On 05/22/2016 02:39 PM, Lars Ahlzen wrote:
On 05/21/2016 01:54 PM, Clifford Snow wrote:
TopOSM looks like a good candidate for a hack session at SOTM-US. Let me know if you are interested so I can find a room for people to meet on July 25th.

That's not a bad idea. Sounds like there's some interest in the OSM community, and I'd be happy to take a look at it again. I'd say go ahead!

Alas, I'm not going to SOTM, but put me down as someone who's interested in the project, with some 'skin in the game' already.

As I already posted privately to Clifford:

I picked up TopOSM's code for my own purposes and added quite a few twists of my own. I use the result as a basemap for several of my own projects. You can see what it looks like at https://kbk.is-a-geek.net/catskills/test3.html.

The 'catskills' in the name is something of a misnomer - it started as a Catskill Mountain project, but got out of hand and now covers most of the Eastern Seaboard. The 'test' in the name reflects that the page in question was intended largely as a demonstration viewer. I mostly use the tiles in apps on my phone.

At the moment, it's several months out of date. I've generally brought it fully up to date only a few times a year, because I've never troubled to get a pipeline going for automatic rendering with a tool such as tilestache. Given the limited area that it supports, I do all right serving static tiles. It generally takes overnight to produce them all, and warms my home office quite nicely when it's running. Clearly, I am NOT tooled up to serve it up on a large scale.

It depends on a good many publicly-available data layers with ODBL-incompatible terms. Life is full of tradeoffs. I think that a 'sanitized' version with only ODBL and US Government data wouldn't be too difficult to put together.

I'm more than willing to share the code, but it would be a bit of a nightmare to set up. I think that the best approach would be to share it with a willing apprentice (if you will) in pieces, reworking as we go to make sure that each shared piece runs for more than just me and the setup is better documented than it is now. I'm willing to put in the effort to make such a project succeed, but would find it immensely difficult without a guinea pig to try stuff out and provide ongoing feedback.

Significant public layers that I include that I believe TopOSM does not include:

(1) NLCD, the National Land Cover Database. This provides the base colour, atop which is added hillshading. For my personal map, this is not something I'm willing to live without. It's important to me, when planning an off-trail trip, to know when to expect coniferous forest (near me, this is generally dense balsam-and-spruce that slows travel to a crawl) and when to expect deciduous forest (which, by contrast, is relatively open). It also pretty much obviates the need to use NaturalEarth's 1:10million populated areas shading, which is at an inappropriately coarse scale for most of our use of it.

In order to do this, I had to replace styles describing land use/land cover/cadastre to use shading on the boundaries rather than area fills. (I think the appearance in the end is nicer in any case.) I confess to colour-blindness and would welcome a more attractive colour scheme.

(2) A fair number of FCODES from NHD (National Hydrographic Dataset) that TopOSM ignores. Ignoring these FCODEs loses, for instance, the lower Hudson River on TopOSM.

(3) The USFWS National Wetlands Inventory. Most of the marshlands that are shown on my map come from there.

There are also a few state-level data sets describing foot trails and public land boundaries in my map that I am NOT comfortable including in TopOSM without consulting with the issuing agencies. Some of the agencies are not amenable to allowing redistribution of their data, even when the law requires them to make the data available to the public. Most of those are shown on the map in magenta, and serve me as a "things to do" list when I'm thinking up ideas for a short hiking trip.




--
73 de ke9tv/2, Kevin


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