Recent diary entries
I was surprised when I received an email confirmation of the scholarship to participate in the conference of SOTM 2017. It was the first time to participate in the international SOTM which was held in Aizuwakamatsu, Fukushima, Japan.
My application of talk SOTM 2017 was selected and I got an opportunity to present the OSM in Sri Lanka in the conference which has given me the opportunity to express my country circumstances of OSM activities and Importance of the OSM activities in Sri Lanka.
SOTM 2017 has given me an opportunity to meet other scholars and most important why I participated that it was to introduce the Sri Lankan OSM community activities and understand about the other OSM community.
I had a chance to meet other OSM community members, researchers, lecturers and other experts and I had wonderful days in Japan. I love Japan Community and their dedicate, punctuality, kind and ect.. if I have a chance to visit to Japan again definitely It will be a great opportunity.
I also plan to become a member of the OpenStreetMap Foundation, and form an OpenstreetMap foundation in Sri Lanka.
Finally I take this opportunity to thank to OpenstreetMap Foundation, Donors, Japan OpenStreetMap Foundation that they gave me the opportunity to participate in STOM 2017 Conference.
Since 1 or 2 years, I'm testing some low-cost GNSS receivers with RAW output. The goal is to get a cm accuracy. One way is to store the raw data, then post-process it with the open-source software RTKLIB. I had various fails and success and I finally find a point to place my own reference station, my "base" :
One test was to put the "rover" on my car go back to my home. RTKLIB gave me a solution with "FIX" for a big part of the record : orange is "float" and green is "fix" (best accuracy)
An interesting part is a new roundabout, too new to see it on any aerial picture :
Ok, but what about the accuracy ? So, zoom in, zoom in, ..... zoom more !! Each square is 1 cm. Yes, the accuracy is about 1.5 centimeters !!
RTKLIB gave me a very good accuracy, but is this real ? I can't answer for this individual point, but with the results I got on surveys points from the French national geographic institute (IGN), I think I can say that the accuracy should be at about 5 or 10 cm, as my base coordinates are not perfect.
RTK vs Aerial Imagery accuracy
We are in September 2017, and the IGN just published new aerial imagery, and they usually do a very very good job. Finally I can see the roundabout I draw on OpenStreetMap 1 year earlier.
Let's compare my recording and the pictures:
Hey ! Not bad !! Now I must train to drive with a centimeter accuracy :-)
OpenStreetMap database accuracy
I speak about gnss trace accuracy, aerial imagery accuracy, but what about OpenStreetMap accuracy ? I heard that with 7 decimals, the coordinates stored in the OpenStreetMap database get only a 10 cm accuracy. Don't you think that It'll be a problem sooner or later ?
Perhaps we should consider adding a 8th decimal ?
At zoom 19 inwards, everything but the roads turn brown. What is going on? How do I detect odd polygons like that?
waymarkedtrails.org, the site to show all things route related, has always taken care to try to put route relation members in a sensible order before displaying them. A couple of weeks ago this has changed. The site now assumes that the members of each relation are already in the correct order. The reason for that is simple: sorting route relations is hard.
Before explaining why sorting is hard, let me explain why order even matters. As long as you simply want to display the route on a map, the order is not important. Simply color each way in the relation to your liking and the route is nicely visible for a human reader. However, waymarkedtrails.org does a bit more than that. It displays an elevation profile and allows to download a GPX of the route, so you can put it onto your favourite mobile device. When the route is not sorted in the expected order, then the GPX is unusable for many applications, for example in Garmin Basecamp.
So why not sort the route automatically? On first sight, this seems to be a simple task. After all, a route should be a simple linear connection from A to B. Unfortunately, the real world is much more messy.
Even the most simple case of a linear route from A to B already has two solutions to the problem. The route may go from A to B or from B to A. In most cases the direction doesn't really matter but there are exceptions. Take a downhill mountain bike route, for example, or a nature trail with information panels that should be visited in the correct order.
Then there are loop routes which end at the point where they started. When sorting automatically there is no way to determine the starting point of the route. In both cases, we could add extra tagging to mark the start and end points. But why add the extra work when sorted route give the start and endpoints clearly at the beginning and end of the list?
