[countryfree]

I'm using navigation all the time when I'm traveling, which happens often. I knew that the whole GPS service could be shut off if there's a war, but I'm learning it can also be fooled. It happened in Moscow.

http://abcnews.go.com/Technology/wireStory/russians-seek-answers-central-moscow-gps-anomaly-42967498

There were people with fully functioning GPS systems, but those were telling that they were 29 kilometers from where they really were. I guess we shall learn not to be fully confident of modern electronic devices...

 

[Savage Voyageur]

I have read about this and it could happen if a war broke out. Very simple for them to do, just start with turning off the selective availability signal, and then the other signals so it would be useless.

 

[charliemeyer007]

GPS signals aren't all that strong. It is very easy to override them locally with a stronger signal. That is how they will get rid of people in self driving cars - they will have them drive right off the cliff.

You should have a printed map(s) and compass(s) and know how to use them.

 

[Pitbull_Dallas]

The government can put offsets in the GPS as well. They actually do that on the signals that commercial users use. Though almost exact, it's offset 60-100 foot in any direction. They could easily increase the offset if the need arose. That of course is not the case for the military..

That's why I always preferred Loran when I had my offshore boat. Loran could put you back on the exact same spot, time after time. A 60-100 radius is huge when your on the ocean and looking for features/objects on the bottom. But sadly, by now, Loran has been phased out..

 

[The Heretic]

The problem with turning off the higher precision modes, or spoofing GPS in general, is that there is a LOT more out there that depends on GPS precision than military equipment.

Turn off that mode or spoof it, and you will find:

1) some electrical grid equipment stops working correctly or is vulnerable to being hacked

2) Commercial and private aircraft, marine freight/fishing/etc., trucking, trains, etc., all depend on precision GPS.

3) Retail systems that use GPS for precision and accurate timing coordination.

Those are just some of the things that I can think of off the top of my head that depend on precise GPS signals.

 

[Exarmyguy]

I have never trusted my GPS devices. I always check my compass.

 

[spacemanspiff]

Now that the Russians have their GLONASS, there is not need for the US to degrade the GPS system. Think the Russians will degrade over the US to help us out?

 

[NY Min]

Those are just some of the things that I can think of off the top of my head that depend on precise GPS signals.

We've really become insanely self-destructive at the societal level, haven't we?

 

[The Heretic]

We've really become insanely self-destructive at the societal level, haven't we?

It is what it is.

The tech is improving, but it is also becoming tightly coupled such that there are weak links in the chain.

You really can't expect people to not use new and improved tech.

We just have to be aware of how fragile it can be.

 

[Chuckleberry]

The government can put offsets in the GPS as well. They actually do that on the signals that commercial users use. Though almost exact, it's offset 60-100 foot in any direction..

They quit doing that in the late 90's.

 

[DadeMurphy]

Just as an FYI, if you are using your cell phone and Google maps, GPS satellites are only one of many sensors that determine your location. Google has gone to great lengths with their in-house GIS system. Every Streetview car has instrument packs that also record:
1. Cellular information such as tower IDs, frequencies, etc...
2. Wifi radio transmissions so that you can use your Wifi antenna to locate yourself in an urban area.
3. GeoIP info on all networks they come into contact with.
4. GeoIP on every Google ChromeCast / Google connected product on the planet.

I could go on but you get the point. If you are in a populated area, or on a major highway, GPS is only one of many things your phone uses to guide you.

If you are talking about hiking / wilderness, then you are probably using something like Gaia GPS and are dependent upon GPS sats and WAAS. But my hope is that you have taken the time to know how to use a map and compass. And maybe you are like me and buy a large-format road atlas once every 2 years.

 

[2kanzam]

The government can put offsets in the GPS as well. They actually do that on the signals that commercial users use. Though almost exact, it's offset 60-100 foot in any direction. They could easily increase the offset if the need arose. That of course is not the case for the military..

Uh oh...well don't tell anyone I'm getting 1-2in accuracy in the commercial units I set up for the field analysts

 

[francessanne]

I have never trusted my GPS devices. I always check my compass.

you can also get an atlas in every convenience store across america

 

[countryfree]

Yes, I have a large road atlas, and plenty of maps. Some 3/4 years ago, I removed from the car, but I will put them back in the trunk, just in case.

Regarding navigation on my smartphone, I don't use Google, and I've switched off all mobile data. I've downloaded maps from Here when at home. It's offline navigation, but it has been working fine so far.

