
Study finds that a GPS outage would cost $1B per day - jonbaer
https://arstechnica.com/science/2019/06/study-finds-that-a-gps-outage-would-cost-1-billion-per-day/
======
myself248
Nobody's talking about what might cause an outage. There are three basic parts
to any GNSS: The control segment, the space segment, and the atmosphere on the
way back down.

The control segment is run by the military so let's assume it's as secure as
any other military network, and that attacking it would be seen as an act of
war. And there are several constellations run by various countries, who do not
represent a common target.

The space segment is vulnerable to space weather, but has proven pretty darn
resilient so far. Even if a big CME or something knocked out a few satellites,
there are ton of them up there, and most of the most critical applications
only rely on timing, not positioning, and would work fine with a degraded
constellation.

The atmosphere is where it gets interesting; an airburst nuke will make the
ionosphere basically opaque to such signals for quite some time. How long
depends on a lot of details, but assume several weeks. This would affect all
signals from all constellations for all users, and is IMHO the only threat
worth worrying about. Because an airburst over the ocean might not be
construed as an attack on any specific nation, but it would exact a huge
economic toll on the most developed and tech-reliant nations. It must be a
tempting option for a spastic tyrant who has a nuke or two and feels backed
into a corner.

~~~
Jonnax
What about space debris? Isn't there a non zero chance that a satellite could
hit some debris and cause a chain reaction?

~~~
gingabriska
Isn't there enough redundancy in space that one sat going down means nothing
for the system

~~~
xvector
No, the issue with space debris is that we are quickly approaching the point
where a single unfortunately placed collision could chain using a sort of
exponential “shotgun effect”, destroying virtually all satellites at a given
orbit and rendering space travel impossible for decades if not centuries,
setting human space exploration back significantly as launches have to deal
with thousands of metal shards traveling at tens of thousands of mph.

See this video[1] by Kurzgesagt: “End of Space - Creating a Prison for
Humanity.”

[1]: [https://youtu.be/yS1ibDImAYU](https://youtu.be/yS1ibDImAYU)

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gchadwick
It would be interesting to know of everything that uses GPS what % of use is
purely for a very accurate synchronised time source vs uses that actually
require the location aspect.

The article states 'The researchers found that the largest benefit, valued at
$685.9 billion, came in the "telecommunications" category, including improved
reliability and bandwidth utilization for wireless networks'. I wonder if
location is actually required for these purposes or it's purely the
synchronised time source (clearly a useful thing to have when building
communication systems).

Edit: Ah the question is answered from another part of the article 'Wireless
technology continues to evolve in ways that increase its reliance on highly
precise timing, which in turn increases reliance on GPS.'

~~~
nabla9
The article mentions only GPS. Most modern receivers can use multiple systems
for redundancy; GPS, GLONASS, Galileo, BeiDou. They can also provide accurate
timing.
[https://gssc.esa.int/navipedia/index.php/Time_References_in_...](https://gssc.esa.int/navipedia/index.php/Time_References_in_GNSS)

It's not clear if they use GPS as synonym for all available GNSS or is the
study GPS only?

EDIT: I skimmed the document. The underlying assumption seems to be that US
based industries don't have or don't use multi-constellation capability.

>In looking across the many sectors and applications that require GPS’s
accuracy and precision, it becomes clear that GPS has some attributes of a
utility. The signal is a public good and service provided by the U.S.
government that enables productivity, quality, and efficiency benefits that
would not otherwise be possible. For many years, it was the only comprehensive
PNT signal available. Signals are now available from GLONASS (Russia), Galileo
(Europe), and BeiDou (China). The global marketplace means that many devices
are increasingly capable of receiving signals from multiple constellations. In
the United States, however, critical infrastructure, industries, and
applications leverage the GPS signal.

~~~
michaelt
Products like [1] consider concurrent GPS+GLONASS tracking a paid upgrade.

However, they also have 'holdover performance' allowing them to remain
accurate for several hours without a GPS signal.

[1] [https://www.microsemi.com/product-directory/carrier-grade-
nt...](https://www.microsemi.com/product-directory/carrier-grade-ntp-ptp-
grand-masters/4133-timeprovider-2700)

~~~
nabla9
Similar product from Oscilloquartz has optional GNSS kit with
GPS/GLONASS/BEIDOU/GALILEO

------
sandworm101
Note that GPS and "GPS technology" are different things. When people say "GPS"
they normally mean the US system and that is the one the article is talking
about. But there are several satellite networks that each act as a _global
positioning systems_ using "GPS technology".

We are seeing more and more devices that can access many different networks.
This is a good thing. Not only does it increase redundancy in case of a
widespread outage of one network, it diminishes any one nation's ability to
disrupt positioning. No longer can the US simply turn off or obfuscate
location data (they used to blur it. Google "GPS selective availability"). The
existence of competitor networks allows users to quickly identify and ignore
such actions.

~~~
avian
GPS is specifically the name of the US system. GNSS, Global Navigation
Satellite System, is a general name that also covers other systems.

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

~~~
myself248
NAVSTAR is specifically the name of the US system.

GNSS is the generic term.

