OpenStreetMap Forum

Alec Teal

Member

Registered: 2009-08-06

Posts: 1

What about current map inaccuracies

I live in a very rural area, the maps for my area are currently inaccurate (i use them with my phone GPS softwere) like roads are off by 20 meters or so, so when i walk my dog up one way and down another, its often quite far off.

worst i have had so far is about 80 meters and some roads are not charted; so how does one (me) remove segments of track already there to put a more accurate counterpart in,

Alec

Ldp

Member

From: NL - Zeeland

Registered: 2008-07-22

Posts: 820

Re: What about current map inaccuracies

You can move the nodes of the misaligned ways so they align more or less with your own collected gps track. No need to remove the road and create a new one. We also get to keep the history of the road, if you move it.

Be careful though, walking and accurate tracking don't always combine well. If you walk those roads more often, it might be a good idea to compare your tracks, and take an average to align the road in OSM.

BennieD

Member

Registered: 2009-05-22

Posts: 10

Re: What about current map inaccuracies

I want to stress what Ldp said. Don't change a way that is already created, without verifying your own measurements . In the end you just end up changing it back and forth! (happened to me).

Check the accuracy of your GPS at the time of measurement: signal strength, most devices gives an indication of the accuracy. Best I can get on my Nuvi200W is 4 meters on an exceptionaly clear day. Sometimes it is as far out as 20 -30 meters in bad conditions.

Things that influence accuracy: Cloud cover
                                              Tree cover
                                              Time of day? it seems to me that the satelites moves around- at mornings I   
                                                                 struggle to get a fix, in the afternoons it happens faster & better.
                                                                 Maybe the old hands can confirm / deny?
                                              Make sure you get a decent fix standing still, before you start tracking.
                                              Compare tracks with tracks made by different devices, different weather,         
                                              different times of day.

happy tracking