问题
I have some data with GPS coordinates with upto 9 decimal points. Example of this is
39.1234567891 -75.1987654321
I need to process this data to get a context of where the person is. But I want to treat the coordinates encompassed within 100m as a single location for simplicity. Can anyone point to any reference that would indicate how many decimal points I should round off to get to this level of accuracy.
回答1:
9 digits is too detailed for any but a long term geodetic app.
6 digits is in centimeter range, and usually the most accurate what makes sense for a GPS device.
At equator 4 digits after decimal point is 11.11m.
3 digits are 111.11m
(Calculated by earthCircumference / 360.0)
This would normally result a raster, but since Earth is a sphere, the distance between two longitudes shrinks when moving away from the equator (with a factor of cos(latitude)) the distance between two latitudes does not change.
来源：https://stackoverflow.com/questions/15528255/gps-coordinates-accuracy