Clarification about the term "GPS Shutdown"

[Juergen Nieveler]

I don't know. Ask the NSA.

They won't know either - Pentagon won't tell them

If it works for the legitimate users, it will work for the spies and
their clients.

It's not as easy as you might think. The spy will have to get the
information out. If he wants to avoid being caught, he has to make sure
that he doesn't always rush out immediately after receiving the new
codes - that might draw suspicion. He'll also wants to drop the codes
off in a secure place, where they get retrieved hours later by somebody
"just strolling along", who'll also try not to go there every day at
the same time.

The legitimate users can get their keys at the same time every day
without drawing suspicion - they've got a big advantage.


Juergen Nieveler

 

[Juergen Nieveler]

It takes hours to shut it down, and hours to start it back up (all the
satellites have to pass over the right spots).

Now you contradict yourself. If "each satellite covers an entire
hemisphere", each satellite also can be seen by anybody in that
hemisphere, and thus each satelite can be reprogrammed by an antenna in
that hemisphere. Pentagon has access to ground stations around the
world (CONUS, Europe, Australia), so it would be trivial for them to
reprogramm the satellites - they don't have to pass a single point on
earth for this.

Many new technologies don't work without GPS--GPS made them possible.
There is no fallback plan for these technologies, so if you depend on
them (and you can't avoid depending on them forever), you must have
GPS.

This is your wakeup call, then. Don't depend on GPS, it might not
always be available.


Juergen Nieveler

 

[JetCaptain]

There have been a number of comments about 2 aspects:
1) Terrorists would get the military receiver codes, so therefor would have
GPS available and
2) You can't shut down the civilian system without running everyone out of
business.

A few additional comments from my perspective:

If a terrorist picks a GPS off the body of a dead US soldier before
recovery, we need to reduce the probability that the GPS can be used against
us. If a single individual or small group of terrorists is operating
somewhat independently of any well organized world "headquarters" (which
seems to be the case currently), it is less likely that the organization
will have the assests in place to acquire the necessary codes on a timely
ongoing basis. Having changing codes does not absolutely prevent use, but
it makes it far less likely to occur. So that makes use of civilian units
more likely.

Nobody said that we would shut down the civilian system for days - no scope
of time was mentioned in the report of the administration remarks I read.
It may well be that the intent is to be able to shut off the civilian system
for only as long as a dire emergency exists. For example, a terrorist is
using GPS to guide a plane to target. This GPS outage might last an hour or
two at most. The reason the administration wishes to create such a policy
statement is to recognize the importance of GPS and the consequences of a
GPS outage. Granted, there might be significant consequences to any length
of outage, but surveyors going out of business would not be one of them.
For those applications (timing related) where any loss of GPS signal would
be locally catastrophic, I am quite sure the operators of those systems have
a backup plan or already have their bags packed. While GPS is very much a
utility, it is also a very new one and no reasonable person with a mission
critical need for specific timeing data would use GPS (or any other system)
without a fallback plan.

My main point is that the debate on this group seems to be conducted at the
extremes - "we will shut down the system forever and have to navigate by the
stars" or "the willing accomplice of the terrorist empire will prove
military codes instantly, so what's the point in shutting down the civilian
side only?" I suggest that this policy is not about absolute risk
containment. It does reduce the liklihood that our own assets can be used
against us. Having such a policy in place may discourage terrorists from
using civilian GPS since they know there exists a contingency plan to
minimize the effectiveness of their attack. There will be no period of
uncertainty where someone in Washington pauses in confusion with a finger on
the "off" switch. So as a terrorist, perhaps you pass up GPS and look for a
better way to procede. Given that they are so bent on being martyrs,
delivering a "dirty nuke" via pickup truck to downtown USA would probably be
a reasonable and more likely alternative. We learned that often there is not
time to dispatch a fighter plane if there is a highjacking and someone has
to be consulted. We need a plan in place real time to deal with fast
unfolding dire emergencies. Yes there are economic and social risks
involved in executing the plan, but the expectation is that the consequences
of not doing it would be far worse.

