OpenStreetMap

bdiscoe has commented on the following diary entries

Post When Comment
"Urban India" mappers? 20 days ago

Wow! Thanks Muralidhar, that explains it. I am delighted to learn about Zippr and its mapping efforts, thank you and your very impressive team!

That said, I would recommend that your dedicated cartographers (like saikumar) put at least a brief sentence on their account page linking to Zipper, just like Mapbox mappers (like ramyaragupathy) link to Mapbox.

About Huts 5 months ago

@MKnight Indeed Shift-Y, I've corrected it above. Apparently my fingers know it perfectly, but my higher brain not always :)

@SomeoneElse The only "benefit" to going along with community practice is that people are happier, I don't have to respond to dozens of messages on HOT tasking manager telling me my 1-node huts are "wrong" and "please read the instructions". Most of OSM is based on rough consensus and there's a limit to how much energy I want to put into arguing about tagging or other practices; it's "pick your battles" and otherwise just go along.

About Huts 5 months ago

It's almost always "too many" poorly placed nodes, but just now I found a rare example of "too few":

too few

I'm guessing this newbie apparently considered nodes and ways so precious that they attempt to cover multiple huts with a single minimalist blob :) and yet they still manage to create bad overlaps and self-intersections. I want to applaud their urge to model efficiently... but I'm still stuck slogging thru cleaning this up :)

Japan in OSM - The whole picture 6 months ago

The link is broken ("@Rub21 made a script") to https://github.com/mapbox/data/issues/1489 Where is this script?

Cleaning up NHD in North Carolina 6 months ago

@gormo Thanks for pitching in on SC. Your cautious approach, to avoid deleting waterways is generally good OSM practice. That said, sometimes its very obvious that a pond/stream has been destroyed and replaced with a shopping center or golf course. I have no issue with removing/updating the clearly non-existent waterways; you could do that (or place notes).

@SK53 I feel very comfortable with the waterway tags. I understand the ditch/canal distinction the same as stream/river, only with artificial waterways. In either case, the crossover is around 3 meters of visible water / potential water area. Both ditch/canal and stream/river have some intermediate-sized ones that could go either way. I understand "drain" as a ditch which is so skinny that it has little or no visible/potentially visible water. Practically every artificial waterway in NHD is a ditch or drain; there are really very few canals, even ones with "Canal" in their name like the Denver "High Line Canal" which is definitely a ditch by OSM's definition.

In other parts of the world (like Sudan and India) they have vast expanses of canal-sized irrigation waterways; I haven't come across much of that in the USA at all.

I too spent some time on the Colorado Basin, especially in the Grand Valley, starting around the town of Mack and working my way south-east; I got only part way to Grand Junction, fixing the NHD (mostly changing "canal" to ditch/drain and applying intermittent=yes to nearly every stream). That task is unfinished :|

Cleaning up NHD in North Carolina 6 months ago

@imagico you wrote about "projection distortion" and "scale independent". AFAICT, JOSM already does this correctly. In fact while I was writing my Osmium-based simplification test code, I spent hours looking at the (many!) ways to approximate displacements, but finally just adapted the code directly from JOSM itself (SimplifyWayAction.java) translating from Java to C++. (See all the geodetic stuff in there about EARTH_RAD and "Aviaton Formulary v1.3")

As for river/stream classification, among all of NHD's many issues, I haven't seen much trouble with that (the classification usually roughly matches the imagery, at least), but I have seen some NHD in western Colorado where all the ditches/drains came in as "canal", that was clearly wrong.

@SK53 I apologize for "decimation" as jargon, not so much from GIS, more from computer graphics (my background). At least I managed to avoid calling them LODs :)

A Mapper in the Spotlight: Dave Swarthout (USA/Thailand) 6 months ago

Hi AlaskaDave, you mentioned the Susitna River and that got me interested in it... first I looked at the "Little" Susitna, I saw you had done some work on that... I made a relation for the whole course: http://www.openstreetmap.org/relation/5704982

For the "Big" Susitna, I found the relation you had already begun (http://www.openstreetmap.org/relation/3461951) so I filled it in to connect it from source to sea, smoothed some of the PGS river islands, added riverbank along the upper reaches, added tributary streams, etc.

Starting with OSM Mapping: Mapping my hometown, Jorhat 6 months ago

I saw the Mapbox blog post and was inspired to spend some time armchair mapping Jorhat this evening, added hundreds of more details, mostly in the area around the town. I can only add geometry tho, so someone local needs to fill in the names!

Missing Roads - The Missing Manual 8 months ago

It's working great for me; i added roads it found in a few places. At least one place was quite dramatic, the entire large town of Cortazar, Mexico, entirely missing from OSM; i added just a bit of it.

