Diary Entries in English

Recent diary entries

Manifesto for the OSMF Board, 2015

Posted by IknowJoseph on 19 November 2015 in English (English)

I love OpenStreetMap. I joined in early 2008 because I wanted to map the village I grew up in. Since then I've mapped around the world, both from knowledge of places I've visited and from the wonders of aerial imagery. OpenStreetMap was small when I started to contribute - it was a hobby for people who liked computers and geography - but it has since grown into a leading example of Open Data and online collaboration. I am standing for the OSMF Board because I would like to see OpenStreetMap grow further; I believe that the database behind our homepage can soon become the basis of the default map that people view online.

If the world is going to move to defaulting to OpenStreetMap for its map data the OSMF is going to have to facilitate the process. I see two elements to this: Increasing the quantity and quality of data entering the database, and encouraging data consumers to take these contributions and use them as the basis for their mapping.

The OSMF should be encouraging worldwide participation in mapping via the strengthening of local chapters and the empowerment of traditionally under-represented or marginalised groups. The OSMF should be working to increase the power of international stakeholders who contribute to OpenStreetMap for their own niche interests, as long as these interests improve the map for everyone.

At the same time the OSMF should be promoting the data we have and making it more readily available to organisations, for profit or otherwise, who wish to build products and services from our data. Our data - the thing we all work to improve - is an incredible resource and the OSMF needs to be doing everything it can to foster and promote it.

The OSMF needs to work effectively with the resources available to it. The current working of the OSMF, I argue, could be improved to not only produce better results, but also do so with more accountability and transparency. For example, if required, the OSMF should employ staff or contractors for work that is needed to be undertaken. This is just one pragmatic decision that could be made to improve the map for everyone. The OSMF needs to move away from the hobby attitude that kick-started OpenStreetMap in the first place; at this stage of the organisation’s development we don’t need individual egos and personal histories, we need effective leadership and representation.

I am putting myself forward for this position in the hope that you will agree with my sentiments and choose me as one of the next Board members. I have previously served as a member of the Humanitarian OpenStreetMap Team Board and learnt a great deal from what was a challenging position. This experience ensures that I know that serving on the OSMF Board would also be a challenge and, at numerous points, presumably not an enjoyable role to undertake. I am sure, however, that by working on the Board I could, with my fellow members, develop the OSMF for all.

I love OpenStreetMap as it is an incredible patchwork of niche interests and groups that collaborate towards an ecosystem that benefits everybody. This amazing spirit of cooperation not only needs to be encouraged further within the wider OSM community, but embraced tighter within the OSMF itself. If we work with this goal in mind we can create the best technical output, the best working environment, and the best community for everyone.

Location: Grandpont, Oxford, Oxfordshire, South East, England, United Kingdom

OSM Dark Theme

Posted by 51114u9 on 19 November 2015 in English (English)

osm-after with a dark theme

I created a dark theme for my desktop environment (xfce) with a dark theme. My simple GreaseMonkey/TamperMonkey/VioletMonkey script is applied into the header, sidebars, panels and leaflet elements and partially into iD editor.

How to install

Read the install section at

Feedback and Contribute


GIS Day in Lomé and Haiti in the middle of two OSM and GIS capacity building missions

Posted by Nicolas Chavent on 19 November 2015 in English (English)

"GIS Day" 08 PM (UTC), it's mid day in Port Au Prince (Haiti) and night time in Lomé (Togo) after long and happy working hours around OSM, GIS and opendata.

In Togo at Université de Lomé UL (Lomé University UL): - 50 people working all day long on QGIS with OpenStreetMap data created through the first 4 days of the maptrek mivamapper (Come map Togo local language) in Anfamé (Lomé) but also with data from the OCHA Core Operational Datasets (COD) and Fundamental Operational Dataset (FOD) accessed via the Humanitarian Responses and the HDX platforms. - 20 people working half a day exploring, visualizing and retrieving geodata of all sorts (openstreetmap, opendata, gray-licensed data) with the IFL (Infrastructure de Données Spatiales Francophone Libre/ "Free Francophone SDI"-FFS) hosted in France at AgroCampus Ouest and maintained with the support of the GeOrchestra community. - The same 20 spent their afternoon reinforcing their grasp on the webmapping tool uMap with the same kind of data - Asides of this, the same people kept mapping Anfamé and Biu cities as the first targets set for the mivamapper maptrek experience started last Saturday 14-November (our 8 days-long mapathon) - Now that night fell over Lomé, the preparatory work for our second State Of The Map Africa, the SOTMTG 2015, is intensifying.

In Haiti at the Port Au Prince base of Haiti Communitere, - a couple of Haitian experienced mappers are being taught OSM on a train the trainer program - The same with the ProjetEOF collective are also organizing for both remote attendance of the SOTMTG 2015 and the last day of mivamapper - They are also laying the ground for a mapathon that will take place this 21-Nov at HC's base and will focus on Areas Of Interest for local communities in Haiti - Like the days before, they'll finish their days joining in Western African mappers in the mivamapper maptrek.

A rich GIS day like most of our days in Haiti (1, 2) and in Togo (3, 4, 5) over the past 2 weeks and likely of the coming 10 days.