Also, not all routes in OSM are strictly linear: there are routes with directional deviations. This can often be found in cycling routes which might go through oneway streets. Sometimes these deviations mapped with forward/backward roles but not always. Then there are routes that contain alternatives, side trips to lookout points and alternative access points.
waymarkedtrails could surely use some heuristics to get all these cases right most of the time but then there is no way to fix the decision if it gets it wrong. I think that is much better to leave the final decision about the order to the mapper.
Keeping your routes in the right order isn't too much work either. The JOSM relation editor is a very powerful tool when it comes to sorting relations. In the list of relations there is a column that immediately shows you the connectivity of your relation members. It can even handle directional deviations and roundabouts. Keeping an eye on the connectivity column is always a good idea while clicking your route together. It gives you immediate feedback when you've missed part of the route or created a small dangling end when you forgot to split a road. If you already have mapped your routes without sorting them, there is even a button to sort the members for you.
So, overall sorted routes are an advantage for everybody. They don't solve all problems with routes but they are a huge step forward in improving the quality.
Finally some numbers about the current state.
- 74337 linear routes already sorted (65 %)
- 14608 linear routes, not sorted (13 %)
- 24992 non-linear routes (22 %)
- 28020 linear routes already sorted (55 %)
- 5164 linear routes, not sorted (10 %)
- 17639 non-linear routes (35 %)
Much has been said about users of different OSM editor applications regarding their ability to respond to other users' feedback about their mapping. But why not let the data speak for themselves?
Here's a quick chart I made.
I used ChangesetMD to import data into Postgres database, where I did the analysis.
I like how easy it is to upload a GPS trace. Does it show directly on OSM? or is there another step to enter the new path into the main database?
Places to visit
After some tagging chat on the Italian ML it came to my attention that iD is setting crossing=zebra tags on crosswalks, a tag that is not documented as value for the crossing key, besides in the UK. As I believe that using different tags for the same thing - although not really harmful - makes everyone's lifes a bit more complicated, I thought I'd give them a hint, after all, usage of this tagging is still behind the longer standing established and documented one. So I created this issue: #4316.
It came up, there are already 3 tickets where the same issue had also been dismissed.
IMHO, we should take care that editing software proposes the same presets for the same objects and properties (not necessarily the same level of detail, or presets for the same things), because tag fragmentation is a burden on everyone. In this case it is very clear that crossing=zebra only came to significant use when it was added as a preset in iD in May 2014 (compare with the graph above).
On August 30th the Minsk OSM community together with the byGIS community celebrated the 13th anniversary of the OpenStreetMap maps. On this day the enthusiasts of cartography gathered at the meetup in the cozy Event Space hall. The program had four reports on various OpenStreetMap related themes:
Darafei Praliaskouski storied about those people who stand behind the site OpenStreetMap.org, how it functions and what can be done to make it work better. video
Evgen Bodunov told about the project "Mapzen Valhalla" video
Vitali Danilovich opened a heated discussion about the tagging of public transport in OSM video
And at the meeting, as on the right birthday, there was a birthday cake with the emblem of the Belarusian OpenStreetMap community!
Thanks to Kurban Bayram, I had a four-day weekend. Thanks to the preparations for the Asian Indoor and Martial Arts Games, central Ashgabat was closed to most traffic for all intents and purposes. So I stayed home and used the nascent gazetteer project to check for typographical errors and other misspellings in the OSM database for Ashgabat. I think I have caught all major typos and other errors.
I also began research into the historical names for the streets in this city, which in some cases have changed several times. To give you an idea of what's involved, here is the entry for Magtymguly, a major thoroughfare, which is now on its fifth name:
Magtymguly (2033) şaýoly
Mervskiy prospekt, Kuropatkinskiy prospekt, prospekt Svobody, prospekt Stalina.