Finally I hear a fresh voice of reason. Despite what others may think, if I
lose GPS, I will not pilot my craft into the side of a mountain. Nor will I
lose the ability to land safely. There is nothing in the forseeable future
to make me think otherwise.

This whole topic has become nothing more than a "straw dog" based more on
politics than reality.

I have yet to see a company or business named that requires the use of GPS
signals to keep their clocks synchronized to within nanoseconds. Hell, my
cell phone time is synchronized with the cellular provider and the last
time I checked (1 minute ago) it is a full 2 minutes off. Anyone else using
Cingular? Check it yourself.

I have seen no convincing evidence that the selective shutting down of the
GPS signals will have a dire effect on any major business. If such a
business exists, please state the company name here so that I can be sure
it is not in my stock portfolio. I would not invest in a company that has
such poor management that a back up plan is not in place.

I well remeber the dire predictions of the year 2000. Books were written,
people panicked and stocked up with food and supplies, gun sales went up,
and on and on. Huge profits were made by the purveyors of gloom and doom.
Shall we now start a new frenzy?

So the EU will begin their own program which is equivalent to the US GPS
system. God Bless them. Nothing wrong with that. Let's hope that our
European friends that use GPS for a hobby are not forced to pay a heavy
usage tax for the privelege of using the new system. I don't think that the
casual hobbyist geocacher, jogger, cycler, or automobile user will be
willing to pay the potentially heavy cost just to avoid the remote
possibility that the US system is off for a period. Of course, there is the
real possibility that receivers of the US GPS signals could be outlawed in
those countries thereby forcing them to "pay to play".

Is one so naive as to believe that our nations governments are so far apart
that we would not be in close collaboration if the systems were to be used
by an enemy of any State or Nation? Do you believe that the US would not
shut down their GPS system if there was knowledge it was going to be used
in a terror attack in another State or Nation? Do you believe the opposite
would be true?

Quite frankly, the plan as outlined by the Federal government promises
improvements to the existing GPS. That is to be welcomed. I have yet to see
anything rationally presented where there would be a dire national
emergency if it were selectively shut down for a period of time.

Hint, give me the Company names that are so dependant on GPS timing or
navigational ability that they would cease to function if the GPS signals
were shut down for some period so that I can divest them from my portfolio.

As I said, this whole thing is a "straw dog", politically motivated, and
would not be worthy of serious discussion except for the technical
knowledge being shared.

 

[JetCaptain]

There have been a number of comments about 2 aspects:
1) Terrorists would get the military receiver codes, so therefor would have
GPS available and
2) You can't shut down the civilian system without running everyone out of
business.

A few additional comments from my perspective:

If a terrorist picks a GPS off the body of a dead US soldier before
recovery, we need to reduce the probability that the GPS can be used against
us. If a single individual or small group of terrorists is operating
somewhat independently of any well organized world "headquarters" (which
seems to be the case currently), it is less likely that the organization
will have the assests in place to acquire the necessary codes on a timely
ongoing basis. Having changing codes does not absolutely prevent use, but
it makes it far less likely to occur. So that makes use of civilian units
more likely.

Nobody said that we would shut down the civilian system for days - no scope
of time was mentioned in the report of the administration remarks I read.
It may well be that the intent is to be able to shut off the civilian system
for only as long as a dire emergency exists. For example, a terrorist is
using GPS to guide a plane to target. This GPS outage might last an hour or
two at most. The reason the administration wishes to create such a policy
statement is to recognize the importance of GPS and the consequences of a
GPS outage. Granted, there might be significant consequences to any length
of outage, but surveyors going out of business would not be one of them.
For those applications (timing related) where any loss of GPS signal would
be locally catastrophic, I am quite sure the operators of those systems have
a backup plan or already have their bags packed. While GPS is very much a
utility, it is also a very new one and no reasonable person with a mission
critical need for specific timeing data would use GPS (or any other system)
without a fallback plan.