Excellent day to all Nicolas

easy undelete of several ways

Posted by malenki on 18 November 2015 in English (English)

Second tought on my older posting about partially deleting changesets. Again, it is also a note-to-self.
Only helpful, if you have a bash with the usual tools at hand. For Windows there is Cygwin providing these.
You need a JOSM with the undelete plugin installed.

deleted objects of a changeset Example-Changeset with deleted objects and some of them selected for copying

If you stumble over a huge changeset and only want to undelete the deleted ways in that changeset without a time consuming revert of the whole changeset proceed this way:

  • copy the ways you want to undelete (mark them, press ctrl-c)
  • save them in a file foo
  • execute run on the command line

     less /path/to/file_foo | awk -F "," '{print "w"$1","}'|tr -d "\n[[:blank:]]"|sed s/[a-z],w/w/g|sed s/[a-z],r/r/g|sed s/[a-z],n/n/g
  • this results in a line looking this way:

  • copy this line, switch to JOSM, press shift-alt-u, paste the copied line, press enter

  • all the ways will be undeleted

  • If you want to undelete nodes or relations, do as before and only replace in print "w" the w with n for nodes or r for relations

Having a lot of time, here the

Explanation of the command

  less /path/to/file_foo | 

sends the content of file_foo to a pipe from where the next tool can parse the content.

  awk -F "," '{print "w"$1","}' |

Tell awk it gets a string separated by commata and to print the first column which in our case is the ID of the way. Additionally it has to print a "w" in front of it so the undelete plugin later knows it has to undelete a way. The comma is added to later have a nice line without spaces. The output is again piped for the next tool.

  tr -d "\n[[:blank:]]"|

Tell the tool truncate to delete all newlines to make the list of ways a single line. Additionally, have it delete all blank spaces which may occur from copying and cause a broken list. Again pipe the result.

  sed s/[a-z],w/w/g|sed s/[a-z],r/r/g|sed s/[a-z],n/n/g

This is only there to avoid another possible error which would be a leading w without ID for a way. This is also done for nodes and relations.

1st. night getting use to mapping

Posted by Hdrider03 on 18 November 2015 in English (English)

Have no Idea where I went in the neighborhood, but I am getting use to the navigation tools and such, I really love this technology, it really surprised me to see how far it's came in my life time, I will be more attentive tomorrow with mapping to friends and Clients locations and list good notes.

It's rather late and I need to sleep.

Dealing with incorrect tags in Africa

Posted by NicEd on 17 November 2015 in English (English)

So today I spent quite some time correcting tags of three major roads in Luanda ANG, Kitwe/Ndola ZAM and Windhoek NAM. The three roads were tagged as freeways.

While they may kind of look like freeways, nowhere along the extension of these roads is there proper signage identifying them as such; the T3 dual carriageway from Ndola to Kitwe has many 60km/h limit zones, which automatically takes the right from that road being called a freeway.

The Windhoek B1 Western Bypass has all the structure to be tagged as freeway; however, freeway signs in Southern Africa are blue (K53 code); B1 has all its signage in green. Often authorities refrain from taking that step so that slower traffic is not restricted from using the road under the access restrictions that apply to motorways. This is the case for Windhoek.

The unnumbered road in Luanda is de facto an expressway, and it actually carries the name in Portuguese, which is Via Expressa. Also, the very intricate road configuration in Angola makes it rather difficult to always tag roads correctly, since the passing (inner) lane is also the exit lane to U-turns and other road links, which exist in a great number on most primary roads in Luanda and other cities. Non-observed speed limits range from 30km/h to 90km/h, so this factor alone doesn't allow any of these roads to be tagged as freeways.

To the taggers who were there before me. Please understand that I corrected all your tags (about 200 of them), and this alone would possibly trigger an edit war; I strongly discourage you from doing so. If you have any enquiry about the last edits of mine, please drop a comment on this entry, or PM me.

#Spotted - 2

Posted by PlaneMad on 17 November 2015 in English (English)
  1. Yeti footprints screen shot 2015-10-28 at 10 58 10 am

  2. Distorted building screen shot 2015-11-02 at 10 12 35 am

3. screen shot 2015-11-03 at 12 21 07 pm

< Previous

Hadjer Lamis, Chad - Tracing guide

Posted by IvanGayton on 17 November 2015 in English (English)

Overall goals

The Hadjer Lamis area is very poor, and there is an unusual burden of disease and malnutrition amongst the population which contributes to high mortality in children under five years old. In order to better understand, assess, and respond to this, we need to know more about the population.

We are mapping villages and taking their names on the ground, but identifying all of the inhabited areas and counting the structures is much more efficient from aerial photos. Knowing where all of the villages are scattered through the savanna helps us to map them, and counting the buildings within each village gives us a quick and fairly accurate method to estimate population (important to understand the spread of disease and identify areas of highest need). Perhaps surprisingly, structure counts are often more accurate than asking how many people live in the villages.

The tasks at hand are:

  • Find all of the villages in the area, and draw an area around them, tagging each as Land use, Residential.

  • Count the structures in each village. This can either be by tracing all of them as polygons and tagging them as Building, or by simply counting them and adding a tag Structures with the appropriate number.

