Re: [OSM-talk] Own maps with hill shading and routes using mapnik
>What's wrong with Landsat / Lakewalker? >http://wiki.openstreetmap.org/index.php/JOSM/Plugins/Lakewalker If only I'd known about this a few months ago..just had a play with it and although it's not perfect, it seems to do a better job than I do for lakes that are 'clean' on the imagery - and it's certainly a lot quicker. Even for 'dirty' lakes it's a good start, which I can edit manually for the areas that it doesn't get right. Donald ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Own maps with hill shading and routes using mapnik
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Steve Hill wrote: > On Mon, 15 Sep 2008, Keith Sharp wrote: > >> I never got round to implementing anything because I discovered most of >> the bodies of water in Scotland had been mapped. > > I imagine the NPE maps cover most of the natural bodies of water. But these can vary quite a bit over 50 years... What's wrong with Landsat / Lakewalker? http://wiki.openstreetmap.org/index.php/JOSM/Plugins/Lakewalker Andy Allan wrote: > Intermediate-sized voids could be filled with image-cloning techniques > to make a synthetic landscape. It's fake, but realistic looking. I think it would be better if fake data looked fake than looked realistic, but wasn't. That way people are more likely to spot that it needs fixing, and think about fixing it. Probably using something like a weighted average of the nearest data we do have, so that large voids turn into over-smooth areas would be as good a compromise as any. > Secondly is hydrographic-model approach, which is what I believe the > GGIAR guys do, and it's how voids are traditionally filled by the > professionals (generally manually or at least labour-intensively, not > like us upstarts who just think on a fully automated, global basis ;-) > ). I thought that the point of open street map was that we have lots of labour available from volunteers. :-) Robert (Jamie) Munro -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.8 (Darwin) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkjPzU4ACgkQz+aYVHdncI00wwCgzsumaK+a6SEla8yNw3XVfzc4 v30AoNP8J2a2sIq46jjzNCegHT01knyb =/G7O -END PGP SIGNATURE- ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Own maps with hill shading and routes using mapnik
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Andy Allan wrote: > On Mon, Sep 15, 2008 at 11:08 PM, David Earl <[EMAIL PROTECTED]> wrote: >> On 15/09/2008 22:07, Donald Allwright wrote: >>> The theory is that >>> if the SRTM data include an altitude reading for the lake itself (I >>> haven't actually checked this yet!), I should be able to use an approach >>> similar to what you suggest to get a much more accurate map. The holy >>> grail would be to be able to click somewhere within a lake, and the >>> software to automatically generate a perimeter. However I suspect that >>> will be a long way off, if it ever happens. >> But will the accuracy be any better? SRTM seems to be 3 arc seconds >> outside the USA = approx 90m of latitude per pixel. > > Absolutely. I can see the idea, but if there's Yahoo or even Landsat > imagery it'll most likely be more accurate that way to get lakes. > > And don't be fooled by the contours on the cycle map - they might be > thin and look really accurate, but they are just massive > extrapolations from relatively low-resolution DEMs. Most lakes have > one or two contours running underneath them at the moment, some rivers > run uphill in some places (especially in narrow gorges) and so on. > > Cheers, > Andy > > _ Absolutely agree - I live near the hill in Essex (OK, there's 2..) & SRTM has it quite badly wrong, both height & just where the highest point is - by around a mile. Any lakes generated from that would be, well, unpredictable! Given how flat the surrounding area is I found that quite disappointing. Mark -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.6 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFIz6dMJfMmcSPNh94RAnZhAJ0X7zWZcuixPAdDRfUAyw/GqdyudQCfbIAz +Y2r5ph9gROK+UN5+Ea4Fq0= =HdNV -END PGP SIGNATURE- ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Own maps with hill shading and routes using mapnik
On Mon, 15 Sep 2008, Keith Sharp wrote: > I never got round to implementing anything because I discovered most of > the bodies of water in Scotland had been mapped. I imagine the NPE maps cover most of the natural bodies of water. - Steve xmpp:[EMAIL PROTECTED] sip:[EMAIL PROTECTED] http://www.nexusuk.org/ Servatis a periculum, servatis a maleficum - Whisper, Evanescence ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Own maps with hill shading and routes using mapnik
On Mon, Sep 15, 2008 at 11:08 PM, David Earl <[EMAIL PROTECTED]> wrote: > On 15/09/2008 22:07, Donald Allwright wrote: >> The theory is that >> if the SRTM data include an altitude reading for the lake itself (I >> haven't actually checked this yet!), I should be able to use an approach >> similar to what you suggest to get a much more accurate map. The holy >> grail would be to be able to click somewhere within a lake, and the >> software to automatically generate a perimeter. However I suspect that >> will be a long way off, if it ever happens. > > But will the accuracy be any better? SRTM seems to be 3 arc seconds > outside the USA = approx 90m of latitude per pixel. Absolutely. I can see the idea, but if there's Yahoo or even Landsat imagery it'll most likely be more accurate that way to get lakes. And don't be fooled by the contours on the cycle map - they might be thin and look really accurate, but they are just massive extrapolations from relatively low-resolution DEMs. Most lakes have one or two contours running underneath them at the moment, some rivers run uphill in some places (especially in narrow gorges) and so on. Cheers, Andy ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Own maps with hill shading and routes using mapnik
