GPS hacking is here

[Jammer]

GPS is hard to spoof over long distances especially if trying to produce plausible results for a moving receiver.

It is relatively easy to spoof over very short distances for a receiver that remains stationary, so people who want to spoof the court's ankle bracelet or the boss's tattletale have it easy.

Seems unlikely that this would become a problem at sea.

[Paul L]

. The inertial guidance systems are accurate to 150 hours of operation and must be realigned by other surface-dependent navigational systems (GPS, radio, radar, satellite)

https://science.howstuffworks.com/tr...submarine4.htm
Not a definitive site, but plausible. I can image them floating a small Garmin Handheld GPS to the surface on a tether to get an updated fix every few days.

[Adelie]

Originally Posted by Pete7

I think Phil suggested a sextant with a camera that can recognise a star and therefore calculate a position when you point it at a couple in quick succession.



The US Navy have gone back to teaching the sextant to its Nav officers and ratings, wonder why



Pete

With a modern digital camera you don’t need the sextant, you need to have pre-calibrated to camera and it’s optics to determine the number of pixels per degree and if there is any variation in the value across the field of view.

If you want an in depth discussion of this the NavList folks have been working on this for a number of years.


Regarding CelNav at the USNA, they started teaching it to the officer candidates again so they could effectively manage the rating that actually do the sights and reductions. I do not believe that the Navy ever stopped training the ratings or stopped stocking ships with the appropriate equipment.
On the other hand I expect that underway practice has been minimal to non-existent up until recently. The USNA is reviving its program with the help of the Merchant Marine Academy which never disbanded its program.

I don’t know where the USAF is with this.

[SV THIRD DAY]

Chemtrails.....

[Paul L]

Originally Posted by Jammer

GPS is hard to spoof over long distances especially if trying to produce plausible results for a moving receiver.

It is relatively easy to spoof over very short distances for a receiver that remains stationary, so people who want to spoof the court's ankle bracelet or the boss's tattletale have it easy.

Seems unlikely that this would become a problem at sea.

At sea I think you would be more likely to run into a possibly large area where GPS was temporarily disabled by the US military. Say if you were in the western Pacific and the military thought that rocket(s) might be fired toward Guam.

[arsenelupiga]

there is considerable chance of nuclear global conflict in 2018.

If this happens all these satellites will likely become dust or useless piece of junk orbiting earth.

Satellite photos saved on HD from number of sites best insurance in my opinion.

Paper charts are inaccurate in close quarters.

[Adelie]

Originally Posted by arsenelupiga

. . .

Satellite photos saved on HD from number of sites best insurance in my opinion.



Paper charts are inaccurate in close quarters.

On what do you base this opinion?

[arsenelupiga]

Originally Posted by Adelie

On what do you base this opinion?

three events that happened in 2017 in south pacific, which is my area of interest

1. grounding 1 - pilot guy grounds his cat, trying to take shortcut. Turns out navionics not updated on mobile. so software charts error. discussed on cf to death.

2. grounding 2 - another grounding, another unhappy family, also discussed on cf. reef misplaced fro 3NM on chartds, cant be bothered to find details

3. grounding 3 - one that has not been discussed on CF, even by seaslug guy that does not like seawind cats.
See here in minerv a reef

British couple marooned in shark-infested Pacific | Daily Mail Online

english guy has 200k NM seamiles and crying like baby because he did not zoom down to 12NM and missed the reef. BTW- big plus for Privilege cats - float nicely.

naaa, thats not reliable enough for me.

happy new year 2018, and I hope my predictions are wrong.

[Wotname]

Originally Posted by arsenelupiga

three events that happened in 2017 in south pacific, which is my area of interest

1. grounding 1 - pilot guy grounds his cat, trying to take shortcut. Turns out navionics not updated on mobile. so software charts error. discussed on cf to death.

2. grounding 2 - another grounding, another unhappy family, also discussed on cf. reef misplaced fro 3NM on chartds, cant be bothered to find details

3. grounding 3 - one that has not been discussed on CF, even by seaslug guy that does not like seawind cats.
See here in minerv a reef

British couple marooned in shark-infested Pacific | Daily Mail Online

english guy has 200k NM seamiles and crying like baby because he did not zoom down to 12NM and missed the reef. BTW- big plus for Privilege cats - float nicely.

naaa, thats not reliable enough for me.

happy new year 2018, and I hope my predictions are wrong.