  • Trace the tracks and/or roads between the villages.

Village structure

Settlements in this part of the world are generally organised into extended family compounds, each containing a number of small shelters and often a few crops. You can see the outlines of the compounds as dark lines dividing the village in to smaller sections. The villages are generally more or less circular.

Overview of Absoufa village

This village (Absoufa) is quite typical of the villages in the area. Here's what a little part of it looks like on the ground.

A small part of Absoufa

Villages much like this are scattered all over the landscape in Hadjer Lamis. It is difficult to find them all on the ground, as even the local people do not necessarily know all of the locations of all of the villages! If they are already traced, it is much easier for our field teams to find the villages to tag them with the appropriate local names and other information.

Try to trace around all of the compounds, not just the houses; the compounds often extend well past the inner circle of houses but are definitely part of the village.

Counting versus tracing houses

It is much faster to simply count every house than to trace them all. However, it is rather difficult to count accurately, especially when it is not immediately obvious which buildings exist and which are shadows, rocks, wells, trees, or other features. Furthermore, it is hard to verify that the count is correct (verification takes at least as much time as counting in the first place), and it is hard to maintain consistency between mappers (some people may count a ring-like structure which may be an old, collapsed house, while others may exclude these from the count). If all buildings/structures are traced, validators can more easily see what is consistently counted or not.

If you plan to simply count the structures, please add the following tag to the village polygon: Structures - 42 (or however many structures you counted). Do so in ID editor simply by clicking on the village polygon, hitting the + button in the 'all tags' section on the left, typing Structures into the left-hand box and the appropriate number into the right-hand box.

If, on the other hand, you are willing and able to trace all of the structures, don't worry about counting them, we can do so automatically from the tracing you've done!


There are two basic types of houses here: round huts, often called Tukuls, and rectangular buildings. All are made of some combination of mud and straw (in some cases the straw has been pre-processed by donkeys or cows, making it stickier).

Tukul and rectangular house

The tukuls are easy to spot from the aerial imagery. They are round, with a distinctive central point where the roof peaks. They look a little bit like, well, um, a rounded mound with a darker-coloured point at the top centre... you know, like a mushroom cap.

Peaked roof

Please simply tag all structures as "building". There is a distinction between "house" and other types of building, but it's incredibly difficult to tell the difference from an aerial photo, so best to simply leave them as "building" for now.

Peaked roof

Peaked roof

Peaked roof

The rectangular houses may have a thatched roof or a corrugated metal roof. A metal roof is usually quite obvious from the aerial photo as it reflects a lot of light. In general, the metal-roofed buildings are more likely to be important buildings such as a mosque, chief's home/office, or health clinic. If you see an obvious metal roof, you can add a tag for roof:material - metal.

Some of the buildings may be for storage of grains or animals (i.e. chicken coops). You can't tell from the aerial photo, so don't worry about it! Just trace all of the standing buildings you can see. The primary goal of the building tracing is to estimate population, and we can do this simply by multiplying the number of structures or roof area by a constant determined by surveys we do on the ground.

annotated village

It is fairly common to see a faint ring or rectangle where a building once existed (mud and thatch homes do not last forever). It is best to count only currently standing structure, as this is most likely to correspond to the actual population. However, in the event that you can't tell whether the building is still there or not, please trace it! When in doubt, add the feature. It's easier to remove it than to find a missed one.


Unlike areas further south in Africa, where villages usually consist of a collection of homes without much internal separation, villages in Hadjer Lamis are basically organised by family compounds. Each compound is surrounded by a fence of mud, wood, or brush, and contains several buildings (sometimes including grain storage buildings as well as houses). Many compounds also include some cropland, in what is effectively a small farm or large garden.

compound wall

These fences really define the internal structure of the villages.

compound wall

Sometimes buildings are integrated into the compound wall; often you'll see that a rectangular building shares an outside wall with the compound perimeter.

There is no existing default tag for "compound" in OpenStreetMap. Therefore, when they are mapped as an Area and simply tagged "compound", they do not appear in the OSM map (though they are present in the data). For this reason, until we are able to resolve this, we are not tracing the compounds in the current task. However, please learn to recognise the compounds as they are part of the village; if you only trace around the houses the village perimeter will appear smaller than it actually is.


There are very few roads in this area that resemble Western-style roads. While there is one main paved highway through the region, almost all roads are dirt tracks. For that matter, most of them are temporary; during the dry season vehicles can pass more or less anywhere and don't need to follow a specific road. Whichever route is most used during the dry season then tends not to grow many plants during the rainy season, so it becomes the default road for that rainy season! As a result, you'll often see a bunch of intertwining paths between major villages (especially if the imagery is taken during the dry season), where each car has taken its own slight variation on the route.

So how do you define a road as a line on a map when there's no single permanent road?