My main point is that the debate on this group seems to be conducted at the
extremes - "we will shut down the system forever and have to navigate by the
stars" or "the willing accomplice of the terrorist empire will prove
military codes instantly, so what's the point in shutting down the civilian
side only?" I suggest that this policy is not about absolute risk
containment. It does reduce the liklihood that our own assets can be used
against us. Having such a policy in place may discourage terrorists from
using civilian GPS since they know there exists a contingency plan to
minimize the effectiveness of their attack. There will be no period of
uncertainty where someone in Washington pauses in confusion with a finger on
the "off" switch. So as a terrorist, perhaps you pass up GPS and look for a
better way to procede. Given that they are so bent on being martyrs,
delivering a "dirty nuke" via pickup truck to downtown USA would probably be
a reasonable and more likely alternative. We learned that often there is not
time to dispatch a fighter plane if there is a highjacking and someone has
to be consulted. We need a plan in place real time to deal with fast
unfolding dire emergencies. Yes there are economic and social risks
involved in executing the plan, but the expectation is that the consequences
of not doing it would be far worse.

Finally I hear a fresh voice of reason. Despite what others may think, if I
lose GPS, I will not pilot my craft into the side of a mountain. Nor will I
lose the ability to land safely. There is nothing in the forseeable future
to make me think otherwise.

This whole topic has become nothing more than a "straw dog" based more on
politics than reality.

I have yet to see a company or business named that requires the use of GPS
signals to keep their clocks synchronized to within nanoseconds. Hell, my
cell phone time is synchronized with the cellular provider and the last
time I checked (1 minute ago) it is a full 2 minutes off. Anyone else using
Cingular? Check it yourself.

I have seen no convincing evidence that the selective shutting down of the
GPS signals will have a dire effect on any major business. If such a
business exists, please state the company name here so that I can be sure
it is not in my stock portfolio. I would not invest in a company that has
such poor management that a back up plan is not in place.

I well remeber the dire predictions of the year 2000. Books were written,
people panicked and stocked up with food and supplies, gun sales went up,
and on and on. Huge profits were made by the purveyors of gloom and doom.
Shall we now start a new frenzy?

So the EU will begin their own program which is equivalent to the US GPS
system. God Bless them. Nothing wrong with that. Let's hope that our
European friends that use GPS for a hobby are not forced to pay a heavy
usage tax for the privelege of using the new system. I don't think that the
casual hobbyist geocacher, jogger, cycler, or automobile user will be
willing to pay the potentially heavy cost just to avoid the remote
possibility that the US system is off for a period. Of course, there is the
real possibility that receivers of the US GPS signals could be outlawed in
those countries thereby forcing them to "pay to play".

Is one so naive as to believe that our nations governments are so far apart
that we would not be in close collaboration if the systems were to be used
by an enemy of any State or Nation? Do you believe that the US would not
shut down their GPS system if there was knowledge it was going to be used
in a terror attack in another State or Nation? Do you believe the opposite
would be true?

Quite frankly, the plan as outlined by the Federal government promises
improvements to the existing GPS. That is to be welcomed. I have yet to see
anything rationally presented where there would be a dire national
emergency if it were selectively shut down for a period of time.

Hint, give me the Company names that are so dependant on GPS timing or
navigational ability that they would cease to function if the GPS signals
were shut down for some period so that I can divest them from my portfolio.

As I said, this whole thing is a "straw dog", politically motivated, and
would not be worthy of serious discussion except for the technical
knowledge being shared.

 

[JetCaptain]

There have been a number of comments about 2 aspects:
1) Terrorists would get the military receiver codes, so therefor would have
GPS available and
2) You can't shut down the civilian system without running everyone out of
business.