Magtymguly Pyragy (1724-1807) was a Turkmen spiritual leader and philosophical poet who made significant efforts to secure independence and autonomy for his people in the 18th century. He is considered the greatest Turkmen poet, though he wrote in Arabic, Persian, and Chagatai, not in Turkmen. The original name of this street was Mervskiy prospekt as the street led eastward to the city of Merv (modern Mary). It was subsequently changed to Kuropatkinskiy prospekt to honor Russian General Aleksey Kuropatkin (1848-1925), who is credited with the victory over the Teke armies at the Battle of Gökdepe and from 1890 to 1898 was governor of the Transcaspian governate, effectively viceroy of Turkestan. He was Russia’s minister of war from 1898 to 1904, and was blamed for major Russian defeats in the Russo-Japanese War. During the Soviet period the street was named prospekt Svobody (Freedom Prospect) except for a period between 1953 and 1961 when it was renamed in honor of Iosif Stalin.
To name a few things in the above area:
residential roads tagged as motorways, primary or secondary
the same road went from motorway to service to residential to primary
island roads (not connected to rest of network)
roads ending just before the crossing
roads split in arbitrary segments all over the place
ways with a node for every half a metre length
And how about this?
Hi to All,
I am just wondering who recently partly erased tram lines again on Riga map and why/? I would like them back. Please.
As a big OSM passionate I will always remember year 2017, as it gave me the chance to join my first State of the Map conference: SotM 2017 in Aizu-Wakamatsu, Japan, on August 18-20, 2017. I was so lucky to be selected as a scholar, something I did not expect too much when I initially applied.
Even better, my application for a talk at SotM 2017 was also successful and I had the privilege of giving the presentation titled "OSM seen from a GIS researcher: experiences & perspectives". The purpose of this talk was to give an overview on the ongoing research trends on OSM. More in detail, I presented three applications I have worked on over the last couple of years: 1) a procedure to assess the quality of OSM road networks; 2) an analysis of OSM tagging patterns; and 3) a GIS application to convert OSM data into Land Use/Land Cover (LULC) maps. The slides are available here, while the live recording of the talk can be found here. I was really surprised that my talk has generated so much interest in the audience. I am used to take part in conferences, but I've never received so many photos during a talk! I hope my presentation has inspired many people :)
Another indelible memory from SotM 2017 is the official announcement I gave during a Plenary Session about the next State of the Map conference, that my university (Politecnico di Milano) will host on July 28-30, 2018 in Milan, Italy! It was amazing to make this announcement and get that long, long applause :)
But the most important reason why my participation to SotM 2017 has been great was the interaction with the community, as OSM is all about community! In addition to learning interesting news from the conference presentations (including some exciting ones given by HOT, Google, Apple and Facebook), I had the chance to physically meet many people who have done so much for OSM, to speak with other researchers, to ask questions to people who are doing great things for mapping in developing countries. Interacting with the organizing team was also great: you have made a wonderful job for this conference! Finally, I would like to thank the other scholars, with whom I spent not just a conference but a whole life experience in beautiful Japan. Guys, you will always be part of my history and my heart <3
Participating to SotM 2017 has further inspired me in collaborating for the benefit of OSM and its community. I sincerely hope to build up new collaborations (research, teaching and other kinds of projects) with many people I met, and to be able to help other people in the future with my knowledge and experience. I also plan to become a member of the OpenStreetMap Foundation, because I feel really grateful for the opportunity that was given to me and because I would like to be more involved at the community level.
All in all, this has been one of the best experiences of my life and once again I want to say a big thank to the OSM Foundation to make all this become possible!
A couple of weeks ago I launched an online survey aimed to collect demographic data about OSM contributors for a research project (funded by the University of Nottingham and the Engineering and Physical Sciences Research Council) concerned with gender biases in OSM. The survey has received a great response and I would like to send my thanks to all users who have so far participated.
However, more responses are needed (especially from women). I would therefore like to encourage any mappers, male and female, who have not yet participated, to consider doing so. There are only six questions and the survey takes less than a minute to complete, plus you could earn a £15 Amazon voucher for your time (apx. US$20).
