How accurate is GPS???

brannsiu

Distinguished
Apr 20, 2013
146
1
18,635
I am really shocked to first learn that a picture taken with a mobile device could implicitly record the GPS location in the file properties , if I do not intentionally remove it.

I am really shocked because I 've taken many photos and I never knew about scrubbing the data in the properties and I 've shared some of the photos in dangerous sites with dangerous people.

it's no use crying over spilled milk...

But I really wish to know the bottom line...how accurate could a GPS value point to a location? I am mostly taking the photos in my building room where I am in a crowded city.
Could intentional people find out my exact address with the GPS value?



In addition

How to check location with the GPS value??

Here's an example of my GPS value I see from my pictures (I've changed the value but not the format),

12; 26; 3.9620000000022412
123; 52; 66.018500000005518
Height 33

How can I use the format to find out the GPS location??

Thank you!!~~!!!!


 

ulises314

Commendable
May 25, 2016
8
0
1,520
It's about two meters, so yeah they will find your address if you shared the pic that was taken with your cellphone. Use open camera (android) to take pics without the gps tag or better, use post processing software to share only the image, without meta data.

<Edited by Moderator>
 

brannsiu

Distinguished
Apr 20, 2013
146
1
18,635
To ulises314

Please don't make this negative assumption. I don't do anything illegal. And I am never interested in child porn!!!!!! I have faith in my religion!!!!!


It's very difficult and meaningless to explain the reasons. However, sharing any photos with my exact location is not my will.

BTW, any recommended freeware to one click scrub off the image data??

 
Hey,
The basic values you would have are likely:

a) longitude
b) latitude
c) altitude
d) time

The first three give you the position in space, the last the time. Thus you know the space-time event.

There are lots of programs that support the GPS format so if looking at the pictures in one of those programs they will point to wherever it was taken.

BTW, it's called "geotagging":
http://www.bhphotovideo.com/c/find/newsLetter/GPS-Geotagging.jsp
 
Ever use GPS software for driving, you type in the address and it takes you there. In the early days, there was an intentional 150' "error" put in on purpose ... I was once driving over a bridge and it reported my position as 95' below sea level.

Now its about 2m for the usually handheld equipment (So not only will it take you to the right house but the right room) and 2 cm for survey grade instruments.
 

brannsiu

Distinguished
Apr 20, 2013
146
1
18,635
Now I've disabled the location service in the setting of my Android device. Is now mind free enough???

In addition to GPS location value, anything very personal that a picture could implicitly record???
 

ulises314

Commendable
May 25, 2016
8
0
1,520


Easiest way would be taking and screenshot of the image and share only the screenshot, never the image, that would hit the resolution, I use the gimp to get rid off metadata but has a bit of a step learning curve.