A few additional comments from my perspective:

If a terrorist picks a GPS off the body of a dead US soldier before
recovery, we need to reduce the probability that the GPS can be used against
us. If a single individual or small group of terrorists is operating
somewhat independently of any well organized world "headquarters" (which
seems to be the case currently), it is less likely that the organization
will have the assests in place to acquire the necessary codes on a timely
ongoing basis. Having changing codes does not absolutely prevent use, but
it makes it far less likely to occur. So that makes use of civilian units
more likely.

Nobody said that we would shut down the civilian system for days - no scope
of time was mentioned in the report of the administration remarks I read.
It may well be that the intent is to be able to shut off the civilian system
for only as long as a dire emergency exists. For example, a terrorist is
using GPS to guide a plane to target. This GPS outage might last an hour or
two at most. The reason the administration wishes to create such a policy
statement is to recognize the importance of GPS and the consequences of a
GPS outage. Granted, there might be significant consequences to any length
of outage, but surveyors going out of business would not be one of them.
For those applications (timing related) where any loss of GPS signal would
be locally catastrophic, I am quite sure the operators of those systems have
a backup plan or already have their bags packed. While GPS is very much a
utility, it is also a very new one and no reasonable person with a mission
critical need for specific timeing data would use GPS (or any other system)
without a fallback plan.

My main point is that the debate on this group seems to be conducted at the
extremes - "we will shut down the system forever and have to navigate by the
stars" or "the willing accomplice of the terrorist empire will prove
military codes instantly, so what's the point in shutting down the civilian
side only?" I suggest that this policy is not about absolute risk
containment. It does reduce the liklihood that our own assets can be used
against us. Having such a policy in place may discourage terrorists from
using civilian GPS since they know there exists a contingency plan to
minimize the effectiveness of their attack. There will be no period of
uncertainty where someone in Washington pauses in confusion with a finger on
the "off" switch. So as a terrorist, perhaps you pass up GPS and look for a
better way to procede. Given that they are so bent on being martyrs,
delivering a "dirty nuke" via pickup truck to downtown USA would probably be
a reasonable and more likely alternative. We learned that often there is not
time to dispatch a fighter plane if there is a highjacking and someone has
to be consulted. We need a plan in place real time to deal with fast
unfolding dire emergencies. Yes there are economic and social risks
involved in executing the plan, but the expectation is that the consequences
of not doing it would be far worse.

Finally I hear a fresh voice of reason. Despite what others may think, if I
lose GPS, I will not pilot my craft into the side of a mountain. Nor will I
lose the ability to land safely. There is nothing in the forseeable future
to make me think otherwise.

This whole topic has become nothing more than a "straw dog" based more on
politics than reality.

I have yet to see a company or business named that requires the use of GPS
signals to keep their clocks synchronized to within nanoseconds. Hell, my
cell phone time is synchronized with the cellular provider and the last
time I checked (1 minute ago) it is a full 2 minutes off. Anyone else using
Cingular? Check it yourself.

I have seen no convincing evidence that the selective shutting down of the
GPS signals will have a dire effect on any major business. If such a
business exists, please state the company name here so that I can be sure
it is not in my stock portfolio. I would not invest in a company that has
such poor management that a back up plan is not in place.

I well remeber the dire predictions of the year 2000. Books were written,
people panicked and stocked up with food and supplies, gun sales went up,
and on and on. Huge profits were made by the purveyors of gloom and doom.
Shall we now start a new frenzy?

So the EU will begin their own program which is equivalent to the US GPS
system. God Bless them. Nothing wrong with that. Let's hope that our
European friends that use GPS for a hobby are not forced to pay a heavy
usage tax for the privelege of using the new system. I don't think that the
casual hobbyist geocacher, jogger, cycler, or automobile user will be
willing to pay the potentially heavy cost just to avoid the remote
possibility that the US system is off for a period. Of course, there is the
real possibility that receivers of the US GPS signals could be outlawed in
those countries thereby forcing them to "pay to play".

