Mapper of the Month: Lauri Kytömaa (Finland)

- escada

Lauri's Heatmap

When and how did you discover OpenStreetMap?

I came across the Osm website in 2007, but I didn’t yet have a GPS and there was only landsat imagery, if I remember correctly. Near the end of 2008 I found a Garmin on sale, and remembered the osm site. After just a few gps tracks I was hooked, there was so much to improve in my home town, and in the meantime they had acquired the right to use Yahoo imagery, which was already usable, even if it had arbitrary distortions.

Quite soon after I had improved the road alignments near me, I realised the potential for entering all the possible interesting but non-obvious details of features, from start_date=* to taxon=* and turn:lanes=* to building:maintenance:operator=* (companies that to the daily maintenance of buildings leave a sticker on the front door). The possibilities are endless, and one can always find their own niche in Osm.

What do you map?

I used to map the areas I lived and studied in, on foot and in a car, going around taking hundreds of photos each time, and using several days to enter all the features I could possibly extract from the photos taken in just a few hours. In recent years, mapping has become more of a thing to do if I have spare time, but if I visit new places, I still try to spend some effort in taking good-for-mapping photos. And a traffic camera on our car has changed my mapping, new journeys get archived and I always have some videos I could go through.

How do you map?

I do almost all of my editing with JOSM. This year I’ve been fortunate to hit the start of the busy years of personal life, so surveys for the sake of surveying aren’t on the top of my to do list, but I try to incorporate surveying to any trips I take.

The gps on my current mobile phone seems worse than on the previous phone, but here in Finland we now have suitably licenced state provided imagery which is properly rectified. This means that I can usually get the details accurate enough with just imagery combined with photos/video, but I wouldn’t consider myself and armchair mapper, because mostly I don’t have the time to work on areas I haven’t visited in person recently.

How do you conduct your surveys?

In short: with a dog.

I’ve tried several methods over the years, and by now I believe I know how to choose the best method for each case with two main considerations: how much time I expect to have available for entering the data, and how soon I expect to revisit the area. Other things to consider are the availability of good aerial imagery and the level of detail already present.

If I were to do a survey of a limited area I hadn’t mapped previously, I’d still go for the method of gps + hundreds of photos; tilting the camera consistently to the left or the right when I shoot left or right to keep track of the direction. When doing a photoshoot survey, there’s no such thing as too much photos. I try to get a photo of all the house numbers, staircase letters, roadside amenities, traffic signs, building levels, lowered curbs and fences, to name just a few.

Where do you map?

Mostly I try to watch for local changes, and to slowly expand the somewhat complete areas of my favourite tags when walking the dog, but I also map on domestic and international trips, although then I usually don’t take detours anymore to get more data - that extra raw data would just consume disk space. I did spend a week or two tracing for the very first Haiti activation - being a student at that time it was possible - but after that I’ve traced maybe three squares from different HOT tasking manager jobs. So I’m mostly a local mapper, but I’ve touched the map in various places globally.

What is your biggest achievement as mapper?

Beside the moments when somebody proposed on the mailing lists, IRC or wiki, that we should map some feature others haven’t considered worthwile, and I can say “I mapped those like years ago, it’s quite fun to map those”. But if it has to be something I’ve entered on the map, the first thing that comes to mind has to be uninterrupted lit=yes/no tag on a 600 km journey - before I had video. Or the time I extrapolated houses in one area (which was then without aerial imagery) from hundreds of photos by calculating distance estimates from the sizes of the buildings in the photos, i.e. manual photogrammetry.

Why do you map? What motivates you?

Mapping in places where locals are just starting out with the details, I enjoy pushing their sense of map completeness by doing small areas way further than one would expect, so that mappers just might realise all the possibilities for detail and accuracy that can be achieved - and maybe they’ll figure out how the “first pass” mapping helps them to do the details later, as opposed to first drawing so crude data that it just gets in the way.

In the home territory keeping up to date with the changes is somewhat satisfying, but more fun can be found in mapping stuff that requires extra attention and deduction of facts from the surveyed details, like the district heating network, or the major water pipes. To do those as good as they can be, one has to be confident that they’ve mapped the whole area down to the last patch of pavement, and that they have entered all the details - and even then the map can be improved when the utility company digs up the street to do repairs.

What is the most difficult part of mapping?

It has to be letting go of good source data and moving on to the next picture or minute of video, when I have to choose between missing basic tags on the next source and detailed tags on the current.

What are your mapping plans for the near future?

I have weeks or months worth of traffic camera videos from our car, and just entering paved:date=* tags for this year’s freshly repaved roads would be near the top of the to do list - after finishing with the honeymoon photos from Santorini. Completing all the traffic signs for my home town Helsinki is a primary long term goal, another active mapper is almost finished with the house numbers and we have a shared svg file for tracking the areas we have claimed as traffic-signs-complete.

Do you have contact with other mappers?

I have only twice met other mappers in person. There’s an irc channel local to Finland, with about 40 active idlers - yet we do discuss there occasionally mapping and city planning issues (changes possibly coming up that should be mapped). In the past we concluded that mapping parties didn’t really work here: mappers meet, move around alone or in pairs to do their surveys, meet again shortly and go home to input their new data.

Only quite recently some seem to have been organising pub meetings, but so far I’ve thought that in general the time’s better spent doing actual mapping - especially now that other important real life activies require more attention than before.

Do you use OpenStreetMap yourself? How?

Virtually always when I have to get routing on my mobile phone, I use something based on OSM data. Occasionally, if I need to send map links to someone, I might link to the relevant element on the osm main website data layer. Sometimes I’ve used JOSM in a not-intented-way to draw some crude map illustrations (like comparisons of some areas) over an osm background, for the lack of a better software, and then saved those as cropped screenshots.

I used to use an old Nüvi for making tracks, but the battery on that died a long time ago; it did work for routing with converted osm data on international travels, in countries for which the device didn’t have any maps by default.

Years ago I started working on a Josm plugin, even got it working on a proof of concept stage, but soon after that somebody else released the far more advanced routing plugin. I’ve done a fair share of translating of Josm’s texts to Finnish, and I used to be quite active on the Osm wiki, both in English and Finnish, back when there were so little changes that I could read just about all changes each day through the recent changes page. Following the wiki started to take so much time that it was delaying mapping, so I had to virtually stop reading the wiki.

To conclude, is there anything else you want to mention?

OSM is about original research and local knowledge. If you can and want to keep it up to date, you should enter it. Other maps may have the same map features, but OSM knows more about everything.