GPS could be used to mean either, and sucks as a term.

~~~
sandworm101
If we want to be really specific, the US program is now called "NAVSTAR GPS"
and it was once manged by the "Interagency GPS Executive Board" ... so the
people running NAVSTAR still call it GPS, internally at least.

------
Maxious
"Collins Aerospace is coordinating with safety regulators and its equipment
clients after a GPS connection outage on its parts resulted in the
cancellation of hundreds of flights, especially flights on aircraft operated
by US regional carriers." [June 10 2019]
[https://www.flightglobal.com/news/articles/collins-gps-
outag...](https://www.flightglobal.com/news/articles/collins-gps-outage-
grounds-regional-flights-458819/)

------
godzillabrennus
This seems pretty low. People depend on electronic navigation almost
exclusively these days.

~~~
mikeash
My thoughts exactly. How many millions would be unable to get to work (or
stranded at work)? So many people have lost the ability to navigate without
it.

~~~
emiliobumachar
Really, is that a thing?

I'm completely unable to redo a nontrivial GPS route without the GPS after a
handful of times, but I can definitely redo routine routes. At first I'd
expect so can anyone else.

~~~
lexapro
What about all the people that started at a job recently?

~~~
Cerium
They would get a paper map? You can buy, print, or draw maps.

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brohee
I would understand if it was a full GNSS outage, must most "GPS" equipment
nowadays is multi-constellation, using as much as four (GPS, Galileo, Glonass,
BeiDou). The loss of one constellation should go undetected by most end users.

~~~
zaarn
What disaster would knock out only one constellation out of four (perfectly
one) and also go unnoticed to users?

~~~
jerf
The phrase that should strike fear into the heart of any engineer who has to
work at scale (any kind of scale, not just software): "Correlated failures". A
software bug that affects only one of them. The political possibility
mentioned elsewhere. Some computer virus never "intended" for a satellite
manages to get into one of them for some reason, most likely a very bizarre
one that nobody would have ever guessed could happen but still somehow did.
Some hardware component that turns out to fail all at the same time (more or
less), used by all of a particular constellation. Or most likely of all,
something I can't even think of to put here as an example, but still it
somehow turns out that a particular failure ends up having as a side effect
greatly increasing the chance of failures in the rest of the system despite
all the efforts to prevent that. (The "ones we can't even think of" end up
with elevated probabilities precisely because we don't think to prevent them
and thus put no engineering into preventing them.)

All of these outcomes are low probability, sure, but they are all _vastly_
higher probability than sufficient simultaneous independent failures to take
down the system. It's why despite all the incredible software engineering that
goes into Google and AWS, they still go down sometimes. Almost no conceivable
set of independent events can take those things down, but correlated failures
still can, do, and will continue to do so.

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Fnoord
If devices have other radios such as WiFi and GSM these can function as a
backup plan (I don't think BT would suffice, unless there would be P2P between
Bluetooth devices with devices who _can_ provide coordinates such as WiFi and
GSM).

For example, the first iPhone used Apple WiFi positioning; it didn't have GPS.
I still remember I had a an iPod Touch with a 3rd party GPS which worked with
the predecessor of Cydia.

Check the sources UnifiedNlp [1] can use. Quoting:

> AppleWifiNlpBackend - Uses Apple's service to resolve Wi-Fi locations. It
> has excellent coverage but the database is proprietary.

> OpenWlanMapNlpBackend - Uses OpenWlanMap.org to resolve user location but
> the NLP backend did not reach release-quality, yet. Users interested in a
> freely licensed and downloadable database for offline use should stick with
> openBmap for now - Last updated in 2015

> OpenBmapNlpBackend - Uses openBmap to resolve user location. Community-
> created, freely licensed database that can optionally be downloaded for
> offline operation. The coverage varies from country to country (it's best in
> central Europe).

> MozillaNlpBackend - Uses the Mozilla Location Service to resolve user
> location. The coverage is OK. Only the cell tower database is free.

> LocalWifiNlpBackend - Local location provider for Wi-Fi APs using on-phone
> generated database.

> LocalGSMLocationProvider - Local opencellid based location provider backend.
> Has been surpassed by LocalGSMBackend which also has an OpenCellID option -
> Last update in 2014

> LocalGSMBackend - Local location provider for GSM cells. It works offline by
> downloading freely licensed database files from Mozilla, OpenCellID, or
> lacells.db.

[1]
[https://github.com/microg/android_packages_apps_UnifiedNlp](https://github.com/microg/android_packages_apps_UnifiedNlp)

~~~
ImprovedSilence
I think a lot of cellular technologies rely on GPS on their base stations as a
timing reference. Most cellular capabilities might fall off a cliff if GPS
isn’t available.

~~~
Fnoord
Why though? If the celltower has networking (e.g. 4G), it could use NTP. The
databases with GSM just use triangulation. As long as they broadcast, the
triangulation should work.

~~~
brohee
Best case NTP is in the order of millisecond precision. Completely inadequate
for this case.

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mbostleman
I think the headline is trying to imply that this is a big number, but at 1.8%
of the world's daily GDP it doesn't seem like it. I would have thought GPS
would have a lot more impact than that.

~~~
6gvONxR4sf7o
1.8% of global GDP is huge!

~~~
mbostleman
It's 0.005% of GDP.

~~~
6gvONxR4sf7o
You said one day of GPS is 0.005% of one year GDP, but we're comparing a day
of GPS to a day of GDP, so it seems proper to say it's 1.8% like your earlier
quote, right? If we lost any length of time of GPS, it would be 1.8% of that
period's GDP?

