[OSM-talk] Is *just* tracing useful?

[Andy Robinson]

David Groom wrote:
>Sent: 07 September 2007 1:15 AM
>To: talk at openstreetmap.org
>Subject: Re: [OSM-talk] Is *just* tracing useful?
>
snip
>>>
>>> In other words, I'd rather people didn't do it!
>>
snip
>>
>
>I disagree entirely.
>
>1) there are areas of the world in which we will find it very hard to get
>complete coverage unless we use Yahoo imagery.  Ok, so we may at this stage
>only have the road layout and not the names, but it's better than nothing.
>Furthermore I've mapped large areas using Yahoo imagery, and then found
>other users have gone back and annotated the roads with names etc.  These
>people did not draw the road in the first place, and so the areas would
>still be blank
>
>2) Say I've mapped an area, using GPS, add it to OSM, then look at Yahoo
>imagery and note I've missed off a few roads. Are you really suggesting I
>don't add them in just because I don't have a GPS trace for them?  I
>thought
>we were aiming for a complete map.
>
>Toms comment about deleting old segments and ways is equally applicable to
>ways and segmnets added using GPS traces, where the person adding them has
>been less than meticulous in (a) tracing accurately over a GPS track, (b)
>actually making segments into ways (c) annotating those ways correctly. The
>complaint relates to inaccurate mapping skills by the user, and not the
>tools the user is using.
>
>With careful use of the Yahoo imagery it is possible to make a very
>educated
>guess about what it is you are mapping. In my experience the majority of
>mapping time is taken by defining the route of a road / path, and whether
>this is done by tracing a GPS track, or tracing from Yahoo is irrelevant.
>Particularly with the tools in JOSM it is easy to split or combine ways, so
>if the initial mapping via Yahoo is not accurate then things can be easily
>corrected.
>
>David
>
>> I'm sure some people do it with the intention of then visiting the area,
>> so it
>> can't all be bad. But where I've been working it looks like people have
>> just
>> randomly added odd bits of roads, parks, etc.
>
>So there are random parks, so what?  Surely its better than a whole load of
>white space on the map?  I'll hold my hand up here and admit I've added
>loads of woodland from the Yahoo imagery, I'm never going to walk around
>the
>boundary of those woods, same with the parks, beaches, and the coastline
>I've corrected using Yahoo imagery.
>
>Complain about inaccurate mapping if you like, but don't single out one
>particular method for complaint!
>

Agree entirely with you on these points David, well put.

Cheers

Andy