Is one so naive as to believe that our nations governments are so far apart
that we would not be in close collaboration if the systems were to be used
by an enemy of any State or Nation? Do you believe that the US would not
shut down their GPS system if there was knowledge it was going to be used
in a terror attack in another State or Nation? Do you believe the opposite
would be true?

Quite frankly, the plan as outlined by the Federal government promises
improvements to the existing GPS. That is to be welcomed. I have yet to see
anything rationally presented where there would be a dire national
emergency if it were selectively shut down for a period of time.

Hint, give me the Company names that are so dependant on GPS timing or
navigational ability that they would cease to function if the GPS signals
were shut down for some period so that I can divest them from my portfolio.

As I said, this whole thing is a "straw dog", politically motivated, and
would not be worthy of serious discussion except for the technical
knowledge being shared.

 

[High Sierra]

SNIP

This is your wakeup call, then. Don't depend on GPS, it might not
always be available.


Juergen Nieveler

Right! Always carry a compass.

 

[Juergen Nieveler]

The reason phased transmission isn't used is that each satellite's
footprint is almost a whol hemisphere.
http://www.edu-observatory.org/gps/GPS_BeamPattern.jpg

Each satellite covers almost a whole hemisphere, but each satellite has
a different footprint. As long as no more than 2 active satellites are
visible over the horizon, GPS is useless in that particular area. 100
miles away the horizon will be different, and there might be more
active satellites visible.


Juergen Nieveler

 

[Juergen Nieveler]

I'd be surprised that the codes are not administrated remotely. Some
higher level of authority can selectively re-key all the other receivers
to shut out any lost equipments.

Not really likely. You'd want to keep equipment as simple as possible -
being able to administer them remotely means that you have to have
2-way communications for every military GPS receiver. Might be doable
for the IVIS systems, but impossible for the handheld gear.

And it's not as if loosing a military GPS receiver would be that
critical, anyway: Given a 24 hour code cycle, the lost receiver would
remain usefull for 24 hours at the most. That's not really much - you
can't just say "Oh, I'll capture a receiver and stage a
counter-offensive within the next few hours using it". And you won't be
able to retrieve the codes from the receiver and enter them into your
missile guidance system, because such systems will be made tamper-proof
- as soon as you turn them off to dismantle them, they'll loose the
keys and are turned into junk.


Juergen Nieveler

 

[Juergen Nieveler]

Code dissemination is classified.

No surprise, really - but I'm sure that they don't send the codes out
weeks in advance, and I'm willing to bet that it's closer to 24 hours
in advance... precisely for the reason I keep stating: To make it more
difficult for a spy to send out the codes in time to be usefull.


Juergen Nieveler

 

[Sam Wormley]

Now you contradict yourself. If "each satellite covers an entire
hemisphere", each satellite also can be seen by anybody in that
hemisphere, and thus each satelite can be reprogrammed by an antenna in
that hemisphere.

What makes you think so?

 

[Sam Wormley]

I have seen no convincing evidence that the selective shutting down of the
GPS signals will have a dire effect on any major business. If such a
business exists, please state the company name here so that I can be sure
it is not in my stock portfolio. I would not invest in a company that has
such poor management that a back up plan is not in place.

precision agriculture on a global scale
precision guided ordinance
precision mapping of utility poles, oil wells
tracking of wildlife
automobile navigation systems

more: http://www.google.com/search?q="requiring+GPS"

 

[Alan Browne]

None of these serves any purpose if you lose a critical part of your
infrastructure.

You're too polarized in your thinking and you haven't named a single thing that
is so GPS dependant that it will fail totally. It is acceptable, for example,
in a communications network that its capacity (datarate) falls in the event of a
component failure. There is no excuse for it to fail entirely.

If the priority is safety, why is anyone discussing turning off GPS in
the first place? One can scarcely imagine anything more unsafe.

The point, which you are slipping and sliding to avoid recognition, is that you
should not design anything that is susceptible to a single point failure where
safety is involved.

