The original use of GPS by our military is to fix a precise launch coordinate for ballistic missiles. I fully expect the Russians and the Chinese to develop jamming measures for it. They might even have it for decades, and only recently begin to use it. The fact that a truck driver can buy a jammer (no doubt from China) is proof that they had it.

Any critical system needs to have a backup source of navigation other than GPS.

I’m old enough to remember having a smartphone without built-in GPS. Google Maps back then relied on cell tower triangulation, which was only accurate enough within a couple of blocks in the city, and maybe within a mile radius in rural areas. That was around 2005-2009. Before then there was always paper map. Gotta have a Rand McNally’s Road Atlas before a road trip.

sikacz wrote: Mon Feb 01, 2021 5:30 pm Noticed I have two of the more modern ones. The aluminum cased is the WW2 one.

I still have an old "hockey puck" compass from my sailing-school days.



You just hold it to your eye and look through, lining up the target and reading the numbers.

SailDesign wrote: Mon Feb 01, 2021 5:53 pm

sikacz wrote: Mon Feb 01, 2021 5:30 pm Noticed I have two of the more modern ones. The aluminum cased is the WW2 one.

I still have an old "hockey puck" compass from my sailing-school days.

You just hold it to your eye and look through, lining up the target and reading the numbers.

Nice!

Whatever happened to moss growth on tree is north and licking finger for wind direction?? Up and down fairly easy thanks to gravity. LOL

Growing up, dad had a compass like that. Took a geo class years later that introduced me to the glory of Brunton compasses - similar set-up for survey work, with inclinometers and everything. Last time I got out to the ren fest, I saw a shop selling one in polished brass, and drooled a little.

Of course, we're a bunch of fogies old enough to measure latitude by the noontime sun, read angles off of shadows, with enough orienteering to find our position on a topo sheet down to point-blank on whatever we carry. Not everyone is. I'm open to the argument that everybody should be. Course, I've a sibling who can't tell the sun sets in the west, and this is not hyperbole.

Yes, lots of systems use backups. Your cell phone - and 911 - use triangulation from towers. Cruise missiles use accelerometers, gyros, and internal maps. ICBMs used astrogation decades back and in all likelihood still do. I dunno if any of you have ever tried running GPS where the roads have changed when your map is out of date, but it can be flipping hilarious.

Tomorrow Never Dies was a terrible movie, but I still love Jonathan Pryce. Damn, that monologue.

I'm waiting for the explanation of satellite navigation in flat-earth "theory." Calculate a stable orbital path over an irregular disk. We've got time.

CDFingers wrote: Mon Feb 01, 2021 7:53 am Topo map, compass, Boy Scout Orienteering Merit Badge booklet. Problem solved.

CDFingers

Doesn't work at sea.

The sextant does, though, if you just need to be within a nautical mile. Even a plastic training sextant would do.

Doesn't work on subs. Seem to recall a few incidents where inertial navigation and old bathymetric charts had unfortunate consequences. Or then there's the time the Brits hung up their new super-secret sub screws for all the world to see when one of the new boats got grounded before low tide.

Ylatkit wrote: Wed Feb 03, 2021 2:36 am

CDFingers wrote: Mon Feb 01, 2021 7:53 am Topo map, compass, Boy Scout Orienteering Merit Badge booklet. Problem solved.

CDFingers

Doesn't work at sea.

The sextant does, though, if you just need to be within a nautical mile. Even a plastic training sextant would do.

Sextants are surprisingly simple devices that just measure the angle of the Sun, Moon or a navigation star above the horizon.

I keep a printed road atlas for Texas and neighboring states stashed in my car just in case I am unable to connect to online maps and GPS during an emergency situation. It's kind of old, and doesn't show some of the newer local roads, but the main highways, county roads, and town locations remain the same, so it would be useful for navigating.

TxChinaman wrote: Mon Feb 22, 2021 10:46 am I keep a printed road atlas for Texas and neighboring states stashed in my car just in case I am unable to connect to online maps and GPS during an emergency situation. It's kind of old, and doesn't show some of the newer local roads, but the main highways, county roads, and town locations remain the same, so it would be useful for navigating.

Yup - an "old-fashioned" map is always helpful. I have one for New England in the car, and my phone and tablet both have Co-Pilot installed with USA and Canada maps stored locally - no interwebz required, assuming no EMP has wiped them out.

Jeebus, is Thomas Guides still being printed? Yes they are! What a great X-mas present to friends and families!

...Then again, they may only appreciate you when things turn ugly and color their view of you as a doomsday preppier for years and years.

I've road atlases for every state I've lived in the past 15 years. Extremely useful. Highly recommend. Course, nothing can compensate if you lack basic map skills.

Just think about the fact that airline pilots are allowed to just use iPads for charts, and almost all of the instrument approaches rely solely on GPS Coordinates-as do all of the new rules and equipment involving airplane separation. and they have been getting rid of the older ground-based navigational aids. I have a friend who used to be the navigator on a refueling tanker- but they don’t have those now.

As for maps-I still recall fondly the trips to the AAA office to have them put together a TripTic whenever we travelled anywhere farther away. I should at least get a backup map I suppose.