In what data structures are the nodes' coordinates stored internally in OSM database (64bit floating point, some long integer, something else entirely...)?
What is the minimal distance that can be recorded without two points being rounded to the same location?
For gps recordings with accuracy in meters this will hardly be a problem, but as the map gets more precise, it might become one.

Obviously the longitude precision will vary between equator and poles, but still it would be good to know what the range is.

asked 25 Aug '11, 15:52

LM_1's gravatar image

accept rate: 10%

Data Primitives says the longitude has 7 decimal positions for >−180 and <180.

4*10^7/2/180/10^7 = 0.01 meter = 1 centimeter (at the equator)

The same document says latitude has 7 decimal positions for >−90.0 and <90.0.

4*10^7/4/90/10^7 = 0.01 meter = 1 centimeter

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answered 25 Aug '11, 16:16

gnurk's gravatar image

accept rate: 15%

edited 25 Aug '11, 16:36

SomeoneElse's gravatar image

SomeoneElse ♦

There are some hints in the OSM wiki about Nodes.

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answered 25 Aug '11, 16:12

stephan75's gravatar image

accept rate: 6%

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question asked: 25 Aug '11, 15:52

question was seen: 8,741 times

last updated: 25 Aug '11, 16:36

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