This requires a certain amount of judgement. The first thing, obviously, is to see where there are actual tracks. Once you've found a track, look to see if there are other tracks nearby, especially larger ones (or groups of tracks) that may be more likely to be the "official" road. Finally, zoom out, take a look around, and see if the road actually goes somewhere! A very good clue that a track, or set of tracks, is actually an often-travelled road is if it connects two settlements, or connects a village to a seasonal watercourse (where there may be a well where people fetch water). If, on the other hand, a track goes out from a village and ends in a field somewhere, it's quite likely that it's nothing more than the fresh track of a single donkey cart whose owner travelled to their field on the day the satellite photo was taken.

A rough guide to road classification levels:

  • if it's paved, it's a primary road. In fact, it's pretty much national highway #1.

National Highway number 1

  • If it's a clearly defined single road with permanent-looking sides, and goes between large population centres (i.e. from a town to a large village), it's a secondary road.

secondary road untraced

secondary road untraced

  • If it's a multi-tracked road that obviously sees a lot of passage, and goes between villages, it's a tertiary road.

untraced tertiary road

untraced tertiary road

  • If it's a single track, but clearly goes somewhere interesting (like another village, or an obvious water point, or to a larger road), it's a track.

  • If it's a single track and doesn't obviously go anywhere interesting, it's (at best) a Path, but more likely it's just where somebody happened to go with their donkey cart recently; don't bother tracing it.

  • A path within a village, particularly if it obviously links compounds or large features like water points, or connects to a tertiary road, it might be worth tracing and labelling Path. However, use your judgement in doing this; while it might make the map of a given village a bit more clear it doesn't serve much purpose in terms of identifying population or facilitating humanitarian work.

Location: Ndjamena - Bokoro - Mongo National Road, Hadjer-Lamis Region, Chad

Japan road alignment - Taking it further

Posted by _yog on 16 November 2015 in English (English)

Recent diary entries showed that there was some love needed on OSM data in Japan, as a casual mapper, I wanted to work a bit on my JOSM "skills" and I thought this data alignment task would be a useful practice field.

The instructions were to realign main road axis but looking further than the filter, it appeared that the task was a bit wider than that.

Here are the work-flow I adopted after a few hours of armchair mapping. Hopefully, it'll be useful for someone else. Feel free to correct any mistakes I could have written.



First thing first, TeachOSM is giving a tracing source on its instruction page. As long as you use the task manager it will load this imagery for you, but what if you want to go back on a certain area after it has been locked ?

In JOSM, go to the preferences/WMS TMS tab then add a new TMS where you need to fill the source url in the corresponding fields.{z}/{x}/{y}.jpg

JOSM - new TMS

Once added, the new GSI Japan imagery will be available in JOSM's Imagery menu.


I found the general luminosity of JOSM too bright. To soothe eye pain, dim the luminosity of the imagery layer. It also increases contrast and helps data readability. This can be done by playing with Gamma and Transparency setting on JOSM layer panel.

JOSM - Luminosity/Gamma


Data in Japan REALLY need some love...

I'm usually mapping in the UK, mostly London, where the data is of good quality. This became my standard and I obviously tried to match it.


In some areas, a lot of straight roads or streets are actually scattered with intermediate redundant points.

Easy fix but time consuming.

Shift+Y is your friend.



Many junctions between roads are made of short segments that can be easily fixed: several segments of road can be combined into a single one by selecting them and pressing C.

Once combined, redundant nodes can be merged into a single one to simplify the network. M is the dedicated shortcut. JOSM - C and M

You might be prompted to reverse path direction. For bi directional roads, direction does not matter and you can simply accept, for unidirectional roads, streams or rivers, make sure the direction is matching real life.

A path direction can be reversed via the R key. JOSM - Reversed

If some subpaths are missing tags, a dialog will open asking you what to do. In the following case, only the name is missing and it can be automatically added for you.

Other scenario might request you to chose between conflicting tags such as road type (residential / unclassified)

JOSM - C, M and rename JOSM - fix cross section

This can also help fixing misconnected paths



Finally, ice the cake by aligning road connections via the L key


These simple key combinations, a bit of free time thanks to the lovely UK weather, and here are 36 950 edited nodes in 25 changesets. There is a lot more to do and any help will be much appreciated :)

The corresponding Overpass turbo, relatively heavy to load. Overpass

JOSM is relatively easy to get around and as many have done before, I encourage anyone to give it a go.

Location: 蒲郡碧南線, Nishio, Nukata, Aichi, Chubu Region, Japan

HOT Voting Member Nomination

Posted by michael63 on 16 November 2015 in English (English)

How I got in touch with HOT

Having always been interested in maps some of my favourite activities apart from hiking is producing topographic style maps from OSM data particularly for areas where hardly anything else is available. When I had a couple of months time available while changing my job about three years ago I wanted to give something back to OSM from where I got so many useful data for free.

Being a software engineer I did not simply want to contribute to some of the tools involved but rather spend my spare time doing something different. Browsing the wiki I read about HOT. I was instantaneously fascinated by the idea to combine the expansion of the database with another goal - provide help to communities in urgent need for this. And the concept of micro-tasking made the start quite easy: you can contribute basically any amount of time available.

After having spent one year with the usual mapping of roads and buildings in the beginning I turned my attention to more difficult tasks and thus got in touch with Séverin Menard and his activation in CAR. This should be the first in a series of import tasks where I contributed and extended my skills.