My only feedback on the plugin is the red circles, they jump around quite oddly, sometimes they just vanish for no clear reason. When i do get one to stay steady, i can zoom in and find the tiles. Perhaps this is just a result of the clustering algorithm being used. In that case, perhaps the clustering could be a little finer-grained (more points, less clustering) so it isn't so jumpy.

Did somebody delete Hyderabad, India? 12 months ago

Thanks for the great work everyone, I see Hyderabad is back on the map. I also refreshed the main site's cache so it appears on zoom levels 7-12. It's even showing up in Nominatim - that was fast!

I am wondering about setting up some kind of process to get notified when someone deletes or commits a change anywhere to a place=town or place=city. We could catch this sort of thing more quickly and not have to wait for someone to stumble across it.

Top OSM Rank: Who are these crazy, amazing people? almost 1 year ago

Thanks @EdLoach, I've noted that you are not a bot :) That's great details on your wiki user page!

Top OSM Rank: Who are these crazy, amazing people? about 1 year ago

@PurpleMustang I would say that CanvecImports has made more than "a dent" with noderank #3 :) and your main account is also impressive.

@joost schouppe Thanks for the props to lodde1949, I've added that note.

@DaCor I've added you now :) I would have found you sooner if you showed up as recently active on http://www.openstreetmap.org/stats/data_stats.html (not sure why not).

Top OSM Rank: Who are these crazy, amazing people? about 1 year ago

@Stalfur, there should be an award for "most disparate places", I cannot imagine two countries less alike than Iceland and Botswana! There is user "ulil" who has done a lot of work in exactly two countries: Paraguay and Georgia, and "mindedie" Lithuania and Hokkaido.

Top OSM Rank: Who are these crazy, amazing people? about 1 year ago

@ViriatoLusitano, that's one of the first things I found, Katpatuka is truly a superhuman :) I think he almost-singlehanded put the countries of Turkey and China on the map :)

@naoliv, BlendPoints was just an experiment to combine node rank and way rank (weighted equally) into a single value, on a scale of 1-1000. I think it actually tells less than looking at the node and way ranks separately.

@Skippern, you can be proud of the extensive work you've done along the coast above Rio de Janeiro! You can sort by the "Where, What" column to see all the other main contributors to Brazil.

(Actually) fixing the Peoria GIS import about 1 year ago

@Nakaner, it's not that bad. Really all that was wrong was the building tags, and excessive detail on the woods. The building geometry is actually very high quality and perfectly aligned to Bing, and since most of the buildings that existed in 1997 still exist today, it's perhaps 99% accurate.

@JBacc1, I agree. Perhaps import procedures have gotten better since 2010? In particular, people are usually better about decimating data, I don't see extremely excessive nodes very often... except sometimes... I should write another entry about that big subject.

New mapping addict over 1 year ago

Hi Jimmy, welcome to OSM. I took a look at Launceston; it's a pretty large area. I started to work in the southern part, Prospect Vale and the area S of Meander Valley Road. Is there any particular part of the Launceston area that could use some attention from those of us who are advanced armchair mappers?

Come work on #MissingMaps with me! over 1 year ago

Hi SDavies, you're probably right. E.g. I contributed to http://tasks.hotosm.org/project/797 and rapidly found myself the only person doing that one, too.

BTW, I took a stab at Project 727 just now and filled in the last few tiles to get to 100%. Yay!

Come work on #MissingMaps with me! over 1 year ago

Hi Warin, yes it seems that in many developing countries, even with a lot of tree cover, where the people live is very bare (possibly because of grazing animals, or firewood collection, or both). So, the roads (and paths, buildings etc.) are all very visible. You can see on that link (#793) that the target is a large town / small city, so it is not just roads.

Map Somalia over 1 year ago

You will find that almost all of Somalia's current OSM data (especially northern part of the country) was uploaded in 2008 with the change comment:

"Mart Roumen; FAO-SWALIM; Madmappers-SOM-2008-01"

The good news is that because of that 2008 upload, Somalia has at least some data, it is not blank. The bad news is that the accuracy is very low. There are many problems, especially with classification, for example, many almost-nonexistent trails (temporary camel tracks?) are marked as highway=primary.

I spent a lot of time to clean up the "Mart Roumen" data in many Somali cities and villages (Borama, Hargeisa, Burao, Laasacanood, Berbera, Galkacyo, others). But of course, it is a very big country and I cannot possibly do it myself. Good luck!

JOSM scripting plugin: be a power user! about 2 years ago

For those interested, a later version of the script which handles "blvd" etc. and is better written is available at https://drive.google.com/file/d/0B-Csp1lvUfO8RVpZbU9zTXR5Y3M/edit?usp=sharing