On 15/09/2008 22:07, Donald Allwright wrote: > The theory is that > if the SRTM data include an altitude reading for the lake itself (I > haven't actually checked this yet!), I should be able to use an approach > similar to what you suggest to get a much more accurate map. The holy > grail would be to be able to click somewhere within a lake, and the > software to automatically generate a perimeter. However I suspect that > will be a long way off, if it ever happens. But will the accuracy be any better? SRTM seems to be 3 arc seconds outside the USA = approx 90m of latitude per pixel. David ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Own maps with hill shading and routes using mapnik
- Original Message From: Keith Sharp <[EMAIL PROTECTED]> To: talk@openstreetmap.org Sent: Monday, 15 September, 2008 21:17:59 Subject: Re: [OSM-talk] Own maps with hill shading and routes using mapnik >I considered something similar to mapping lakes and lochs - use my GPS >with barometric altimeter to measure the elevation of the surface of the >water and then use the SRTM data to work out the contour that >corresponds to the edge of the water. Hey presto, instant loake or loch >map! I've spent quite a lot of time adding lakes in Peru, based on the yahoo imagery. However I'm aware that the imagery is not generally high resolution and hence the accuracy of this approach is poor (but better than nothing). I've just come across this page: http://wiki.openstreetmap.org/index.php/HikingBikingMaps explaining how to set up the software, and was going to have a play. The theory is that if the SRTM data include an altitude reading for the lake itself (I haven't actually checked this yet!), I should be able to use an approach similar to what you suggest to get a much more accurate map. The holy grail would be to be able to click somewhere within a lake, and the software to automatically generate a perimeter. However I suspect that will be a long way off, if it ever happens. >I never got round to implementing anything because I discovered most of >the bodies of water in Scotland had been mapped. We're quite lucky in the UK as far as having keen mappers is concerned, but when I first started doing Peru (a country I know well) there was virtually nothing on the map at all. My aim has been to get as much of the basic geographical infrastructure added as is possible using the satellite imagery (mainly rivers and lakes), as a means of encouraging local mappers to get involved. It's quite heartening to see that now there is quite a bit of mapping activity in the country. Just because your own country is covered doesn't mean the idea isn't worth pursuing!! Donald ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Own maps with hill shading and routes using mapnik
On Mon, Sep 15, 2008 at 10:17 PM, Keith Sharp <[EMAIL PROTECTED]> wrote: > I considered something similar to mapping lakes and lochs - use my GPS > with barometric altimeter to measure the elevation of the surface of the > water and then use the SRTM data to work out the contour that > corresponds to the edge of the water. Hey presto, instant loake or loch > map! > At least here, around Oslo, the SRTM data is not nearly accurate enough to do that. See, for instance, these lakes: http://www.openstreetmap.org/?lat=59.86084&lon=10.90939&zoom=15&layers=00B0FTF Regards, Gustav ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Own maps with hill shading and routes using mapnik
On Mon, 2008-09-15 at 11:24 +0100, Steve Hill wrote: > On Sun, 14 Sep 2008, Andy Allan wrote: > > > Big voids, e.g. the alps, can't just be "smoothed" over. > > I wonder if the elevation data stored in OSM for various mountain summits > might be useful for filling in small voids around the top of mountains. > It doesn't help with missing vallies though. e.g. where one side of the > mountain is missing, the missing data could be interpolated between the > known data at the edges of the void and the height of the summit. It > could go very wrong if the SRTM data doesn't closely match the OSM data > though. > > > If you have all the rivers you can constrain your filling > > algorithms to make sure the resultant landscape involves the rivers > > going downhill! So we've looked at how the river coverage in OSM > > compares to the voids, but at the moment they don't overlap so it's > > not much help to us. > > Sounds like an interested approach, and something that can probably be > automated relatively successfully, although I can't think how you would > determine the elevation of the bottom of the valley if you were missing > that data. Maybe just extrapolate from the nearby gradients that are > known. > > Whatever the method used, it sounds like there could be a lot of > corner-cases where the algorithm could produce crazy data which would > need to be trapped. :) I considered something similar to mapping lakes and lochs - use my GPS with barometric altimeter to measure the elevation of the surface of the water and then use the SRTM data to work out the contour that corresponds to the edge of the water. Hey presto, instant loake or loch map! I never got round to implementing anything because I discovered most of the bodies of water in Scotland had been mapped. Keith. ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] Own maps with hill shading and routes using mapnik
programnya kalo pake proxy gak bisa ya bos?? Pada 15 September 2008 11:07, Liko BlueX™ <[EMAIL PROTECTED]> menulis: > Sebetulnya klo mau sabar sabaran, kita akan menemui banyak sekali situs > yang membuka private foto seseorang, selain program yang sudah beredar > disini. > > misalnya: > http://manismadu.com/kampret (yang ini kayanya lagi di off in ma yang > punya) > klo ga bisa coba yang ini > > http://www.polusipositif.com/test.php > > > -- > > Di dunia ini tidak ada yang sempurna, selama itu buatan manusia, pasti ada > cacatnya! > > Account Premium RapidShare dan MegaUpload GRATIS kunjungi > http://www.freepremiumaccounts.com/?r=169168 > > Add FS ku http://profiles.friendster.com/xliko ga rugi deh ^^ > > Cuma ngisi survey ngawur 2 kata dapat $6 kunjungi > http://lists.openstreetmap.org/listinfo/talk > > -- http://igorbrejc.net ___ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
