldfire
There's a relativity correction step for communication between Iridium
satellites and mobiles. I always thought that was really cool.

------
cjhanks
People do not truly understand not only the dependency on GPS as a canonical
source of both position and time. Navigation and nationally productivity can
totally break down if it were to disappear.

But that's an extreme case. Localized and targeted GPS spoofing is not science
fiction. What's worse - the GPS spoofing can be designed to warp world
geometry in particularly nefarious ways to coerce the trajectory of objects
for specific purposes. It's not even that expensive, it's just a different
algorithmic problem.

Those algorithms _will_ become trivial in the future - and they will have not
been tested by most (if any) of the various autonomous service providers.

~~~
cup-of-tea
Some people do understand. That's why many countries have made their own
independent "GPS" systems.

~~~
cryptonector
More of the same easily-jammable schemes is not a real solution. But all
wireless location/navigation/time-distribution mechanisms will be easily
jammed. The only solution is fantastic improvements in inertial navigation
devices.

------
sebcat
Made me think of an old Phrack article, "Low Cost and Portable GPS Jammer".
Worth a read!

[http://phrack.org/issues/60/13.html#article](http://phrack.org/issues/60/13.html#article)

------
reaperducer
Not shocking to anyone who set up GPS systems in the early days. Or anyone who
lives in a city with lots of shiny buildings. Or lives near a military
facility. Or drives the Beltway around D.C. Or...

------
lileeyao
BeiDou is actually more advanced as it supports full-duplex communication,
which essentially allows you to send message to the satellites.

~~~
bdamm
And then what? A.la. personal emergency beacons?

~~~
ObsoleteNerd
Satellite based SMS would be pretty amazing for hikers/campers/etc.

~~~
isostatic
[https://www.globaltelesat.co.uk/isatphone-2-satellite-
phone-...](https://www.globaltelesat.co.uk/isatphone-2-satellite-phone-rental)

------
brian-armstrong
If you're curious how GPS works, this is a surprisingly approachable guide
where a guy built his own and detailed lots of the knowledge
[http://lea.hamradio.si/~s53mv/navsats/theory.html](http://lea.hamradio.si/~s53mv/navsats/theory.html)

------
Bucephalus355
FYI the 24 GPS satellites are all in Low Earth Orbit. Well within the reach of
missile technology today. These will be taken out within minutes of the next
war. This is why the Naval Academy as of 2 years ago teaches navigation by
sextant. Was in the Army as late as 2013, and they (at least that unit) almost
never let us use GPS during training (only USGS maps, protractors and compass)
for this reason.

~~~
justinator
Once all the GPS (or similar) satellites are knocked out, uh, what are you
going to use now fight the war?

On _either_ side?

And anyways, what country has the budget to knock out _twenty four_ satellites
in quick succession?

And what if this doesn't work? I'm having a hard time thinking the US Gov.
doesn't have a shadow GPS constellation up there, somewhere, but I will
concede this is the most wahoo part of my meanderings...

I think knocking out GPS is a rather risky move to even try.

~~~
ggg9990
> what country has the budget to knock out twenty four satellites in quick
> succession?

The only countries between whom a war would be a globally consequential event:
the United States, China, and Russia.

~~~
threeseed
Actually any country with a nuclear weapon should be on that list.

And that is quite a few: Israel, UK, France, India with North Korea/Iran not
that far behind.

~~~
ars
That's not enough - you also have to be able to deliver the warhead to the
satellite.

It's not very easy to do.

------
shanev
FOAM [1] is trying to solve this. They're using a distributed network of radio
beacons which offer location services using time synchronization.

[https://foam.space](https://foam.space)

~~~
Uberphallus
Every day I discover a new use case crammed into a blockchain with a
sledgehammer.

------
max_
These blockchain fellas and are working on an Ethereum's alternative.

[https://blog.foam.space/introduction-to-proof-of-
location-6b...](https://blog.foam.space/introduction-to-proof-of-
location-6b4c77928022)

