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OSM Rank Table update, and TIGER burndown

Posted by bdiscoe on 17 October 2020 in English.

I update the OSM Rank Table for the first time in over two years: http://jiografik.com/osmrank/table_planet.html

My own blended rank has slipped from #9 to #10, with import accounts “osmviborg”, “Reitstoen_import” and “JandaM” leaping up into the top 10.

I also updated the TIGER node/way burndown chart, and it shows the cleanup continues in an incredibly stable rate, exactly matching the trend line from previous years: TIGER burndown At this rate, we still have over 29 years before every imported TIGER node is touched, and over 9 years before every way is touched - hopefully, aligned and cleaned up.

TIGER node/way burndown

Posted by bdiscoe on 19 June 2018 in English.

The TIGER import in the USA is one of the largest and messiest imports in OSM, but of course it is getting cleaned up over time. It can be hard to estimate progress, but one rough metric is the number of nodes and ways that haven’t been changed since import. This number goes down over time. For the past 3 years, I’ve been tracking these numbers in a spreadsheet.

  • For nodes, it is the last-modified-by for accounts ‘woodpeck_fixbot’ and ‘TIGERcnl’
  • For ways, it is the last-modified-by for accounts ‘bot-mode’ and ‘DaveHansenTiger’

Over the last 3 years (since June 2015):

  • Nodes have decreased from 139.6 to 127.6 million (average 11k/day)
  • Ways have decreased from 8.00 to 6.08 million (average 1688/day)

burndown

What’s remarkable to me, as you can see from the trendlines, is how steady the rates are. At this rate, all of TIGER won’t be cleaned up (or at least touched) for another 31.7 years (for nodes) or 9.9 years (for ways).

OSM rank table changes 2018-03-15

Posted by bdiscoe on 16 March 2018 in English.

I won’t always refresh the table with the weekly planet file update, but I did today with a delta to 2 weeks ago. (The previous table is at table_planet_180301

Some observations, in nodes:

  • Despite another round of my vigorous cleanup in Ontario, the ‘CanvecImports’ account only dropped by 600k from 39.5 to 38.9 Mnodes. Still so much Canvec to clean up!
  • Import accounts that were active include: ‘StefanB_import’ +14, ‘Svein Olav’ +119, ‘osmviborg’ +132, and ‘Rúdisicyon’ (+434!) which is doing a giant import of buildings in Portugal.
  • Other accounts that moved up in rank, which are probably due to good active mapping and not imports, included ‘indigomc’ +14, ‘santamariense’ +11, ‘Kohki Hiraga’ +15, ‘Hernan’ +18, ‘yunita sari’ +28, ‘Ben97’ +40, ‘hpduwe’ +13, ‘yuantouniaoren’ +65, ‘jpgon’ +14, ‘ajithkarunaratne’ +25, ‘dubf’ +48, ‘Hendrikklaas’ +23, ‘baradam’ +12, ‘chachafish’ +19, ‘Sander H’ +17, ‘DaCor’ +10.
  • HOT/MissingMaps active users ‘asmi84’ +59, ‘ASHIQ MAHAMUD’ +31, ‘Raven Nahid’ +77, ‘anisa berliana’ +13, ‘Nodia’ +567, ‘Abou kachongo jr’ +52, ‘dianawa_22’ +11

In ways, I notice some of the same activity, and also:

  • ‘kiaraSh-Q’ who maps mostly Iran, somehow moved down in nodes (-59) but up on ways (+41).
  • Mysterious drops ‘Canyonsrcool’ -52 and ‘alester’ -36.
  • ‘Matthew Darwin’ (+22/+23) seems to be impressively fixing/aligning every road and address of Ottawa, Canada.
  • Some Japan-import-account drops are probably due to the cleanup work that myself and other Japanese users have been doing there, hence ‘chnkshm’ -7/-17, ‘KSJ2_adm_bnd_imprt’ -16/-283, ‘nyampire’ -14/-21, ‘watao’ -5/-105.
  • User ‘PierZen’ (+4/+539) seems to be doing a bunch of cleanup in Quebec, including boundaries and removing superfluous tags.
  • Other active global users who moved up in ways include ‘vichada’, ‘de vries’, ‘Seandebasti’, ‘JFK73’, ‘edvac’, ‘danbjoseph’, ‘Alan Bragg’ and ‘gscholz’ (+3/+57).