Apart from directly working on our data I was working together with Nick Allen on learnOSM translating large parts of existing documents to German while also updating some existing English documentation.

What HOT means to me

HOT is an opportunity to provide assistance to people in need in various areas of the world even if one is not able to provide help on site. It offers a much more direct involvement than just donating money: after a couple of days into an activation, white spots on a map turn into a maze of tracks and roads making sure that the vulnerable people on the ground can be given assistance.

One of the core values for me is that people with very different background (both in terms of professional experience/education as well as geographic origin and cultural tradition) are working together for a common goal and always willing to help each other. The community is as diverse as are the tasks to be managed. Local communities can gather and verify data on the ground and train new contributors while others working remotely like me can improve base data, take care of documentation or communication.

Irrespective of the amount of technical expertise and available time, everyone can contribute to the common goal, these contributions will be welcome and in the end result in better maps for places where they are desperately needed.

Future plans

Based on my professional experience as a software developer I know that quality assurance is often neglected (as is documentation) but nevertheless of utmost importance. Having gained experience in mapping I started to validate in a number of projects. It soon became obvious to me that new contributors often make the same systematic errors again and again or simply get things wrong because they are not aware of local conditions in a region (e.g. classification of highways).

The humanitarian partners who rely on the data expect a high degree of accuracy in the data provided by HOT. If HOT is to keep its reputation we will have to make sure that the data collected in an activation are validated by someone with a minimum degree of experience and responsibility. If data generated by a contributor are clearly wrong then this must be communicated in a way that it is not perceived as plain criticism but as constructive guidance for improvement. We can not afford to deter inexperienced contributors by harsh criticism but need to keep them going and help them. My personal experience so far is extremely positive: the more detailed I explained errors they made and how to avoid them in future the more enthusiastic was their response often connected with request for further guidance.

The activations see an increasing number of new contributors which is amazing but In my opinion also causes one of the challenges for HOT: maintain the quality of the data with a growing number of contributors, many of them with little mapping experience.

I would like to see our documentation/guidelines on validation expanded. I also see a need to include feedback from validation in our existing documentation for contributors. This could happen e.g. in the framework of learnOSM. Such a loop will in the end improve the quality of our mapping.

Why become a voting member?

I would consider my election as a recognition of my contributions delivered so far and even more as a motivation and obligation to serve even better in future. I already outlined my ideas concerning data quality and related documentation. I feel that it is an essential goal for the future development of HOT and thus connected with the responsibilities of a voting member.

Fixing Jakarta's boundaries (Part I)

Posted by capiscuas on 16 November 2015 in English (English)

After having announced in the Indonesia and Imports mailing list about my intentions of fixing the current administrative boundaries in Jakarta, capital of Indonesia.

So the first I did was to download the boundary:administrative ways in Jakarta area, by using the following Overpass API rule while downloading in JOSM.

(way["boundary"="administrative"];node(w); way(bn);); out meta;

Total boundary:administrative ways: 7809 of admin_level = 9 ways = 5082 of admin_level = 8 ways = 2717

I analyze the data and soon realize that there is a lot of overlapping ways, unjoined nodes with similar coordinates, and some areas that contain ways of admin_level=9 doesn't have the father way of admin_level=8

I have prepared an script to take the highest admin_level ways, split their ways into segments and create as many boundary relations hierarchically as possible, for example, in this case, I can create the boundary relation of admin_level=8 by using the external borders of those relations with admin_level=9, and so on for the admin_level=7, etc... I will explain this algorithm in the next post when I release the script to the public.

My first task was to prepare the data(offline) before creating those relations. Therefore I had to deal with those duplicated nodes with exact same coordinates.

By using the following python script I eliminated the duplicity and joined all the duplicated nodes at once. (this task is equivalent to selecting one by one each of the nodes and clicking the 'Merge nodes' tool of JOSM), but you don't want to waste that much time with 77657 nodes.

After executing the script, the total of nodes become 74936, so it joined almost 2700 nodes and we reduced the size of the OSM file a bit.

The second task was to get rid of those ways of admin_level=8 that overlap over those ways of admin_level=9 inside. In order to find out these duplicates, I made another python script(see but this time customized for the Indonesian boundary tags(you can change them to fit for your country or area context, you just need to understand the script).

Here is the result(the blue areas are those redundant level-8 ways that can be deleted in our local OSM to be ignored later on when creating the final boundary relations).

Keep tuned for the next post with the final conversion to boundary relations. Feedback wanted!

Location: Jalan Budi Kemuliaan 2, RW 04, Jakarta Special Capital Region, 10160, Indonesia

Big Shake-Up of Sheffield's Buses

Posted by Paul Berry on 16 November 2015 in English (English)

As of the 1st November, there's been a big shake-up of Sheffield bus routes and service numbers. A cursory inspection shows a lot of the routes renumbered so updating should be quick but there are also likely to be some routes revised or cut back so this is going to create further work for OSM contributors!

