That is my main objection as well. This proposal is to deliberately reduce the accuracy of the data in the name of saving a few seconds of mapping time.
On April 3, 2014 12:25:46 PM CDT, "Dave F." <dave...@madasafish.com> wrote: > Mike > > We should be mapping as accurately as we can within the limitations > (gps > accuracy, aerial imagery etc) that we have. Data can always be > upgraded > when more accurate information becomes available. This proposal is a > step backwards towards inaccuracy. > > > On 02/04/2014 18:29, Mike Thompson wrote: > > > > We aim at precision/accuracy (IMHO, at least I do), > > 1) How much precision/accuracy? No real world measurement or > > recording of such measurement is exactly precise/accurate. Do you > use > > a commercial grade differential GPS when surveying? When you are > > create a way to represent a road which in reality is an arc or > curve, > > how many nodes do you use? You could increase your precision by > > adding more nodes. > > 2) In general, there is a cost to increased precision (and accuracy) > > > in terms of the survey effort, the survey equipment, the recording > > effort, and the computing resources. > > 3) At some point the value of increased precision ceases to grow, > and > > may even decline. > > > > > > > > > > > > > > On Wed, Apr 2, 2014 at 10:33 AM, Martin Koppenhoefer > > <dieterdre...@gmail.com <mailto:dieterdre...@gmail.com>> wrote: > > > > > > 2014-04-02 18:16 GMT+02:00 Mike Thompson <miketh...@gmail.com > > <mailto:miketh...@gmail.com>>: > > > > > It is also a significant loss of detail because you reduce > > the length of the bridge to 0 > > Maps are abstractions. They don't represent reality > precisely. > > > > > > > > > > We aim at precision/accuracy (IMHO, at least I do), you can > always > > create more abstracted maps from precise geodata, while the > other > > way round it is not possible. > > > > In most cases we already reduce the width of roads to 0 as > > they are not represented by areas. > > > > > > > > no, their geometric representation is a line, but their width is > > (or can be) added with a tag like width and lanes, of which the > > latter defaults to 2 (for non-links) if not added explicitly. > > > > > > The question should be whether the value of the data is > > significantly degraded if some very short bridges are > > represented as nodes. > > > > > > > > OK. Can you explain how long a "very short bridge" should be? > What > > is the benefit of this kind of mapping style? > > In this context I'd like to point out that GPS precision is not > > the limit, you do not have to take 2 waypoints at the beginning > > and end of the bridge and the result will become your bridge, > > automatically, usually you will interpret these waypoints and > will > > estimate the bridge length and represent it according to your > > estimate, so I do not think a 3 meters long bridge will result > in > > a 45 meters long zigzag in your mapping, just because you had > bad > > GPS reception under the tree canopy and made a break on the > bridge ;-) > > > > > > cheers, > > Martin > > > > _______________________________________________ > > Tagging mailing list > > Tagging@openstreetmap.org <mailto:Tagging@openstreetmap.org> > > https://lists.openstreetmap.org/listinfo/tagging > > > > > > > > > > _______________________________________________ > > Tagging mailing list > > Tagging@openstreetmap.org > > https://lists.openstreetmap.org/listinfo/tagging > > > > --- > This email is free from viruses and malware because avast! Antivirus > protection is active. > http://www.avast.com > > > ------------------------------------------------------------------------ > > _______________________________________________ > Tagging mailing list > Tagging@openstreetmap.org > https://lists.openstreetmap.org/listinfo/tagging -- John F. Eldredge -- j...@jfeldredge.com "Darkness cannot drive out darkness; only light can do that. Hate cannot drive out hate; only love can do that." Dr. Martin Luther King, Jr. _______________________________________________ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