 

[Sam Wormley]

Each satellite covers almost a whole hemisphere, but each satellite has
a different footprint. As long as no more than 2 active satellites are
visible over the horizon, GPS is useless in that particular area. 100
miles away the horizon will be different, and there might be more
active satellites visible.

Turn off all the satellites that a GPS receiver can see and then
calculate the numbers seen at all point on the earth and the DOPs
at those locations and you will find that the damage is not nearly
as *localized* as you might think. Do the calculations.

 

[Sam Wormley]

Hint, give me the Company names that are so dependant on GPS timing or
navigational ability that they would cease to function if the GPS signals
were shut down for some period so that I can divest them from my portfolio.

precision agriculture on a global scale
precision guided ordinance
precision mapping of utility poles, oil wells
tracking of wildlife
automobile navigation systems

more: http://www.google.com/search?q="requiring+GPS"

 

[Sam Wormley]

Hint, give me the Company names that are so dependant on GPS timing or
navigational ability that they would cease to function if the GPS signals
were shut down for some period so that I can divest them from my portfolio.

precision agriculture on a global scale
precision guided ordinance
precision mapping of utility poles, oil wells
tracking of wildlife
automobile navigation systems

more: http://www.google.com/search?q="requiring+GPS"

 

[Alan Browne]

There have been a number of comments about 2 aspects:
1) Terrorists would get the military receiver codes, so therefor would have
GPS available and

They won't. Even if they did, keys are valid for 7 days. If the next 8 weeks
worth of keys were stolen, then they would be re-issued. Control of these keys
is extremely tight. No less tight than other COMSEC material.

2) You can't shut down the civilian system without running everyone out of
business.

A very few businesses may be severely afected. Many partially affected. Most,
not affected at all. The economy will not come crashing down as many expect.
Last summer's NE power failure was huge economically but life and business go
on. A GPS outtage of 24 hours would have far less impact.

A few additional comments from my perspective:

If a terrorist picks a GPS off the body of a dead US soldier before
recovery, we need to reduce the probability that the GPS can be used against
us. If a single individual or small group of terrorists is operating

He better do it within whatever time remains for the keys in that receiver which
would be no more than 7 to 14 days.

Nobody said that we would shut down the civilian system for days - no scope
of time was mentioned in the report of the administration remarks I read.
It may well be that the intent is to be able to shut off the civilian system
for only as long as a dire emergency exists. For example, a terrorist is
Yes.

My main point is that the debate on this group seems to be conducted at the
extremes - "we will shut down the system forever and have to navigate by the
stars" or "the willing accomplice of the terrorist empire will prove
military codes instantly, so what's the point in shutting down the civilian
side only?" I suggest that this policy is not about absolute risk
containment. It does reduce the liklihood that our own assets can be used
against us. Having such a policy in place may discourage terrorists from

Right on. Further, I beleive that most systems employing GPS have adequate
capability to work without GPS for periods ranging from minutes to weeks to
years. The designer/operators of those systems must make sure they know the
limitations whan GPS is not available and that the system can indeed work.
Planning, implementing, testing and training are always required.

using civilian GPS since they know there exists a contingency plan to
minimize the effectiveness of their attack. There will be no period of
uncertainty where someone in Washington pauses in confusion with a finger on
the "off" switch. So as a terrorist, perhaps you pass up GPS and look for a
better way to procede. Given that they are so bent on being martyrs,
delivering a "dirty nuke" via pickup truck to downtown USA would probably be
a reasonable and more likely alternative. We learned that often there is not
time to dispatch a fighter plane if there is a highjacking and someone has
to be consulted. We need a plan in place real time to deal with fast
unfolding dire emergencies. Yes there are economic and social risks
involved in executing the plan, but the expectation is that the consequences
of not doing it would be far worse.

Very well put.

Cheers,
Alan

 

[Sam Wormley]

You can supply your own electricity - quite easy, just buy a diesel
generator. Not as easy for GPS...