Location: Moorhead, Saint Vincent's, Sheffield, Yorkshire and the Humber, England, S14, United Kingdom

Grass&Green for better grass classification and understanding

Posted by grass_and_green on 16 November 2015 in English (English)

Dear All,

Grass&Green Still improve the classification quality of grass-related features in OSM @ Germany We still need more analysis and feedback from you all to improve the tool and afterwards apply the methodologies in other locations. Here, are some results

It was village_green only. Which is in some location in Germany is not familiar term. Our contributors labeled it as "Park". It has been checked with 14 contributors. Alt text

The next was only grass with fence, the contributors with our tool. make it "Graden" which is more expressive information than grass with fence.It was checked by 5 contributors. Alt text

The next was labeled as "Park", however its characteristics is far from being park for amusements and entertainment. Out tool correct it to the reasonable classification as "Garden" Alt text

Finally, we still need your contributions. It is added to your editing history and scores. Just Visit Grass&Green and login by your OSM account. Alt text

then, Contribute simply Alt text

Thanks for all previous and coming contributors

Tracing guide for villages in Hadjer Lamis

Posted by IvanGayton on 16 November 2015 in English (English)


Location: Absoufa, Hadjer-Lamis Region, Chad

OpenStreetMap Carto Complexity

Posted by pnorman on 16 November 2015 in English (English)

This is a repost from my blog

I often refer to OpenStreetMap Carto as the largest most complex open multi-contributor map style, but what does that mean?

Broken down, it means

  • It’s the largest open stylesheet. If you measure in code size, features rendered, or complexity, nothing else is close;

  • It’s the largest multi-contributor map style that doesn’t have a company dictating what is worked on. This means we get merge conflicts. They got so bad we changed the technology we use to define layers to make them solvable; and

  • It’s the largest style using OpenStreetMap data. Some proprietary styles like OpenCycleMap, MapQuest Open, and Mapbox Streets are complex, but none of them render the range of features we do.

This complexity didn’t come about out of nowhere. It’s been building since contributions shot up in October 2014. This is when we introduced YAML layer definitions, making the style much easier to edit and streamlined the feature merge process.

The style is large enough that no one person can understand it all. I know I can’t and I’m a maintainer. There are too many parts, and too many interdependencies between them. How does this style stack up against other big Mapnik styles which show a range of features? Styles like OpenStreetMap "FR" Carto and OpenStreetMap Carto German which try to showcase all of OSM data are forked versions of OpenStreetMap Carto, but there are some truly independent styles we can look at.

Not all styles use YAML layers, so to make the measurements consistent I processed layers defined in JSON through a bit of python:

python -c 'import sys, yaml, json; print yaml.safe_dump(json.load(sys.stdin))'

This is the reverse of osm-carto and gives the layers in the same YAML form.

Stamen have taken part of the design of CartoDB Basemaps as well as their own maps, and all three make use of some variation of High Road which simplifies you to only ever see three road classifications at a zoom, and what they are changes with zoom level.

Mapbox Streets’ heavy use of SQL is unusual. They are using triggers to post-process osm2pgsql data into multiple tables, simplify, and transform tagging. This novel approach probably brings with it interesting maintenance challenges, and normally I’d recommend using Imposm or osm2pgsql lua transforms. uses 285 lines of Lua to have one of the most sophisticated handling of cycle-related tags for rendering surface quality, and it would take significantly more SQL to do the same work in layer queries.

Surprisingly, Mapnik XML line counts are comparable to CartoCSS line counts, so we can look at the Mapnik XML stylesheet from 2012, MapQuest Open, and OpenTopoMap, three full-featured Mapnik XML stylesheets.

What’s shocking is the linecount of osm-carto compared to everything else. The next three most complex CartoCSS styles have about the same number of lines combined.

The choice of imposm vs osm2pgsql or the use of intermediate vector tiles don't seem to change style complexity.

Thanks for Richard Fairhurst, AJ Ashton, and Andy Allan for numbers for their stylesheets. Komяpa provided some MapCSS numbers, but I ultimately didn’t use them since I wasn’t sure MapCSS and CartoCSS linecounts were comparable.

Mapping on the field at Mapbox

Posted by Arunasank on 15 November 2015 in English (English)


As part of the on-boarding process at Mapbox, Sanjay, Abhishek and me set out to map levels and types of buildings around the Mapbox office in Indiranagar with help from Maning. The general idea was to micro map using field papers to identify the number of levels in each building and also classify buildings more appropriately under building=commercial or building=residential tags instead of classifying them under the more generic building=yes tag. Identifying levels on buildings would also make the 3D map of Indiranagar vastly denser.

Armed with field papers and pens, we entered micro-mapping territory. Just before splitting and heading out by ourselves, Maning suggested using a <number-of-levels>,<building-type> code for each building, so we wouldn't overcrowd our field papers with writing. This would mean that for a residential building with three levels, we use 3,R. Walking around, with passersby looking at us queerly was interesting to say the least!

Maning's field paper

In spite of using field papers with help from a really experienced mapper, we still had to think about a lot of things - some houses with terraces had a small outhouse constructed on one side of the terrace, which wouldn't count as an additional level. It was the same story with residential houses that have a terrace garden with an asbestos sheet covering the garden - the garden wouldn't count as a level. We also had trouble classifying the buildings since the floors in several buildings were equally divided between residential and commercial establishments. It was also interesting to note that the number of levels in a building is not directly proportional to the height of a building - buildings with two levels may sometimes be taller than buildings with 3 levels - which wouldn't be represented accurately on a 3D map.

