GPS hacking is here

[a64pilot]

Originally Posted by Nightcrawler

Often wondered about this, after the USGov revealed their drones were vulnerable. Not a year later this happened. Eyes and mates watching ahead for us, at all times.

The long and short of it is I believe the RQ-170 doesn’t use GPS but rather a digital map and inertial Nav, which is I believe very similar to a Cruise missile.
However, I’d bet they jammed the data link or spoofed it, but that is just a wild guess

[a64pilot]

Originally Posted by buzzstar

Maybe, maybe not. Either way, few civilians, if any, cruise with military GPS units.

A Military GPS uses a completely different frequency, the civilian GPS uses the C code of the satellites, a military GPS uses the P code.
Plus there is a secure fill that the military GPS needs to properly function, and of course this fill changes regularly.
I believe the GPS system was conceived and funded as a Military system, but of course was very early on allowed for civilian use, possibly so that the US system would be the standard before other systems were launched is my guess.
So the US taxpayer has funded navigation for the world for years.

[patprice]

Originally Posted by boat_alexandra

Soon they will start hiding gps jammers on their enemy's vessel. The device could activate only in adverse weather. It's time to get a decent sextant, because celestial can't be jammed, or can it?

My sextant gets badly "jammed" when I cannot see the celestial target. A common occurrence.

[Bill Seal]

Nuclear submarines navigate for months at a time using only inertial systems.

[seandepagnier]

Originally Posted by boatman61

I believe the USA is experimenting with airborne cloud creation..

Aren't there IR cameras that can "see" stars or at least the sun through the clouds somehow?

[Pete7]

Originally Posted by Bill Seal

Nuclear submarines navigate for months at a time using only inertial systems.

Plus a paper chart and a pencil.

Originally Posted by boat_alexandra

Aren't there IR cameras that can "see" stars or at least the sun through the clouds somehow?

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

[Paul L]

Originally Posted by boat_alexandra

Aren't there IR cameras that can "see" stars or at least the sun through the clouds somehow?

Moisture absorbs IR and blocks the imaging.

[CarinaPDX]

One summer on the south coast of England my Navtex popped up a Notice that the Royal Navy would be experimenting with jamming GPS offshore and plan on not having it. For the great majority of cruisers without Navtex that would have come as a big surprise...

Greg

[alansmith]

Mother Nature has been jamming celestial navigation since it first began. Clouds!!!

[Wotname]

Originally Posted by alansmith

Mother Nature has been jamming celestial navigation since it first began. Clouds!!!

As well as some selective dithering - wave motion...

[robregje]

Dear Alexandra,

And other sailors who fear a cloud-conspiracy. Good old mother N. gave the medieval sailers already an (overcast Gps) answer for that.
Called sunstone https://en.wikipedia.org/wiki/Sunstone_(medieval)

[Jim Cate]

Hmm... The US Naval Acadamy has renewed instruction in celestial nav! Yes, this seems to be true, but do any of you believe that on their ships at sea folks are doing celestial routinely to check up on their GPS positions? I kinda doubt it, and I kinda doubt if I will get the sextant out and start up my old celestial practices.

Worry about GPS spoofing from a yotties POV is paranoia IMO... better things to worry about.

Jim

[a64pilot]

No, I feel sure the Academy has resurrected celestial Nav as a sort of history lesson, to give the kids an appreciation of what their fore fathers had to do, and how now understanding the skills required, just how great their accomplishments were.
In truth as a Retired Military Officer I can attest that if you really, really needed celestial Nav to be accurate, you wouldn’t have an Officer do it as an additional duty, you would have an enlisted person do it as their primary reason for existence. Then you would have an accurate fix, as that was their primary job.
Now if you really wanted a Professional who was the most technically and tactically proficient possible, then you would have a Warrant Officer do it

Think about it, does an Officer helm the “Boat”, or does he give an enlisted person a course to steer?

[Adelie]

Originally Posted by boat_alexandra

Soon they will start hiding gps jammers on their enemy's vessel. The device could activate only in adverse weather. It's time to get a decent sextant, because celestial can't be jammed, or can it?

If you are seriously interested in CelNav I can help get you started.

[Adelie]

Originally Posted by Bill Seal

Nuclear submarines navigate for months at a time using only inertial systems.

I do not believe that is accurate. INS like other forms of DR navigation (yes, it is a form of DR) drifts over time.

I found a drift value of 0.6nm/hr but it was unclear whether that was for a sub or an aircraft. Let’s assume a sub’s INS drifts 0.6nm/day. I don’t see the USNavy being happy with the accumulated error past 1 week (4.2nm error) maybe 2 weeks at the outside (8.4nm error). At intervals the sub will need to determine position to an outside reference and reset/update the INS position.

There are any number potential sources for external updates CelNav, GPS, comparison of local bottom profile to bathymetric charts.