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Welcome!
Board: OpenStreetMap
Jun 2, 2014 5:00am
Welcome to the AQ OpenStreetMap board! Any subject relating to OpenStreetMap is suitable for discussion. If you're not familiar with OSM, start by checking it out:

http://www.openstreetmap.org

Tip: Before saving that link as a bookmark, zoom in on the map to your own region. Then when you save the bookmark, it'll save that location as well.

Membership at OSM is free. You can, if you wish, use the same trailname you use here on AQ -- or you can use a different one for anonymity.

Editing OSM maps is fun and gives a feeling of accomplishment, but the editors (there are several) are powerful and take some getting used to. On this board we can discuss tips and tricks we've learned to make editing easier.

Note that editing roads on OSM is a snap. When you click on "edit" it brings up the existing OSM map with a satellite view for a background. Often it becomes obvious that the roads are shown in the wrong place! In just a few minutes you can shift them around, moving one "node" at a time, until they correspond with reality. Everyone who uses a map based on OSM maps (and it seems to be most maps these days!) will thank you.

Editing foot trails is more problematic because they often are not visible in the satellite photos. For these situations, the thing to do is to actually go out and walk the trail while carrying a GPS device that will record a "trace" of where you've gone. Upload that trace to OSM and use it to create a map of that trail.

Don't have a GPS device? Well, if you have a smartphone, you probably do. For Android devices, you can install a free app called Vespucci that enables you to edit OSM maps from your smartphone and it also features a GPS trace function. Turn it on and go for a hike! If you've gotta hike the trail to find a letterbox anyway, you might as well!
Offer to Edit Maps
Board: OpenStreetMap
Jun 2, 2014 5:59am
Thread
One other thing I hope this board will bring about is people offering to edit maps for those who don't feel up to tackling it themselves but would like something fixed. Right now, I'm making that offer: If you zoomed in on the map on OpenStreetMap.org to your own neighborhood and realized that it's messed up, just send me an e-mail with the URL of the map of your neighborhood and I'll take a look at it. If I can see the roads on the satellite photo, I can move them around. Remember, though, that I can't see road NAMES on the satellite photo, so if you want road names changed you'll need to describe which roads should be named what.
Re: Offer to Edit Maps
Board: OpenStreetMap
Reply to: #850827 by Kirbert
Jun 2, 2014 6:07am
Thread
Is there a way on OSM to put trail in different colors? This might be useful in places where there are more than one trail with different colors. I'm trying it out, but am confused on how this works.

BB
Re: Offer to Edit Maps
Board: OpenStreetMap
Reply to: #850829 by Bungalow Boxer
Jun 2, 2014 8:48am
Thread
The last time I edited a map (about a year ago) the only thing you could do was change the "type" of trail. Around here, there are so many mistakes in the type and location of roads and trails that it would take years to fix. That's part of the reason I gave up.
Re: Offer to Edit Maps
Board: OpenStreetMap
Reply to: #850829 by Bungalow Boxer
Jun 2, 2014 9:10am
Thread
I don't believe so. OSM has its hands full coming up with different lines for a couple of dozen different types of roads as well as hiking trails, horse trails, biking trails, you name it. You can NAME the trails, though! So I guess you could name one "Blue-blazed trail" or something like that.
Re: Offer to Edit Maps
Board: OpenStreetMap
Reply to: #850855 by RIclimber
Jun 2, 2014 9:25am
Thread
Apparently OSM began by loading something called TIGER data into its database. Whatever it was, apparently it was all wrong. There are arguments over whether it would have been better to start from scratch. Really, though, I think a user-edited system like this had to start with something. It's one thing to look at a map and say "that's wrong", it's quite another to look at a blank screen and figure out where to start.

One of the things that's looking up is apparently the use of the satellite photos when editing. Apparently, as I understand it, that wasn't always the case. People were asked to do GPS traces for anything they input, but running a GPS trace is another learning curve -- and could be really challenging before smartphones -- so evidently some people just drew in roads freehand about where they thought they should be. It's tempting to just delete those horribly-misaligned roads and start over, but remember that they often have the names of the roads, something you can't get from the satellite photo. So, whenever possible, I like to either pull that existing road to the correct location, or make a note of the street name before deleting it and drawing it in anew.