Field papers are extremely useful during the mapping process because they automatically georectify the map layer and overlay it on the satellite imagery when being imported. This is not the case in traditional mapping where one has to manually do this. This is a huge benefit because it saves time and prevents accidental errors while tagging buildings. It is also extremely easy to import field papers into JOSM and overlay them over the satellite imagery of the area being mapped.

You can see a better visualised Indiranagar by PlaneMad on overpass after our field mapping trip. Indiranagar on overpass

The results in 3D are available on F4 Map

Indiranagar on F4 Maps

email rejected

Posted by michsim on 15 November 2015 in English (English)

Can not purchase download of UK map as the shop says "please enter a valid email" the email I enter is definitely valid? Is this a problem someone else encountered. Thank you for any help. Michel

JR Gyoda Station

Posted by Priscilla73 on 15 November 2015 in English (English)
  • Platform: The platform was first modified to meet only with my GPS traces. I walked on the edges of the platfofrm twice at an interval of a few hours. However, when you looked at other GPS traces of nearby roads and JR Takasaki line, it was apparently shifted northeast. Even a section was overlapped with the inbound track. Eventually, I aligned the position with nearby objects such as the station building and other GPS traces. It told me that GPS always has some degree of error even if it's laid under an open sky. Just a few traces may not be enough to position a map feature.
  • Station building: The shape of the station building was drawn based on Bing images and its position was aligned based on GPS data. On-site survey also helped greatly.
  • Tracks: Train cars approach the platform very closely. This indicates the center of the track is apart from the platform edge half the width of the cars. The E231 series are currently used for Takasaki line whose width is 2.950 meters, which means the track is roughly 1.5 meters away from the platform edge.


Here's a quick summary that I obtained through my acitivities to draw on the map the map features linked to JR Gyoda Station.

  • Shape and angle: Bing images will surely help.
  • Position (coordinate): As it's often said, Bing may not provide an accurate position. Therefore, GPS should be used to locate the map feature. However, more than several traces may be needed because GPS has some degree of error even if it's placed under good condition. It's also important to look at GPS traces of nearly objects such as roads. It surely helps good alignment of the map feature. Sometimes, physical measurement of the length helps. I walk on the path and count my footsteps, which gives me a good estimate.
Location: 138, Gyōda, 比企郡, Saitama, Kanto, 3600031, Japan

Humanitarian OpenStreetMap Team Voting Member Nomination 2015

Posted by Kateregga1 on 14 November 2015 in English (English)

How did you become involved in HOT?

I got involved in HOT in March 2015 as a Regional OSM Trainer for the Tanzania project with Mr. Jeff Haack. This came after OpenStreetMap work done with Mapping day Uganda organizing mapping events and training university students in different parts of the country on how to map and using the HOT tasking manager to help when disaster occurs elsewhere in the world.

In June 2015 I was lucky to be one of the scholarship winners for State of the Map US 2015 in New York. This gave me an opportunity to learn more about how HOT operates through attending HOT meetings at conference and sharing experiences with several people involved in HOT.

Could you tell us about your involvement in HOT, mapping and/or humanitarian response?

I am currently involved in HOT as the Lead Mapping Supervisor working on Community Mapping for Flood Resilience - Ramani Huria in Dar es Salaam Tanzania. My work involves supervising and coordinating all mapping activities. We have trained over 150 university students who are all part of the HOT community in Tanzania now.

In June 2015, I was one of the participants who attended the HOT Activation Curriculum workshop in Dar es Salaam. At the workshop I was able to meet with other 13 HOT people from different parts of Africa where we were able to share experiences on what HOT means to everyone and what we would like to see happen in the future especially for Africa.

What does HOT mean to you?

For me HOT is one of the big inspirations for people to map. It is human nature to offer help to anyone who is affected by disaster, mapping and organising mapathons is the only way through which some of us can give the much needed help. But also being part of HOT gives very many OpenStreetMappers a sense of belonging to something special that is being done for the map that we all love.

Why do you want to be a voting member?

Becoming a HOT voting member will give me an opportunity to have a voice within the global community to be able to contribute to its growth. A lot of things happen behind doors to make what the rest of the world see as HOT, it will be an honor for me to be able to contribute to this process as a voting member.

As a voting member of HOT what do you see as your most important responsibility?

As a voting member, my most important responsibility will be to voice the opinions of the growing community in Eastern Africa in matters affecting the corporation and helping it grow by openly expressing my point of view on different issues whenever necessary. Also it will be my responsibility to be an ambassador of HOT in Africa by promoting the aims and objectives of the corporation in whichever way that I can.

How do you plan to be involved in HOT as a voting member?

As a voting my member my role will be to participate in the voting process by supporting initiatives that are important for the growth of the corporation. In addition I also hope to take part actively in future activations especially in Africa basing on lessons learned from the HOT activation workshop that was organized for us in June 2015 in Dar es Salaam Tanzania.

What do you see as HOT's greatest challenge and how do you plan to help HOT meet that challenge?

