how accurate are the GPS

[Jeep or Tacoma]

on say a Lenovo Samsung or similar android platform?

 

[AaronK]

In my experience, within a few feet

Sent from my KFFOWI using Tapatalk

 

[1leglance]

Remember this above all else......It is all a lie
There is built error to civilian gps otherwise it would be too easy to use it for nefarious purposes.
Now that said in a 4wd you are good with the standard 30ft +/- error the math gives you.
Also know that really all you are getting is a dot, and that means we have to talk about the quality of the map you use. If it is old data then you can have issues.

Also remember the system needs to see 3 satellites for position and a 4th for elevation. So it is important to give your device as much clear sky as possible when you install, thus putting your device in a cup holder or low dash mount can cause issues.

Then we get into adding GLONASS to give you USA & Russian satellites

Honestly modern stuff suffers more from user error (mounting locations) and crappy maps than anything else.

I run a netbook with a BT353 usb gps puck and OziExplorer (old USGS maps) and Delorme Topo in the USA and then add an old Garmin PC program running a Mecxican GPS suite for Baja.
OpenStreet Maps is another good resource out of the USA as you get lots of end user updated data.

 

[e60ral]

Remember this above all else......It is all a lie
There is built error to civilian gps otherwise it would be too easy to use it for nefarious purposes.
Now that said in a 4wd you are good with the standard 30ft +/- error the math gives you.
Also know that really all you are getting is a dot, and that means we have to talk about the quality of the map you use. If it is old data then you can have issues.

Also remember the system needs to see 3 satellites for position and a 4th for elevation. So it is important to give your device as much clear sky as possible when you install, thus putting your device in a cup holder or low dash mount can cause issues.

Then we get into adding GLONASS to give you USA & Russian satellites

Honestly modern stuff suffers more from user error (mounting locations) and crappy maps than anything else.

I run a netbook with a BT353 usb gps puck and OziExplorer (old USGS maps) and Delorme Topo in the USA and then add an old Garmin PC program running a Mecxican GPS suite for Baja.
OpenStreet Maps is another good resource out of the USA as you get lots of end user updated data.

it's not true anymore about civilian GPS. What you are thinking of was called "Selective Availiability" but it was turned off in 2000. The only limits now on GPS is that you can't use it going over 1,200 mph or higher than 60k ft. GPS by itself is only accurate to a few meters, anything more accurate than that is using some kind of differentiating or augmenting system. Even a cheap tablet or phone will be able to give you accuracy within a few feet. WAAS is the augmentation system developed for aviation that is available now on some phones and tablets, surveyors get survey-grade accuracy by using RTK with a network of stationary GPS receivers that are used to correct the moving GPS signal by acting as a reference.

The quality of the GPS receiver and sampling rates will vary widely among tablets, if you are planning on using one as a GPS its something you need to look into before buying.

I am using an Asus Zenpad 8 which uses GPS and Glonass (don't think it has WAAS though) and am very satisfied with the GPS performance.

 

[DaveNay]

...surveyors get survey-grade accuracy by using RTK with a network of stationary GPS receivers that are used to correct the moving GPS signal by acting as a reference.

My wife's brother is a heavy equipment operator, and the GPS accuracy they have available is remarkable. They install GPS receivers on the left and right of the bulldozer blade, and they can control the elevation of the blade to within about a 1/4" (6mm).

 

[kmlacroix]

The GPS in my truck's Nav unit sucks. I use my iPad (when off-road) or iPhone for normal driving. I also have a Delorme InReach. I use the iPad and Gaia to track my route, and paper maps to figure out where I am. Modern GPS units are usually very accurate.

 

[fisher205]

My wife's brother is a heavy equipment operator, and the GPS accuracy they have available is remarkable. They install GPS receivers on the left and right of the bulldozer blade, and they can control the elevation of the blade to within about a 1/4" (6mm).

That rig is used with a stationary base from a known point so that it can differentiate and correct the gps on the machine. Base cost for that system would be around $20,000. I would guess the one on the machine shown would have automatic controls and the cost of that system would be around $150,000.

 

[DaveNay]

That rig is used with a stationary base from a known point so that it can differentiate and correct the gps on the machine. Base cost for that system would be around $20,000. I would guess the one on the machine shown would have automatic controls and the cost of that system would be around $150,000.

Absolutely. I didn't mean to imply that they were using "raw" GPS. The differential signal utilizing known survey points is essential.

 

[ChadHahn]

I don't know if it's because It's also using the cellphone signal but my iPhone knows if I'm on the sidewalk or in the street when I'm using it's mapping program to go somewhere. If I'm on the sidewalk it will give me walking times but if I get in the street it'll give me driving times.

Chad

 

[RobRed]

I don't know if it's because It's also using the cellphone signal but my iPhone knows if I'm on the sidewalk or in the street when I'm using it's mapping program to go somewhere. If I'm on the sidewalk it will give me walking times but if I get in the street it'll give me driving times.

Chad

Yes your phone uses Assisted-GPS (AGPS). The cellular network cell sites locations are precisely known and provide additional reference to augment the raw GPS data. Very much like the heavy equipment discussed above but on a much larger scale.

 

[rayra]

Those are all various implementations of what is generally known as differential GPS. Devices that use things like WAAS are combining data from both the GPS satellites and ground-based transmitters to further refine their accuracy. With a clear sky, several satellites and WAAS you can typicalyl get 7-13' accuracy out of small handheld hiking GPS units.

My dash-mounted Samsung Tab 3 Lite android wifi tablet just uses standard GPS and it is perfectly adequate for offline map navigation and crosschecking my speedometer speed.
Their cellular devices use what they call AGPS, Assisted GPS, which is taking locatoin data from teh cell network, a form of differential GPS.

 

[Kerensky97]

GPS are accurate enough now that the most inaccurate data you're probable going to get is from the map your coordinates are laid over; not al maps are created equal and even classic USGS surveyed maps had errors and estimations (and the new ones since 2000 are crap). 20ft left or right from GPS errors shouldn't be so confusing that you don't know where you are on a good topo map unless you're doing something like Geocaching.

 

[Hopeless Diamond]

Elevation always seems off though. I shouldn't say always, the head unit in my truck (Kenwood/Garmin) is usually pretty close if not spot on as I go over marked mountain passes. But around town near sea level it is usually quite far off. I seemingly spend most of my day below sea level, told me once we were -138 while riding a ferry, don't think the tide was out that far...

 

[PhulesAU]

Don't depend on roadside signs for accuracy.

 

[Christophe Noel]

Within a few feet in most cases. I mountain bike almost daily with a GPS and notice my tracks from day to day are seldom off by more than 6-10 feet in any one spot.

Samsung phone is what I use.