One other thing you'll run into a lot is roads that consist of zillions of nodes. OSM is all about the nodes; a road is just a string of nodes in a row. If you want to depict a road that's dead straight for a mile, all you need is two nodes, one on each end. To go around a curve, you need to put in enough nodes that it looks like a gentle curve rather than a series of sharp corners. But some of the existing stuff has waaaay more nodes than it needs, and sometimes they're not lined up right so the road looks all distorted. Sometimes nodes will even get pulled back over one another, resulting in what's called a "Zorro", where the road looks like it zigzags back and forth. The handy tip to know: You can reduce two sequential nodes to one by just clicking on one and dragging it to the other. In a matter of a few seconds, you can take a section of wretched-looking road with a dozen nodes and make it a straight section of road defined by only two nodes.
Re: Offer to Edit Maps
Board: OpenStreetMap
Reply to: #850863 by Kirbert
Jun 2, 2014 1:19pm
Thread
The problem here is whenever there was an error, someone just added the correct path of the road, without removing the wrong one! Most of this has been fixed over the past year.

I'd been focusing on hiking trails. Almost nothing there to correct, and I have always worked with a GPS track. I hike with a Garmin 60CSx so uploading the track isn't any extra work.

When done right it's great. Check out the huge state park near ZIP 02043.
Re: Offer to Edit Maps
Board: OpenStreetMap
Reply to: #850863 by Kirbert
Jun 2, 2014 8:56pm
Thread
Apparently OSM began by loading something called TIGER data into its database. Whatever it was, apparently it was all wrong. There are arguments over whether it would have been better to start from scratch.

Not ALL wrong, but often horribly misaligned. TIGER is the US Census Bureau's Topologically Integrated Geographic Encoding and Referencing database, containing features such as roads, railroads, rivers, as well as legal and statistical geographic areas. (From above link, with editing.)

One of the things that's looking up is apparently the use of the satellite photos when editing. [...] People were asked to do GPS traces for anything they input

Yes, I used to drive around to get good GPS traces to align the TIGER data to actual roads. The satellite photos are from Bing, which isn't quite as up to date as Google's data, but the Bing data is available. I also trace new roads from these images and trust that someone (maybe me) will fill in the names later.

But the satellite photos don't work well for trails that are under trees, so I still do those (that I hike) using GPS traces. I trace what I can then get the names from local trail maps. You can't get names from Google or other map sources, but I use the names from city web sites. I'm pretty sure that those are allowed.

However, I use Google as an "Enigma solution". During WWII, the Allies wouldn't use information gained from transmissions encoded with the Enigma machine directly; they would arrange for an aircraft to "accidentally" discover the troop or ship movement so that the Axis wouldn't know it came from an Enigma code break. (They sent out "misses" on purpose too so that the "hits" wouldn't be obvious.)

I find out from Google that there is something that needs to be mapped. I won't use this directly, but I will find some other source for the information. I'll first see if it is on the satellite maps used by the editor. If not, then I'll go and map it with GPS traces. For names, I'll go and find it directly or find some government web site that has the name. The US Census Bureau has some data newer than what was first uploaded, but I forget how to access it. (It's out there somewhere.) I think that this Enigma solution is also allowed.

The handy tip to know: You can reduce two sequential nodes to one by just clicking on one and dragging it to the other.

I've been editing for a long time and I didn't know this. I just select the node and hit the "DELETE" key.
Re: Offer to Edit Maps
Board: OpenStreetMap
Reply to: #850971 by Oberon_Kenobi
Jun 2, 2014 10:30pm
Thread
The satellite photos are from Bing, which isn't quite as up to date as Google's data...

The default satellite photo is from Bing, but there are about four others to choose from. When editing, the toolbar at the right has an icon for selecting the background image. Datawise, so far I haven't found one to be significantly better than another, but sometimes the terrain you're trying to make out shows up better in one pic than another. For example, sometimes one has a pic that was taken in early morning or something and there are shadows everywhere, while one of the other images shows it more clearly.
Re: Offer to Edit Maps
Board: OpenStreetMap
Reply to: #850974 by Kirbert
Jun 2, 2014 11:29pm
Thread
The default satellite photo is from Bing, but there are about four others to choose from. When editing, the toolbar at the right has an icon for selecting the background image.

I knew that it was somewhere and figured that Kirbert would be able to find it. Thanks!

I'm sure that you mean the menu at the upper-right, because that's where I found it. I found four types of aerial images, but the agricultural is significantly lower resolution, when available. Any of the US ones can be copied from since (except for some special cases) none of the US Government (public) data can be copyrighted. So that will be a source for names that I want to add to new streets.

The aerial images match the GPS traces that I've done so I trust them. The topographical maps appear to be off quite a bit in my area, but consistently offset. I won't be using the them for for tracing images but I can use them for place names. However, before the other aerial maps came along I used the agricultural maps (which are also off in this area) so I just offset my tracing (of mostly rivers) by the known error (which I got from my GPS traces). I could use this for trails that I can't see on the aerial images.

I'm very glad that you created this group Kirbert. I've been editing for quite a while, but I've learned a few things in the last few days. I could ask in the mailing list but that has such a large volume.