[OSM-newbies] GPS Trace ownership
jewen at shaw.ca
Wed Oct 15 03:28:04 BST 2008
On Tue, Oct 14, 2008 at 4:25 PM, Mark Williams
<mark.666 at blueyonder.co.uk> wrote:
> The idea is that you use the GPS traces as a background or guide, to
> draw the ways over; so the actual ID of the trace is rather irrelevant.
Okay, can I get you to trace out a couple thousand kms of highway for me?
> Whilst there are tools that allow a trace to be converted to a ways,
> they aren't good unless you have a long fast drive over a single road to
> trace, because they jitter about & aren't that consistent.
That's exactly what I want to do. In this part of the world, the best
way I have found to collect road data is to drive the road, convert
the track to locked ways, cut the track into small segments that
Potlatch will convert, tie them all back together, and finally connect
any intersections that might exist.
When you are mapping thousands of kms of highway at a time, making use
of the tools available only makes sense. I spent 2 days driving 1200
kms, but only needed to spend 1/2 an hour of extra time turning that
GPS data into a highway. I have no desire to spend a week of my time
tracing over a GPS track that describes the highway very well.
Here's a short section of the Liard Highway that I converted from my
GPS track into an OSM way in seconds, and edited into a final product
within 3 minutes.
Which came from a GPS track collected during a 6 hour drive.
Here's part of what I traced out over the course of 4 days driving,
>$500 worth of fuel, and about 1 hour of editing time.
Tracing out 2400 kms of highway by hand would take much longer than an
hour. If I couldn't convert my traces to ways automatically, I would
not be taking part in the OSM project.
While I try to put descriptive tags on my GPS traces so that people
can find the raw data, I don't put every conceivable tag on the trace.
Someone looking for the GPS trace that goes through Sikanni Chief
won't find it tagged with either of these words. As a matter of fact I
didn't even label it with Highway_97 or Highway_77... It could be
difficult to find out which trace is running through the area.
In a similar fashion, I find myself wanting to know the source of the
GPS trace that runs through an area where I would like to fix up the
Allan Rasmussen has traced out Highway 93 by hand from low resolution
imagery, but someone has driven the highway and uploaded a GPS trace
which describes the true course of the highway in greater detail and
accuracy. If I could find the GPS trace, I could convert it into a
locked way, and from there create a better description of highway 93
for inclusion in the OSM database.
I have tried just about every key word that I can think of to describe
the area where the trace runs, but it is difficult to know what
keywords if any are associated with the trace. If there were a way to
ask for any GPS traces that intersect a bounding box, or the current
viewing area, this would give one the opportunity to finish the job
that someone else started. When viewing the OSM data online, I can
simply open a Data Overlay, and get information about the nodes and
ways that exist in the current view, including the usernames of those
who have worked on the data. If this could also identify the GPS
traces in the view, or have a similar capability in Potlatch, it would
fit the bill perfectly.
I don't see why I should have to spend hundreds of dollars in fuel as
well as countless hours of time driving routes that have already been
driven, logged, and uploaded to the OSM database.
Here's where you can find one end of a GPS trace that appears to cover
many kms of roadways that I would like to upgrade from rough traces to
actual representations of highways.
I do not see how privacy concerns can be an issue either. The
information collected has been voluntarily uploaded and inserted into
the OSM database by the user, only the final step of converting the
raw data into OSM ways has not been completed.
There are hundreds if not thousands of kms of GPS traces that I have
found in BC that are not yet converted to ways. I would gladly spend
the few minutes per way to convert and add these traces to the
database, but I am not willing to waste countless hours tracing this
existing data by hand.
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