The greatest challenge I can see for HOT is finding a reasonable balance between community development, technical projects and collaborative mapping. From my experience gained on working on community mapping for flood resilience in Dar es Salaam, I will be able to contribute by giving my opinion whenever required on the course of direction to take on any project that arises.

‍‍ನಮ್ಮೂರು ‍‍ಹಾಗೂ ಸುತ್ತಮುತ್ತಲಿನ ‍ಉಚಿತ ಮ್ಯಾಪ್ ‍ ‍

Posted by Chetan_Gowda on 14 November 2015 in English (English)

‍‍ನ‍ಮ್ಮೂರು ಹಾಸನ ಜಿಲ್ಲೆಯಿಂದ ಸುಮಾರು 12 ‍ಕಿಲೋ ಮೀಟರ್ ‍ದೂರದಲ್ಲಿ ಉಂಟು. ಹೆಸರು ಕೌಶಿಕ ಹಿರಿಹಳ್ಳಿ ಎಂದು. ಸುಮಾರು 70-80 ಮನೆಗಳಿರಬಹುದು. ‍ಹಳ್ಳಿಗೆ ಬೇಕಾದ ಎಲ್ಲ ಸೌಕರ್ಯಗಳು ಇಲ್ಲಿ ಲಬ್ಯ. ‍‍‍

ಊರಿನ ಆಚೆ ಓಂದು ‍ಪ್ರೌಡ‍ಶಾಲೆ, ಆರೋಗ್ಯ ಕೇಂದ್ರ, ಪಶು ಆಸ್ಪತ್ರೆ ಕಾಣಬಹುದು. ಒಪನ್ ಸ್ತ್ರೀಟ್ ಮ್ಯಾಪ್ ನಿಂದ ನಮ್ಮ ಊರಿನ ಏಲ್ಲಾ ತರಹದ ‍ಅಂಶಗಳನ್ನು ಗಮನಿಸಬಹುದು. ಯಾವ ಯಾವ ‍ಪ್ರದೇಶಗಳ‍ಲ್ಲಿ ಹೊಲಗಳು, ಕೆರೆ ಬಾವಿಗಳು, ಬಸ್ ‍‍‍ನಿಲ್ದಾಣ‍‍ಗಳು, ಮನೆಗಳು, ದೇವಸ್ಥಾನಗಳು ಹಾಗೂ ಮರಗಳು ಇದ್ದಾವೆ ಎಂದು ಪರಿಪೂಣರ್ ವಾಗಿ ನೋಡಬಹುದು.

‍ಎಲ್ಲ ಮನೆಗಳನ್ನು 3D ಯಲ್ಲೂ ಸಹ ಕಾಣಬಹುದು.

screen shot 2015-11-04 at 5 03 58 pm screen shot 2015-11-04 at 5 04 13 pm screen shot 2015-11-14 at 9 35 52 pm screen shot 2015-11-14 at 9 36 27 pm

ಇದೇ ತರಹದ ಹಳ್ಳಿಗಳು ನಮ್ಮ ಭಾರತ ದೇಶದಲ್ಲಿ ಸುಮಾರು 6 ಲಕ್ಶ್ಯಕ್ಕು ಮಿಗಿಲಾಗಿ ಇರುವುದು ಒಂದು ಅಚ್ಚರಿ. ‍ಆದ್ದರಿಂದ OSM ಸಮುದಾಯದ ಜೊತೆಗೂಡಿ ನಮ್ಮ ಅಕ್ಕ ಪಕ್ಕ ಹಳ್ಳಿಗಳು, ತಾಲೂಕುಗಳು, ಜಿಲ್ಲೆಗಳು, ರಾಜ್ಯಗಳು ಹಾಗೂ ಇಡಿ ಭಾರತವನ್ನು ಮ್ಯಾಪಿಂಗ್ ಮಾಡುವುದು ತುಂಬಾ ಮುಖ್ಯಾವಾಗಿದೆ. ಬಹು ಮುಖ್ಯಾವಾಗಿ ಮ್ಯಾಪ್ ಗಳು ಚುನಾವಣೆ, ಬರಪೀಡಿತ, ‍‍ಕಾಯಿಲೆಪೀಡಿತ ಜಾಗಗಳನ್ನು ಕಂಡು ಹಿಡಿವಲ್ಲಿ ಬಹಳ ಉಪಯೋಗಿಕವಾಗಿವೆ. ಅದಲ್ಲದೆ ಸರ್ಕಾರವು ಕೂಡ ಈ ಮ್ಯಾಪನ್ನು ಮುಂದೊಂದು ದಿನ ಉಪಯೋಗ ಮಾಡುವ ಸಂಗತಿಗಳು ಬರಬಹುದು ಎಂಬ ಅನಿಸಿಕೆ ನನ್ನದು.

ಆದ್ದರಿಂದ ಬನ್ನಿ OSM ಅನ್ನು ಉತ್ತಮಗೊಳಿಸಲು ಕೈ ಜೋಡಿಸಿ.

ಕೆಲವು ಲಿಂಕ್ ಗಳು -

Location: Rangoli Halla, Hassan, Hasana taluk, Hassan district, Karnataka, 573201, India
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