The gender imbalance in OSM contributing is a recognised aspect of the project. The results of this survey will help to better understand the impact of this bias which could lead to more targeted strategies for widening participation. For more information and to complete the survey please visit:
NCN422 signs have appeared along Bath Road in Reading near Aldi and Lidl. Hopefully the section between Berkeley Avenue and Wokingham Borough, then the section between Wokingham centre and John Nike Way will follow soon.
As well as the previous entry, I'm also interested in the new development at Arborfield Green, together with the changes in Finchampstead - these should provide a link to Wokingham, and thus to the NCN422.
Current rendering order makes some bugs or problems with displaying data.
Examples: http://www.openstreetmap.org/#map=19/52.40698/16.96147 (piece of landuse=forest missing on landuse=grass) http://www.openstreetmap.org/#map=19/52.38318/16.95716 (piece of landuse=residential area protrudes over landuse=meadow)
I took and concider all tags from landuse=* , leisure=* , natural=* and tourism=* keys, which are allowed to map as areas, and analyze them, trying to order logically as layers.
*Waters and rock/ stones above green landcovers
*Higher plants above lower plants
*Physical coverage areas above areas describing terrain usage
*Treating parks and village greens as groups of unspecified plants
##Problem to solve:
An unavoidable direction which is OSM moving towards is more, and more precision. This means eg. covering an amenity=* areas by physical elements like buildings, grass or pitches. Then this cultural amenity=* or tourism=* areas becomes unvisible, and the only thing left is a label text. The same thing happens with parks overdrawn by certain types of plants, what causes loss of area park-status information, and loss of park borders information.
Examples: http://www.openstreetmap.org/way/66266360 (barely visible amenity=hospital) http://www.openstreetmap.org/#map=19/52.38752/16.94985 (amenity=kindergarden with grass pieces missing) http://www.openstreetmap.org/way/336645782 (barely visible amenity=school) http://www.openstreetmap.org/way/257507437 (barely visible leisure=park) http://www.openstreetmap.org/way/4685998 (barely visible leisure=park)
In my opinion, way_area key works good only between physical man-made landcover areas (group 5 on my list) and physical natural landcover areas (group 6). For example: small amenity=parking is rendered above large landuse=forest in the suburbs, but on the other hand, small landuse=grass pieces are rendered above larger amenity=parking area in the cities.
I very like the way, how landuse=military is rendered. That half-transparent color overlay (even without skew stripes) allows to show both things - physical landcover and area usage information - at once (example: http://www.openstreetmap.org/way/236175277 ). I think we should discuss using this method for all areas from groups 3 and 4, or, at least, discuss darker outlines like there are now around amenity=zoo areas (example: http://www.openstreetmap.org/way/480832184 )
I divided all of tags (treated only as areas, not points or labels) to 8 main groups. If something is listed in one string, it means that this elements are equal, and shouldn’t be mapped one on another. Proposed layers list begins from the highest to lowest level.
1.2.) Landuse=basin, Landuse=salt_pond, Leisure=swimming_pool, Natural=hot_spring, Natural=water
2) Rocks, stones etc.:
2.1) Natural=rock, Natural=stone
2.3) Natural=scree, Natural=shingle
3) Partly-physical, man-made areas:
3.1) Amenity=* (all amenity areas excluding 5.2. group), Landuse=cemetery, Landuse=military, Leisure=dog_park, Leisure=golf_course, Leisure=miniature_golf, Leisure=sports_centre, Tourism=*
4) Partly-physical, natural areas (unspecified type of landcover/ plants):
4.1) Landuse=village_green, Leisure=park
5) Physical, man-made landcovers:
5.1) Landuse=landfill, Leisure=fitness_station, Leisure=pitch, Leisure=playground, Leisure=stadium, Leisure=track
5.2) Amenity=bicycle_parking, Amenity=motorcycle_parking, Amenity=parking, Amenity=shelter, Amenity=taxi
In case of collision between groups 5 and 6: way_area key, taking the highest one tag from each group (if there are more than 2 areas overlapping)
6) Physical, natural landcovers (certain types of landcover/ plants):
6.1) Landuse=forest, Natural=wood
6.2) Landuse=orchard, Landuse=vineyard
6.4) Natural=heath, Natural=scrub
6.5) Landuse=meadow, Natural=grassland
6.6) Landuse=plant_nursery, Leisure=garden
6.9) Natural=beach, Natural=sand
7) Non-physical landuses:
7.1) Landuse=allotments, Landuse=brownfield, Landuse=commercial, Landuse=construction, Landuse=depot, Landuse=farmyland, Landuse=garages, Landuse=greenfield, Landuse=greenhouse_horticulture, Landuse=industrial, Landuse=port, Landuse=railway, Landuse=recreation_ground, Landuse=religious, Landuse=residential, Landuse=retail
8) Geographical regions:
8.1) Natural=bay, Natural=cape, Natural=fell
Some of these tags are not rendered now, but I included them on a list, because they could be rendered in a future (eg. Leisure=fitness_station). I’m not sure is it everything, so if I missed some rendered tag - let me know in a comment.