 

[Pitbull_Dallas]

Uh oh...well don't tell anyone I'm getting 1-2in accuracy in the commercial units I set up for the field analysts

All I can tell you is that's what they did do. I don't know if they do it now. My offshore boat had both loran and top of the line, commercial GPS. When comparing the two I found the difference and started asking questions and doing research, and that's what I found out. The GPS confirmation was actually from the .gov. Certain users, like surveyors, were "exempt" somehow..

 

[Chuckleberry]

All I can tell you is that's what they did do. I don't know if they do it now. My offshore boat had both loran and top of the line, commercial GPS. When comparing the two I found the difference and started asking questions and doing research, and that's what I found out. The GPS confirmation was actually from the .gov. Certain users, like surveyors, were "exempt" somehow..

Here's a link to a story about it. It is from 2010 celebrating 10 years of GPS for the masses, it's what helped things like geo-caching get popular.

https://www.cnet.com/news/celebrating-10-years-of-gps-for-the-masses/#!

 

[Pitbull_Dallas]

Here's a link to a story about it. It is from 2010 celebrating 10 years of GPS for the masses, it's what helped things like geo-caching get popular.

https://www.cnet.com/news/celebrating-10-years-of-gps-for-the-masses/#!

Thanks! :thumb: I knew I wasn't nuts..

They must have phased in the change, because the time period I had my boat and was on the Gulf was 1993-2003 and got the GPS in 1998. The article says it was originally about 100 yards (which i disagree with) and I said it was around 100 feet, which is still an accurate statement. I suppose over some time period they increased the accuracy, but not all at once, as the article would lead you to believe..

 

[thataway]

There are many instances of "spoof" or jamming GPS. Spoof means give an erroneous position. Jamming blocks the positing. I have had my boat GPS blocked in the close proximity of a number of naval vessels, and navy bases in the past. In July 2013 students of UT Austin, spoofed an 80 million dollar megayacht, undetected, and fooled the crew to get the vessel miles off course in the med, with gear carried in a suitcase.

However, currently there are a number of GPS chip sets which receive both the US GPS and Russian GLONASS. I have several of these devices. There are enough differences in the systems, so that if you are spoofing the GPS, the GLONASS will still be accurate, and visa versa. There are anti spoofing GPS units, and these track certain parts of the signal, so that spoofing can be detected. The military GPS is much more difficult to spoof. Jamming is much more likely--and thus several forms of navigation are always advisable.

The military version of GPS is still more accurate, by additional channels (both US and GLONASS). However, currently GPS is very accurate. Far more often maps or charts are off than GPS/GLONASS.

Pitbull Dallas, is correct that the repeatability of Loran (back in the day when selective averaging was turned on) was far better than GPS. However, GPS navigation is more accurate today. Loran used timing of terrestrial signals, and those varied by the amount of time the signal traveled over land vs over water. SA has been off since May 2000. The most recent constellation of satellites do not have the ability to do SA. No, we should not have turned off Loran, and we should be building E Loran chains as an alternate to GPS.

 

[spacemanspiff]

All I can tell you is that's what they did do. I don't know if they do it now. My offshore boat had both loran and top of the line, commercial GPS. When comparing the two I found the difference and started asking questions and doing research, and that's what I found out. The GPS confirmation was actually from the .gov. Certain users, like surveyors, were "exempt" somehow..

Now that planes are using it to land they really can't degrade it. Although the military still does in some locations. They will tell pilots about it in advance.

 

[Chuckleberry]

Thanks! :thumb: I knew I wasn't nuts..

They must have phased in the change, because the time period I had my boat and was on the Gulf was 1993-2003 and got the GPS in 1998. The article says it was originally about 100 yards (which i disagree with) and I said it was around 100 feet, which is still an accurate statement. I suppose over some time period they increased the accuracy, but not all at once, as the article would lead you to believe..

No, they switched it off altogether. IIRC using military sat. the actual variance would have been 100m with the scrambling down to 10m without. Just because you were only 100 feet off doesn't mean that was when it was being phased in, it wasn't exactly 100m off, just like it isn't always exactly 10m off now. Back then you could also do a few things like averaging where if you took a reading from the same spot several times on different days, then adjust to the center of the results and you were probably much closer to the right #'s. Also some had a deal where if you left it there for a long time it did something like that for you electronically. I haven't had one in years as I never really found them of much use (old infantryman and like maps and compass) and figured I'd sell them to get guns! :thumb: