OpenStreetMap

AndrewBuck has commented on the following diary entries

Post When Comment
Elevation carving using OSM waterway data 6 months ago

Yeah, I plan to try to make the channel width and profile variable so that the original dem cut very roughly with the streams to force the dem to drain properly in the areas where we know how it should drain. Then run the drainage calculation and use the results to determine the signifigance of each stream. Finally, knowing this go back to the original dem and re-carve it, now using variable stream widths.

-AndrewBuck

Elevation carving using OSM waterway data 7 months ago

@JohnDoe23 Yes I am aware of the aretfacts, I think forests is a big part of why there are a lot along rivers because that is where the trees grow best due to the water. I do plan to take many things from OSM into account, not just landuse, but more sophisticated things as well, for example railroad tracks act much like a contour line since they cannot run at a steep grade, so you can gather elevation info from them just like you can with streams, etc.

@imagico Those are very interesting posts and I want to read through them all again in more detail. It would be very interesting to talk to you about this, can you connect to mumble (talk.hotosm.org) sometime or contact me on skype (my username there is the same as my name on this site except with a '40' at the end of the name)?

-AndrewBuck

Elevation carving using OSM waterway data 7 months ago

@Hedaja @mcld Yes, in theory you can get elevation from GPS traces but there are a lot of problems. What I am trying to do is to take a different approach. Rather than trying to determine the absolute elevation of each pixel accurately, I am more interested in using the "hints" that the OSM data gives us about the relative elevation of a pixel to other nearby pixels. The ASTER and SRTM data are already pretty good once you get up to more broad scale elevation (beyond about 100 meteres or so), this is just to fill in the details and make them more suitable for really small scale mapping applications like high zoom level contour lines or for things like flood simulation, or terrain models for games, etc.

Regarding this "relative" elevation hints, this work grew out of an idea I have been working on for a long time. I started trying to document some of it a while back at the following wiki page. Feel free to add any other tags that might be relevant. Don't worry about filling in the other columns if you don't understand them, but anything that might tell you about the elevation of the ground either below or nearby the mapped object.

http://wiki.openstreetmap.org/wiki/OpenTerrainModel

@Nick I added the elevation difference from the carving, that was a great idea, it will really help me understand where my algorithm works and doesn't work going forward.

-AndrewBuck

Population estimates in west africa (preliminary results). 7 months ago

Yes it would be possible. It is important if you do this though to make sure all the landuse=residential areas are drawn around the villages in a consistent manner. Have a look at how Pierre and I do the borders around the villages in the southwest region there and that should give you a good idea how to do the borders to keep it consistent. Since the bulk of our analysis is based on the area of the village, making that polygon fit nicely is very important.

For the test villages I don't tag the number on the area I just map the actual buildings and huts in OSM and then use QGIS to count how many buildings are in each residential area. I can help you get started with building tools if you are interested in mapping the test villages to seed the density calculations.

-AndrewBuck

Not-very-useful GPS traces over 1 year ago

Also known as "null island". A lot of stuff ends up there. Not just GPS traces but nodes, etc. You also see a lot on the equator that obiously don't belong there where just one coord got 0.0 and I assume the same happens along the meridian. I have also heard the poles collect nodes too but haven't seen it myself.

-AndrewBuck

Keepright trends in my area over 1 year ago

Having a bot remove single nodes is not a good idea. The redaction bot left those nodes behind on purpose, to help future mappers re-create the missing data. There were pros and cons but the debate was had and ultimately decided to do it this way. It is good that you are interested in seeing them cleaned up, but unfortunately a careful manual approach is needed, not just a quick bot run.

Regarding the node in a building thing, I agree and I think that is the general consensus as well. If you try out josm, you should check out the 'replace geometry' function in utilsplugin2 is very good for "upgrading" nodes into areas.

-AndrewBuck

Hallo over 1 year ago

Welcome to OSM, glad you converted over from mapmaker. :) As I am sure you already know from your editing here, we are much more open to having things like your pathways example and fun stuff like that. The other big issue you forgot to mention in your list of mapmaker problems is that all the data you give to them just goes into a "black box" that google controls and can release or not at their own whims, but with OSM you or anyone else can play with the data and do cool stuff with it.

Hope you keep using OSM and have fun with it. Let us know if there are any questions you have. I assume you probably are pretty familiar with the project with as long as you have been mapping, but there is always more to learn. :)

-AndrewBuck

Do OSMTrack on iPhone refers only GPS data, or also refers iOS map? over 1 year ago

You need to check the option in the map app you are using to make the GPS traces. Some apps will try to snap the GPS fix to the nearest road. You need to make sure you are not doing this as if you do, the snapped tracks will inadvertantly copy the apple maps road data into our GPS database which could introduce copyright issues. If the app you are using uses OSM as the map data then the snapping is less of a problem copyrightwise, but still makesthe gps data less useful for trying to improve the map by aligning imagery, etc. IT could just be errors though too, hard to say, although it does look fairly precise just to be an error that just happens to follow the road.

-AndrewBuck

Getting started... over 1 year ago

Yeah, there were some problems with the database this morning so that is probably why your downloads failed.

For collecting survey information you should check out the 'field papers' website. You print out a map of an area on on paper, then you can walk around and take notes on those pages, then you take a picture of your notes and upload them to the website. Finally the website will make your notes available as an imagery layer right in the editor, so you can copy them into the database. http://fieldpapers.org/

Another really good way to collect a lot of information really quickly is a technique called audio mapping.