On 18-20 august I participated for the first time on State of the Map conference, which this year was held on Aizu-Wakamatsu Japan. One year ago I started to participate on events organized by Open Labs Albania, the only hackerspace in my country which promotes Free Open Source software and open data. They organize many events for different projects as Wikipedia, Fedora, Nextcloud, LibreOffice etc.
After a few days one of my friends Redon introduced me to OpenStreetMap, he helped me to make my fist changes on a map. And that was it, since that moment I started contributin to OpenStreetMap , firstly editing all the areas that I knew based on ground knowledge. At the beginning I may say that I was so enthusiastic that probably I might have made some mistakes as a newbie mapper that I was. Later I realised that it was important not only to contribute with data, but to try to add data with quality and try to be a good mapper.
I continued to participate on mapathons organized by members of Open Labs and after a few months I was able to co-organize with them. Despite mapping which I started with iD editor I started to search for other tools and so i found the featured desktop editor JOSM, which for me at the beginning was not so easy to use. My first presentation ever in public was on 14-th of May at OSCAL where I had a workshop for “Editing OpenStreetMap” and also an info booth. I continued to participate on mapathons organized by members of Open Labs and after a few months even I was able to co-organize with them. Despite mapping which I started with iD editor I started to search for other tools and so found the featured desktop editor JOSM, which for me at the beginning was not so easy to use.
This year was special because it was the first time for Albanian OSM community to be part of SOTM conference. Anisa from our hackerspace was there to, she had a talk “How to build an OSM community” on the first day 18 august, where she shares more details on how our community started.
When I applied to be part of the conference I was afraid that maybe I was not good enough to be there, and scared if I would be able to make a good presantation. I decided to give a try so I would be able to share all my knowledge and what I learnt intensively during the year. For me mapping was fun, I always liked geography, also traveling but hadn’t had many oportunities to travel until now. So I found maps a way of traveling around the world through mapping. Another thinks was that when started mapping I became more aware of whats was around me, noticed details that have always been there but I have not seen them, started to see the world from another perspective. Final result I was accepted to participate. I cried from happiness.
My presantation on State of the Map was Introduction to OpenStreetMap: Editing with iD editor and JOSM. I explained each of the editors the pros, cons and differences. For beginners it is easier to start with iD. JOSM has many extra features one of which is validation and offline using. Also it offers a lot of plugins. During the workshop I presented some of them like: building tools, wikipedia, utilsplugin2; As a future goal I want to make a guide in albanian language. Hope my workshop has been useful for the participant. I will continue to do more and improve my skills.
At SOTM2017 not only shared my knowledge but also learnt a lot from other participants. There were several different talks for community, mapping tools, gis software, experiences form users of other countries. Meeting all those people, hearing for their contributions motivated me even more. I saw that maps were more than a visualisation of our world, there is humanity, they can be as important as saving lives. This conference really affected me emocionally and also inspired me a lot. Now I want to do even more, have many things in my mind, need to set up a plan and continue contributing.
Thank you OSM foundation for the opportunity to be part of SOTM2017 and the wonderful organizing team for the great work. I enjoyed and learnt a lot there, also I spent great time with other participants.
I hope I can be part on other future conferences.