Issues with Japan imports

Posted by bdiscoe on 3 March 2018 in English.

I’ve run my find_small_displacements program on Japan, and found some problematic imports with a large number of densely overnoded features, here are some:

  1. Bad import of natural=wood around Fukuoka. These were tightly spaced, yet also wildly inaccurate, off by as much as 80 meters and covering lots of non-wood areas, even covering motorways. I’ve reduced most of them, and aligned a few areas, but there’s lots more to align. The original upload was in 2010 with changesets like this one.

  2. Bad waterways, especially in Hokkaido and Kyushu, but also across the country; these are not just overnoded but also overtagged, consider this little stream near Taketa, Ōita:

  • KSJ2:COP_label=1級指定区間
  • KSJ2:DFD=流下方向不明
  • KSJ2:LOC=c03671
  • KSJ2:RIC=8909180118
  • KSJ2:RIN=軸丸川
  • KSJ2:WSC=890918
  • KSJ2:curve_id=c03671
  • KSJ2:filename=W05-07_44.xml
  • KSJ2:river_id=gb02_03671
  • layer=-1
  • name:ja=軸丸川
  • name=軸丸川
  • note:ja=国土数値情報(河川データ)平成18年国土交通省
  • note=National-Land Numerical Information (River) 2006, MLIT Japan
  • source=KSJ2
  • source_ref=http://nlftp.mlit.go.jp/ksj/jpgis/datalist/KsjTmplt-W05.html
  • waterway=river

See full entry

The return of the OSM rank table

Posted by bdiscoe on 3 March 2018 in English.

To follow up from my previous post, I did some further work on generating and putting online a table of OSM node/way ranks table

The data that’s there right now is from today (2018-03-01) and the deltas are vs. 2 weeks ago (2018-02-12).

Standard disclaimer: Last-modified-rank is only vaguely related to contribution, there is no way at all to measure actual quality or value of contribution across users, because it’s subjective, and users are very different from each other. However, this table can be very useful for an individual mapper to see how their amount of contribution changes over time, and to identify, for example, accounts that are moving up rapidly which usually indicates they are doing an import. Similarly, if your rank moves down, it can mean that someone (correctly or not) has modified or deleted your mapping work.

For those curious about the technical mess that’s currently involved, here is what I did:

See full entry

How to track and encourage contribution?

Posted by bdiscoe on 15 February 2018 in English.

As I’ve been mapping heavily since 2013, I’ve tried various ways to track my progress. It’s really great to feel that your mapping is making a visual and statistical difference! However, as of today, there is no good metric, and it’s very frustrating. Understandably, there is no way at all to measure actual quality or value of contribution across users, because it’s subjective, and users are very different from each other. However, for me, I know that I map at a consistent quality and node density, so I should at least be able to measure my progress with respect to myself! Here are things I’ve tried:

See full entry

Emmor (account Palolo) asked some questions in an OSM message, I’ve put my response here as it may be of general interest.

On 2016-09-26 22:32:47 UTC Palolo wrote: > Ben, Thanks for your contributions to OSM, especially for the rivers you have cleaned up > on the west coast. I also just came across your spreadsheet tracking users and find it fascinating. > > I was wondering if you could convert your notes into 3 categories of mappers: > 1) Imports, 2) Mappers, 3) Combination mapper/importer ?

That’s a good question, I’ve considered trying it, but it can be difficult to tell them apart, or it requires individual detective work that I just haven’t gotten around to. Generally, for the import or part-import accounts, I’ve put the title of that import in the “Grouping” column.

If they have added millions of nodes, and there is nothing about importing in the “Where, What” or “Grouping”, it means I haven’t been able to figure out if they are an import account or not. For example the Japanese accounts, “Tom_G3X” and “ikiya” and “yamasan”. They are probably imports(?)

I’ve also put the account name in bold (like katpatuka and Heinz_V) if they have contributed millions of features without any obvious importing. Anyone who belongs in this category that I’ve missed, please let me know!

Also have you thought about gender classification?

I’ve thought about it, but it is also very hard to tell. Very few account names/images are clearly gendered, and nearly all those that are, by name or image, appear male.

It appears to me that there are very few female top contributors. I wonder why this is since it is open for anyone to edit.

Probably for the same reasons that cartography and technology in general is so male, cultural bias encourages it for men and encourages other things for women.