These are hardly examples of paper charts (except maybe #2 - I don't recall the details ATM).

[arsenelupiga]

Originally Posted by Wotname

These are hardly examples of paper charts (except maybe #2 - I don't recall the details ATM).

i trust 6 mths old free satellite photo more than much typically older paper chart . Soft copies of charts are more up to date and correction can be released much faster if one has internet.

gps receivers coordinates may be 'moved' for whatever reason and only reliable way to navigate is to map picture objects to objects one can see, and then navigate safely entry to coral reef, for example.

[Adelie]

Originally Posted by arsenelupiga

three events that happened in 2017 in south pacific, which is my area of interest



1. grounding 1 - pilot guy grounds his cat, trying to take shortcut. Turns out navionics not updated on mobile. so software charts error. discussed on cf to death.



2. grounding 2 - another grounding, another unhappy family, also discussed on cf. reef misplaced fro 3NM on chartds, cant be bothered to find details



3. grounding 3 - one that has not been discussed on CF, even by seaslug guy that does not like seawind cats.

See here in minerv a reef



British couple marooned in shark-infested Pacific | Daily Mail Online



english guy has 200k NM seamiles and crying like baby because he did not zoom down to 12NM and missed the reef. BTW- big plus for Privilege cats - float nicely.



naaa, thats not reliable enough for me.



happy new year 2018, and I hope my predictions are wrong.

So you think that a couple of incidents of improperly used electronic charts and 1 accident related to a cartography mistake in an electronic chart are reason enough to forswear PAPER charts?

And instead rely on satellite photos which won’t show all the hazards?

[arsenelupiga]

Originally Posted by Adelie

So you think that a couple of incidents of improperly used electronic charts and 1 accident related to a cartography mistake in an electronic chart are reason enough to forswear PAPER charts?

And instead rely on satellite photos which won’t show all the hazards?

nothing shows all current hazards. In places where one does not know quality of charts and/or GPS accuracy unreliable, photos are true asset that I will not leave home without.

[hellosailor]

Sorry to bring up the point (I'm lying, I'm not sorry at all) but the topic here is the intentional manipulation and introduction of error into the GPS system.

Not whether users have foolishly misused it, by failing to zoom in, or failing to learn that GPS positions conform to a different earth than what cartographers used to use. And that hundred year old paper charts SHOULD NOT be expected to match GPS mapping. If a user doesn't know what "ground conformation" means, sure, they're going to sail onto rocks or drive off a ferry dock.

That's not a system problem, that's all user error.

What is being done to the GPS system now, with inexpensive hardware, is that the instruments themselves are being made potentially unreliable, despite being "properly" used.

Whether that affected any of those groundings? Horses, not zebras.

[CarlF]

In studying the cases of GPS jamming, this just doesn’t seem to be a offshore problem worth worrying about.

But if it does happen, one of these solutions should promptly get your GPS signal back

A) You have sailed your pleasure boat into a war zone (or war practice zone) Who cares about pinpoint navigation? Run before someone shoots at you!

B) Sail away from any nearby boats as quickly as you can. GPS jamming equipment has a very short range so it’s on a boat in sight. You can bet the FAA has already gotten a report from some plane. Guys with large guns (both civilian and military) are likely on their way. So again - run before someone shoots at you!

[a64pilot]

Jamming and spoofing are completely different.
Jamming is easy, it’s child’s play, all you need is to know the frequency or even close to it and just transmit noise is all.
Spoofing is completely different and way more sophisticated, and while it’s possible, it’s not likely done by much less than a Government with a lot of resources, especially Military GPS.
I am certain that subs do in fact spend considerable time on just inertial Nav, have done so for a very long time. Heck even the completely unsophisticated INU’s on an Apache helicopter, I could fly around for 30 min doing maneuvers and it would come back to a spot within just a few feet, and a helicopter is way more tough on an INU than tons of Submarine, and I’m sure the sub’s INU’s are way more sophisticated. The A model Apache’s Nav system was pure INU dampened by a Doppler Radar.
On edit, I’d be surprised if the subs don’t have very detailed sonar charts and may use that to help navigate? Like a Cruise missile navigates on a terrain map?