Re: [OSM-talk] Old GPS data
On Tue, Jul 28, 2009 at 5:22 AM, Aleksejs Mjaliksli...@keeper.lv wrote: Does OSM invalidates GPS data after some time? Otherwise, roads continuously changes and after we will have a big cloud of points that don't make any sense. No, it doesn't. GPX tracks stay where they are forever and continue being served by the GPS API. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Old GPS data
On Tue, Jul 28, 2009 at 09:21, Ævar Arnfjörð Bjarmasonava...@gmail.com wrote: Does OSM invalidates GPS data after some time? Otherwise, roads continuously changes and after we will have a big cloud of points that don't make any sense. No, it doesn't. GPX tracks stay where they are forever and continue being served by the GPS API. anyway this is something that we might need to consider in the future. GPS are becoming more precise. older tracks are, on a general basis, less precise than actual ones. and road modifications will become more apparent as we progress. -- -S ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Old GPS data
Simone Cortesi wrote: On Tue, Jul 28, 2009 at 09:21, Ævar Arnfjörð Bjarmasonava...@gmail.com wrote: Does OSM invalidates GPS data after some time? Otherwise, roads continuously changes and after we will have a big cloud of points that don't make any sense. No, it doesn't. GPX tracks stay where they are forever and continue being served by the GPS API. anyway this is something that we might need to consider in the future. GPS are becoming more precise. older tracks are, on a general basis, less precise than actual ones. and road modifications will become more apparent as we progress. But there is no way to determine if a particular GPS track is outdated. Sure, you can look at the map and say I don't see a physical road for this track, but how would you identify GPS points of a track that is invalid? Especialy for the anonymous tracks? Maarten ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Old GPS data
On Tue, 28 Jul 2009, Simone Cortesi wrote: Does OSM invalidates GPS data after some time? Otherwise, roads continuously changes and after we will have a big cloud of points that don't make any sense. No, it doesn't. GPX tracks stay where they are forever and continue being served by the GPS API. anyway this is something that we might need to consider in the future. GPS are becoming more precise. older tracks are, on a general basis, less precise than actual ones. and road modifications will become more apparent as we progress. please , don't drop data for many areas we are lucky to have one trace and it may be a year or more before another mapper goes back there consider having access to older data in separate sets if there is concern about using old gps tracks, just don't drop any because it is old (like some of us) ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Old GPS data
--- On Tue, 28/7/09, Maarten Deen md...@xs4all.nl wrote: But there is no way to determine if a particular GPS track is outdated. Sure, you can look at the map and say I don't see a physical road for this track, but how would you identify GPS points of a track that is invalid? Especialy for the anonymous tracks? date they were added to the system? ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Old GPS data
--- On Tue, 28/7/09, Liz ed...@billiau.net wrote: please , don't drop data for many areas we are lucky to have one trace and it may be a year or more before another mapper goes back there consider having access to older data in separate sets if there is concern about using old gps tracks, just don't drop any because it is old (like some of us) Maybe the best option is to let people stipulate how many traces they want and then download them in reverse order based on data submitted. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Old GPS data
--- On Tue, 28/7/09, Simone Cortesi sim...@cortesi.com wrote: GPS are becoming more precise. older tracks are, on a general basis, You can't make assumptions of the quality of the data based simply on how recently it was added, someone might be using an old piece of GPS kit they were given as a hand me down. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Old GPS data
This doesn't make sense to me. At least there should be a timestamp of gpx-files which tells us when they've been uploaded so that one could filter them a la show me gpx-files not older than 3 years ! Roman On Tue, Jul 28, 2009 at 5:22 AM, Aleksejs Mjaliksli...@keeper.lv wrote: Does OSM invalidates GPS data after some time? Otherwise, roads continuously changes and after we will have a big cloud of points that don't make any sense. No, it doesn't. GPX tracks stay where they are forever and continue being served by the GPS API. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Old GPS data
On Tue, Jul 28, 2009 at 09:59, John Smithdelta_foxt...@yahoo.com wrote: --- On Tue, 28/7/09, Simone Cortesi sim...@cortesi.com wrote: GPS are becoming more precise. older tracks are, on a general basis, You can't make assumptions of the quality of the data based simply on how recently it was added, someone might be using an old piece of GPS kit they were given as a hand me down. I'm talking in the long run. Not something to be done in the coming moths. Still we are just 5 years old. And not many roads did change shape in this short period of time. -- -S ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Old GPS data
On Tue, Jul 28, 2009 at 09:58, John Smithdelta_foxt...@yahoo.com wrote: consider having access to older data in separate sets if there is concern about using old gps tracks, just don't drop any because it is old (like some of us) Maybe the best option is to let people stipulate how many traces they want and then download them in reverse order based on data submitted. and/or depending on density of GPSdata in that area. we still have HDOP and VDOP data that (if present) is not being used to spit out accuracy information. -S ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Old GPS data