See full entry

When I read Michal Migurski’s recent post robots, crisis, and craft mappers, I was really baffled and concerned. I am a fan of Migurski; he’s a good person and a smart guy. But the content of this particular blog post was really off. I had hoped it would pass with little notice, but I can tell from the #craftmapper T-shirts at SOTM that people actually paid attention, so sadly I feel compelled now to rebut, and hopefully offer some useful perspective as well.

To get something out of the way first, I am absolutely a “armchair” or “craft” mapper, and an addicted mapper, averaging ~5 hours a day mapping for the past 3.5 years; by my own estimation, there are only two human OSM accounts (katpatuka and Heinz_V) with more node/way contribution. (Also, shoutouts to AndrewBuck, Stalker61 and ulilu!) I care passionately about the map, I’ve been in geo since the 90s, and I’ve been inside Google to see how mapping actually happens at scale.

My OSM Heat Map

To start with, he writes:

See full entry

Relations for Big Rivers

Posted by bdiscoe on 7 August 2016 in English.

My first big river, in 2014, was the Klamath. At first, I tried looking for it using the OSM search box (Nominatim). All I found was a mess of missing river parts, and when I looked closer, I found poorly imported NHD, very old and wrong riverbanks, incorrect tagging, etc. I spend a few days to fix it up and produce the Klamath River waterway relation:

Klamath

Since then, I’ve done similar work for other waterways. Sometimes the relation exists but is incomplete, other times I create it; either way, it can take days of work to finish. Here are some in the USA:

Recent work in Illinois:

Outside the USA:

#MapLesotho National Parks

Posted by bdiscoe on 8 May 2016 in English.

I’ve been contributing heavily to the #MapLesotho project for a while, and we’re making great progress on all the basic geometry of the country, like roads, paths, buildings, waterways. A good OSM map of a place has more than that, it has things like POI and amenities, which are hard for an armchair mapper like me to help with. One thing I can do, however, is protected areas. Lesotho is a small country with only a few protected areas, two small “national parks” and some even smaller places. There was no vector source for any of them (neither open nor closed), but by doing a bunch of online research and detective work, and reading wikipedia, I was able to add the two largest:

See full entry

"Urban India" mappers?

Posted by bdiscoe on 8 May 2016 in English.

While watching the OSM ranks and daily activity of the top thousand accounts, I’ve noticed a curious pattern: a number of accounts which all edit in the same places, the very largest cities in India (New Delhi, Mumbai, Bengaluru, Hyderabad, Kolkata, Chennai…) Their edits are so similar that the accounts must be connected, as if they are all working for a company, school, or other organization. However, their account pages are blank (unlike, for example, Mapbox accounts, which plainly state their affiliation).

Here are the top “Urban India” accounts: saikumar, premkumar, jasvinderkaur, anthony1, Apreethi, sdivya, shekarn, himalay, Navaneetha, praveeng, harisha, himabindhu. I know of at least 20, but I think there are many more. Many (most?) of the accounts have been active since sometime in 2015.

I am very happy that someone is coordinating work on India’s cities, but I would be very curious to know who it is! After all, companies like Google have whole buildings full of workers (in India) to update their proprietary maps. Is someone doing the same for OSM? I’d like to thank them.

Here is a picture of premkumar’s edits; all the accounts look very similar to this:

See full entry

About Huts

Posted by bdiscoe on 20 December 2015 in English.

Particularly in Africa, there are huge number of small round buildings. I believe the best way to model them is with a single node, tagged building=hut; optionally with a radius or width. However, the dominant OSM practice is to use a whole way with lots of nodes. So, I must go along with the community. Unfortunately, I encounter a lot of this while working, for example on #MapLesotho

Huts

That’s 7 huts, 130 nodes, all the wrong size, some overlapping - likely the result of very bad copy and paste. (There are actually 8 huts there; they missed one.)

My fingers have developed the rhythm for cleaning this sort of thing up in JOSM. First set the simplify-way.max-error to something appropriate (0.3), then for each hut:

  1. Click to select buliding.
  2. ‘G’ to unglue it from the surrounding buildings, if needed.
  3. Drag to center it correctly.
  4. Ctrl-Alt-drag to scale it down to the correct size.
  5. Shift-Y to reduce nodes.
  6. ‘O’ to re-round the circle.

Within a few seconds I have this:

See full entry