Keep up the good work, and welcome to the project. You can map pretty much anything that interests you so just because the map has a lot on it already, don't let that discourage you; there is always more detail to add. :) Remember to have fun, and feel free to ask if you have any questions.

-AndrewBuck

Extending to JOSM over 1 year ago

Although there may be no technical reason for ordering them, it does make them a bit easier to work with. I wouldn't put a lot of effort into ordering them manually though, there is the 'sort' button in the relation order to do it automatically, but I don't know if I would edit the relations just to change the order. Definitely worth doing when you do make some other change to the route, however.

-AndrewBuck

Today's updates over 1 year ago

Be aware that 'unclassified' does not mean, no one has classified the road yet, this is what highway=road is for. Unlcassified is actually an actual classification, being the lowest level of road in a country. A lot of people get confused about this since the naming scheme is somewhat ambiguous. Check the wiki page for highway=unclassified for more details on this.

-AndrewBuck

Mapping Rock County over 1 year ago

By the way, you should check out JOSM and the 'building tools' plugin for tracing buildings. It is much less work to trace them, and produces a better result since the corners are nice 90 degree angles. Definitely worth taking the time to learn if you plan to do much building mapping. There are some good videos on the wiki about how to use it effectively.

-AndrewBuck

Mapping Rock County over 1 year ago

Yes, looks very good. I have been doing similar landuse coverage west of Fargo as a test experiment in how the result looks and was happy with the results. Good to see someone on the other side of the line doing similar work.

Keep up the good work. Bit by bit the landuse in the midwest is being done, I think it will be really interesting when the coverage gets more complete.

-AndrewBuck

Help us map Mali for humanitarian relief over 1 year ago

Don't worry about missing the dams. The tool is still a work in progress and we are still refining exactly what to map and what zoom level to use, etc.

The dams themselves are only of secondary importance anyway. We are mapping them because water (of any kind) is important in a desert area, but our primary goal right now is to help aid organizations, and they are concerned where the towns are. The townspeople they help will know where the water is, so the main problem is to find the people. :)

Anyway, thanks for the help marking images, and thank you to anyone who shared the links via twitter/facebook. The 'referrer url' records on the webserver show a couple dozen people found the site through these links, so please keep sharing them. We will probably be putting up some more imagery in the future so check back and tell you friends.

-AndrewBuck

Guided Tagging by an interpreter of XML-formated rules almost 2 years ago

I am actually currently working on something like this right now. It is called OSM Logic, and it is an OWL ontology which is designed to give semantic meaning to the various concepts in the OSM realm, as well as to create a machine readable database of tags and how they relate to one another.

For example, the tag section of the ontology lists individual tags and then uses relations to show when one tag implies another tag, or that one tag is equivalent to another tag, and when there are equivalent tags which one is preferred and which are deprecated, etc. I had considered the possibility of adding things like names in various languages, and short descriptions of the tags to this as well (the OWL language actually provides some support for this itself).

The ontology is still being developed and is still in what I would call a "pre alpha" type of phase, so I have not posted it online yet (but I am getting close to releasing it now to alpha stage). When I do release it I will write a diary entry describing it in detail and how I envision it being used.

The ontology itself is much bigger than just what you described here, but the tagging subsection is almost an exact match for what you described, although you do list a few things I had not specifically planned but maybe they could be added as well.

-AndrewBuck

Is it funny or is it for real almost 2 years ago

There is a brewery in New Ulm, Minnesota that has a "beer garden" surrounding the brewery, so I would guess this is the kind of thing that the mapper was meaning to indicate. The brewery facility itself though is probably a landuse=industrial.

-Buck

Dixie County almost complete about 2 years ago

Nice work. I live in North Dakota and we have a big problem with the tiger residential->track issue here as well. I have done a bit of cleanup in the immediate area but there is still a lot more to be done. Little bit by little bit though it is all getting reworked. Hopefully in the next couple years we will have complete road classification done.

-AndrewBuck

SF Fisherman's Wharf Hotels about 2 years ago

Welcome to the project. Looks like you figured out how the editing works. Hope you enjoy working on adding more things and have fun with it. We need people's local knowledge from all over the world to improve the map.

Remember, we cannot use any information taken from other maps because we want to be able to share our data with anyone who wants it.

Let us know if you have any questions about adding anything else.

-AndrewBuck

Wierd stuff with the rendering about 2 years ago

Oh, by the way, just to clear up some info from above, adding /dirty to the tile URL does force a re-render of the tile. But the coastlines shapefiles are built using a separate process as mentioned, and it is these files which are out of date, so re-rendering the tile will update all the roads, etc, in the tile, but the coastline will still look the same until the shapefiles are rebuilt by the admins.

-AndrewBuck

Wierd stuff with the rendering about 2 years ago

@Jopparn

The coastline rebuilding does not happen automatically every two weeks, but rather it happens manually whenever the admins get around to running it. Recently there have been a lot of changes to the project happening and so coastline rendering has fallen by the wayside.

Just keep making your changes and they will eventually get shown on the map. I do a lot of coastline work myself and it gets frustrating sometimes as it takes a while to show up but you learn to live with it. (There was about a 4 month gap before the last coastline rebuild) As long as it looks right in the editor then you have done what needs to be done and the update process will happen eventually.

-AndrewBuck