Hello ! One think I think it can be useful is a tool for editing all our old trace : - easy to download all our trace - easy to remove unprecise segment (in some old my trace I have some segment who is 50 m wrong !) - easy to simplify them - easy to re-upload modified trace ! I think that a tool like it can be greatly improve the quality of traces. CU Stéphane Liz a écrit : On Tue, 28 Jul 2009, Simone Cortesi wrote: Does OSM invalidates GPS data after some time? Otherwise, roads continuously changes and after we will have a big cloud of points that don't make any sense. No, it doesn't. GPX tracks stay where they are forever and continue being served by the GPS API. anyway this is something that we might need to consider in the future. GPS are becoming more precise. older tracks are, on a general basis, less precise than actual ones. and road modifications will become more apparent as we progress. please , don't drop data for many areas we are lucky to have one trace and it may be a year or more before another mapper goes back there consider having access to older data in separate sets if there is concern about using old gps tracks, just don't drop any because it is old (like some of us) ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk signature.asc Description: OpenPGP digital signature ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Old GPS data
--- On Tue, 28/7/09, Simone Cortesi sim...@cortesi.com wrote: I'm talking in the long run. Not something to be done in the coming moths. Still we are just 5 years old. And not many roads did change shape in this short period of time. Some areas have lots of road duplication construction within 5 years of time. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Old GPS data
John Smith wrote: --- On Tue, 28/7/09, Maarten Deen md...@xs4all.nl wrote: But there is no way to determine if a particular GPS track is outdated. Sure, you can look at the map and say I don't see a physical road for this track, but how would you identify GPS points of a track that is invalid? Especialy for the anonymous tracks? date they were added to the system? That is not indicative. A road could remain unchanged for the last 100 years or could have been demolished last year. What would be the expiration time of a track? And would you be prepared to lose correct GPS data to do this? Regards, Maarten ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Old GPS data
--- On Tue, 28/7/09, Maarten Deen md...@xs4all.nl wrote: That is not indicative. A road could remain unchanged for the last 100 years or could have been demolished last year. What would be the expiration time of a track? And would you be prepared to lose correct GPS data to do this? Also as Liz put, some areas have very few traces so removing based on age is generally a bad idea, where as software specifying fewer tracks to show only the most recent might be the best way to handle it. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
[OSM-talk] Old GPS Data
Sorry to break the threading,
Maybe it's an idea to allow users to specify an area where traces are outdated?
So when a junction is reconstructed a local user can place a bounding
box over that junction and all GPS points in that box are marked as
outdated (or deleted, or whatever). Maybe some extra safety needs to
be made by only allowing users active in the specific area to do this,
or only users who upload traces.
I can think of a few places in my immediate area where the older
('wrong') traces have the upper hand.
Rene.
Maarten Deen:
Simone Cortesi wrote:
On Tue, Jul 28, 2009 at 09:21, ?var Arnfj?r? Bjarmasonava...@gmail.com
wrote:
Does OSM invalidates GPS data after some time? Otherwise, roads
continuously changes and after we will have a big cloud of points that
don't make any sense.
No, it doesn't. GPX tracks stay where they are forever and continue
being served by the GPS API.
anyway this is something that we might need to consider in the future.
GPS are becoming more precise. older tracks are, on a general basis,
less precise than actual ones. and road modifications will become more
apparent as we progress.
But there is no way to determine if a particular GPS track is outdated. Sure,
you can look at the map and say I don't see a physical road for this track,
but how would you identify GPS points of a track that is invalid? Especialy
for the anonymous tracks?
Maarten
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Re: [OSM-talk] Old GPS Data
--- On Tue, 28/7/09, René Affourtit raffour...@gmail.com wrote:
Maybe it's an idea to allow users to specify an area where
traces are outdated?
So when a junction is reconstructed a local user can place
a bounding
box over that junction and all GPS points in that box are
marked as
outdated (or deleted, or whatever). Maybe some extra safety
needs to
be made by only allowing users active in the specific area
to do this,
or only users who upload traces.
I can think of a few places in my immediate area where the
older
('wrong') traces have the upper hand.
I don't know what the right solution is, I've seen people mark ways in OSM to
show what is old ways along side new ways and I can only assume they did this
to prevent old traces from being used to draw ways.
However getting into who should and shouldn't remove GPS traces is going to be
a very interesting topic in and off itself which I don't have a solution to
either.
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Re: [OSM-talk] Old GPS data
Also, and I've already posted here about that a while ago, it would really help if hdop, and eventually vdop, wasn't lost in the anonymization process. This is an important data when tracing, but unless you know who published the track and you can download the source, you don't have access to that information which is really a pity. And even if it implies a downtime while the database schema is upgraded, it would really be worth it. Yann Le 28 juil. 09 à 10:28, John Smith a écrit : --- On Tue, 28/7/09, Maarten Deen md...@xs4all.nl wrote: That is not indicative. A road could remain unchanged for the last 100 years or could have been demolished last year. What would be the expiration time of a track? And would you be prepared to lose correct GPS data to do this? Also as Liz put, some areas have very few traces so removing based on age is generally a bad idea, where as software specifying fewer tracks to show only the most recent might be the best way to handle it. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
[OSM-talk] Old GPS data
Hello! I am currently looking at GPS collected by OSM colleges here at Riga. I see there is data about temporary bridge built during road works and after de-mounted. Does OSM invalidates GPS data after some time? Otherwise, roads continuously changes and after we will have a big cloud of points that don't make any sense. Aleksejs ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