In a lifeboat? On an airplane? On horseback?

 

[Alan Browne]

Pieter Litchfield writes:




How would he use it against us? Just plug it into the "GPS receiver"
slot in his waiting cruise missile?

It won't happen that way. Do't worry about it. If terrorists (or a warring
nation) use GPS, it will be C/A.

It takes hours to shut it down, and hours to start it back up (all the
satellites have to pass over the right spots).

No. The satellite nav packages keep on running. From block II (or is it IIR),
the satellites have to maintain spec. accuracy without updates for 30 (or is it
60) days. So if you shut off the transmitter, the nav keeps on going. The
Alamanc data in your receiver is good (by design) for 30 days, but in reality is
sufficient for much longer to aid acquisition.

Even the older sats, if they stopped transmitting, wouldn't have moved so far
from their orbital paths that their unupdated ephemeris would be totally
unuasable after many days. An unnoticeable degree of degradation for almost all
receivers except surveyors and the people who update GPS. And that would be
resolved within days after return to service.

The system cannot be shut off that quickly.

In a heartbeat.

Long enough to guide a few dozen civilian aircraft into the side of a
mountain. With casualties like that, who needs a terrorist?

No aircraft depends (legally) on GPS alone for navigation. VOR's, LORAN-C,
NDB's, etc. are still doing fine, and if you have INS you don't really care at all.

People dying on aircraft might well be one of them, however.
BZZZZTTTTTT.




Many new technologies don't work without GPS--GPS made them possible.
There is no fallback plan for these technologies, so if you depend on
them (and you can't avoid depending on them forever), you must have GPS.

You have yet to name one.

The extreme is in suggesting that it's a practical idea at all. Today
it makes no more sense than turning off all the electricity in the
country. You don't shut off public utilities just because some nut has
a bomb.

You do shut off gas. If it was usuggested that shutting off GPS would prevent
another Sept. 11 type disaster, I don't think there would be more than a minutes
hesitation. You don't really need to shut it off, you just need to skew the C/A
(via S/A) so badly that no receiver would generate a valid solution. After the
emergeny, normal reception would be available in about 4 hours.

The off switch takes hours to flip, so it doesn't matter.

In the case that an attack was taking place on the US, most sats helping a
receiver in the US could be imediately commanded to have a huge S/A skew making
receivers come up with unusable solutions.

 

[Pieter Litchfield]

precision agriculture on a global scale
precision guided ordinance
precision mapping of utility poles, oil wells
tracking of wildlife
automobile navigation systems

I don't think that there is a proposal out there that reasonably anticipates
shutting down civilian GPS for months. About the only thing on the list
that requires immediate GPS support is precision guided ordinance, and I'm
guessing the military isn't depending on the civilian signals for this one
anyway.

I am somewhat familiar with "precision agriculture", and frankly some of it
is a tractor salesmans best tool for maintaining margin. A year without it
would not substantially impact the world's food supply.

All the wildlife would be happy to avoid those annoying wildlife
biologists - in fact the cancellation of wildlife studies could result in
more federal dollars for reading programs or midnight basketball or
something really important like health care for the elderly.

As for auto navigation systems, the world will survive quite nicely for a
few days or weeks without them. maybe people would be "forced" to reacquire
the fine old art of map and compass navigation.

In short, there's nothing on this list that would be substantially impacted
by a short pause in GPS signals. As the minutes turn into hours or weeks or
months, the impacts might become measurable.

 

[Sam Wormley]

I don't think that there is a proposal out there that reasonably anticipates
shutting down civilian GPS for months. About the only thing on the list
that requires immediate GPS support is precision guided ordinance, and I'm
guessing the military isn't depending on the civilian signals for this one
anyway.

When you start adding up the man-hours of productivity lost, potential lives
lost, data lost, equipment and networks lost... this could easily be higher
than billions of dollars (US) per day! This is really an economic issue.