I am very cautious about any of this kind of measurement for the following reasons: 1) the results will be very difficult to standardise 2) the effort is far beyond that what a mapper can reasonably do.
If you wanted to do it properly you needed to mount a measuring device in such a way that it looks downwards to measure the reflected light, may be on some kind of arm protruding from your vehicle (bicycle in my case) and then record continuously the measurement. Now you have to consider the parameters: measurement device characteristics distance from the ground weather conditions (we would need to define "standard dry weather", because with rain you will have the problem of direct reflectosn of light sources) signal integration parameters (do you average over 10m for example?) and most likely others. Then you still have the problem of how to define the illumination quality of a stretch of cycle path. Assume you have a 100m stretch with nice illumination but there is a tiny S-bend exactly overshadowed by an evergreen tree, which produces a pitch dark spot of 10m at a dangerous point. What do you do? Put an illumination value every 5 meters or, and that's what I would do, mark the entire 100m stretch as lit=very_poor (or something similar). Constructive and realistic suggestions are welcome. Volker On 18 January 2015 at 11:34, Warin <61sundow...@gmail.com> wrote: > On 18/01/2015 5:14 PM, tagging-requ...@openstreetmap.org wrote: > > Date: Sun, 18 Jan 2015 00:14:36 -0600 > From: "John F. Eldredge" <j...@jfeldredge.com> <j...@jfeldredge.com> > To: "Tag discussion, strategy and related tools" > <tagging@openstreetmap.org> <tagging@openstreetmap.org>, Volker Schmidt > <vosc...@gmail.com> <vosc...@gmail.com> > Subject: Re: [Tagging] Tagging road illumination quality > Message-ID: > <14afbadb528.27a5.8c042f3e6e983dd0f57452e62f7f8...@jfeldredge.com> > <14afbadb528.27a5.8c042f3e6e983dd0f57452e62f7f8...@jfeldredge.com> > Content-Type: text/plain; charset="utf-8"; Format="flowed" > > You could use a light meter to measure how bright the light is. That isn't > the only factor in the suitability of the lighting, but it is objective. > > > My 'smartphone' can give a light reading -Andriod using app 'GPS Status' > in lux or foot candle. There should be others that do the same kind of > thing. Uses the camera function to determine the light from the exposure. > But 'we' will need guidance on how best to measure it. Possibly pointing it > at the ground immediately under the light for a hi reading, and anothe > midway between two lights for a low reading and take the average? Maybe a > google will turn up some ideas? The phones won't be accurate but should be > good enough for an indication. > > -- > 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." -- Martin Luther King, Jr. > > > > On January 16, 2015 11:18:33 AM Volker Schmidt <vosc...@gmail.com> > <vosc...@gmail.com> wrote: > > > > I would like to enter illumination quality for bicycle infrastructure> > (cycleways) in OSM. > > > > Any suggestions welcome>> Volker > > > > _______________________________________________ > Tagging mailing list > Tagging@openstreetmap.org > https://lists.openstreetmap.org/listinfo/tagging > >
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