Precision of Location longitude is worse when longitude is beyond 100 degrees

According to Unity Scripting Rerference, LocationInfo.longitude is a float number.http://unity3d.com/support/documentation/ScriptReference/LocationInfo-longitude.html
I guess the real value given by the GPS is then truncated to a Single-precision floating-point format within Unity.
Therefore, if I am, let say, in Manchester (Europe), my LocationInfo.longitude value would be something like -2.247926 degrees (6 decimals), meaning that I could have a horizontal location accuracy below 1 meter (although hardware accuracy will be no better than 2-5 meters).
However if I am in Los Angeles, the value for LocationInfo.longitude would be something like -118.2436 degrees (4 decimals), given that a float number cannot show more than 7 digits(including integer and decimal part). In conclusion, my Unity app using GPS would have way more than 10 meters accuracy in Los Angeles or any other longitude with a 3 digits integer part.
Can anyone confirm this issue? Am I missing something? Is there any way to avoid this?

Cheers.

 

Hi, I'm into the same issue!

Why does unity use float instead of double? I'm getting 112.123 (longitude), about 3-4 decimals. That's real bad, and this post is from 2011.....OMG.

For iOS, in iPhone_Sensors.mm, I've found these lines.
Unity casts a double into a float.

Code (CSharp):

1. UnitySetLastLocation(double timestamp,
2.                     float latitude,
3.                     float longitude,
4.                     float altitude,
5.                     float horizontalAccuracy,
6.                     float verticalAccuracy);
7.  
8. - (void)locationManager:(CLLocationManager *)manager
9.     didUpdateToLocation:(CLLocation *)newLocation
10.           fromLocation:(CLLocation *)oldLocation
11. {
12.     gLocationServiceStatus.locationStatus = kLocationServiceRunning;
13.     UnitySetLastLocation([newLocation.timestamp timeIntervalSince1970],
14.                         newLocation.coordinate.latitude,
15.                         newLocation.coordinate.longitude,
16.                         newLocation.altitude,
17.                         newLocation.horizontalAccuracy,
18.                         newLocation.verticalAccuracy);
19. }

I believe that's very very very easy to fix. Right?

 

I spent weeks trying to solve my GPS issues over a year ago and gave up. I started again this weekend determined to resolve it. My Haversine distance function was reporting a distance even when the lat/long were identical. I tore my hair out for 2 days straight, until I discovered that floats have an internal accuracy of 9 digits. If you print your lat/long with .ToString("R") you'll see the extra precision is retained from the cast to float, but standard ToString() will only show you 7 digits of accuracy.

 

actually doesn't work.

 

I believe this is to the use of lead paint at the Unity offices. Can anyone at Unity confirm?

 

Still now working.

 

Does not work in 2020 either. though what actually works in 2020 anyway??!

 

Same problems here.
Why is Unity using only float precision for Latitude and Longitude?
This problem is 8 years old and still not fixed.
Please Unity devs, it's 2021 and we still only get floating point precision for sensor data which has a way better precision internally.
That's really a shame and would be so easy to fix.

 

because some graphic cards dont accept double. Specially most phone GPUs

 

The CPUs will as a general rule though.

 

The solution, though, in short, is to use longitude.ToString("R").

Honestly, from there, a lot of what you will end up using it for will accept strings, anyway.