HannesHH's Diary

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I discovered this nice little trick in JOSM the other day and thought I would share. At the moment I have to add loads of nodes to building polygons to tag housenumbers. If I would add each node separately the process would be:
For each node: Hit a, click to add the node, hit s, click elsewhere to unselect. This is a time waste and annoying.

There is a much quicker way, which comes especially handy if you have many nodes in one building or many buildings that need nodes in close proximity. Just keep adding nodes for all the entrances without unselecting. You will end up with a way but if you just delete the way (just hit d when you are done), the way will be gone but the nodes will stay where you added them.

(Don't forget to nicely distribute the nodes if appropriate (select the side of the building and hit b).)

Maybe this is well known around here already, but I just discovered it the other day:

Basically it goes like this:

Some corporation wants to provide cheap mobile internet. Buying a license for the normal spectrum would be expensive so they bought a license to transmit from satellites on some frequency. (I am not sure how this works with phones and how this frequency is different from the one they could acquired on normal ways.) Now, having such license for satellite transmission allows you to build terrestrial support transmitters, for example to cover areas of bad coverage. So now they can simply build base stations as "supplementary" stations and provide cheap internet.

What's the problem? The frequency band is right next to the GPS L1 spectrum, the spectrum our dear handheld GPS systems use. And since they broadcast "slightly" stronger than what we receive from the satellites, they ultimately jam the GPS frequencies if you get too close to such station, which in a city might be inevitable.

If only this was about a frequency close to L2, the frequency the military uses for their encrypted GPS signal... :-)

Smartphones with good GPS

Posted by HannesHH on 22 August 2010 in English (English).

I am planning to get a new mobile phone. Are there any Android/Maemo phones with good GPS builtin? I know some use AGPS, but I would like a good reception even without that. Anything below 10 meters should be good, that's what my old Garmin etrex was like.

edit: Alternatively, can one use bluetooth GPS units with some phones?

edit2: Yes, apparently gpsd runs on Maemo. On Android you can install Debian anyways so there too. Sweet!


Posted by HannesHH on 28 November 2009 in English (English).

If some place is already mapped, please do not blindly "improve" it by re-adjusting everything to Yahoo imagery. It might be that someone spent a lot of time re-, re- and rewalking those paths and that the images are not aligned correctly.


edit: Is there someone from Yahoo in the community and easily reachable? At Yahoo's maps page there is a feedback link but it requires an Yahoo account (morons...).

Read the blog:
Or go directly to the maps:
Kabul, Afghanistan:
Baghdad, Iraq:

You might also be interested in (using geotagged photos to "create shapes")

Node gluttony for areas

Posted by HannesHH on 21 September 2008 in English (English). Last updated on 29 March 2012.

Please be aware that this is a quite heatedly discussed subject. One side says "yes, this is how to do it", the other "no, that is just wrong". So please decide for yourself what "side" to choose (and of course decide case by case).

Many people map areas using new nodes. This might be the (seemingly) most easy way but it has several disadvantages when the area in fact is "attached" to nearby streets in the real world:

a) When moving the streetnodes around, the area has to be adjusted by hand. That's unnecessary extra work.
b) It's gluttony, the right nodes already exist.
c) Due to not connecting street and area there might un-intended gaps when rendered.

How to map:
Simply start your area and click on the already existing nodes, it's like magic!

How to edit:
If you have an area like above there is no "free" side of it to click on, if you want to select it. No idea about Potlatch here. In JOSM press and hold middleclick on any side, then press and hold CTRL, leftclick on the desired way in the popup.

How to fix:
Enter The Great Merge Tool (M in JOSM). It seems to be rather dick-headed in its behaviour though... If it merges to the wrong node just undo, zoom in a lot and try to place both points just above each other. Maybe there is a way to tell it how to merge, but shouting at it is quite satisfying.

And now shout at me!

Die wohl häufigste "Beschwerde" in Kommentaren nach Artikeln über OpenStreetMap in den deutschen Medien der letzten Zeit ist wohl "da sind überall weiße Flecken".

Ich habe mal ein bisschen mit herumgespielt und festgestellt, dass teilweise auch dörfliche Gegenden wirklich super Bilder haben. Also habe ich einfach mal 2 Dörfer von diesen Bildern gemappt: Straßen als "highway=road" & "source=yahoo aerial images" (o.ä.), Sportplätze, den Umriss des Dorfes als "landuse=residential". Für ein kleines Dorf ist es eine Sache von 5-10 Minuten. Sicher, Straßenname fehlen dann noch, aber da könnten zB die Bewohner des Ortes mit OpenStreetBug sehr einfach nachhelfen (nicht vergleichbar mit der Komplexität von den Mapeditoren).

Also, huschhusch, macht die Flecken streifig! Es bringt unglaublichen Spaß. :-)

PS: habe ich mitgemacht und es hat mich ziemlich motiviert (die Möglichkeit die "Reise zu gewinnen" nicht berücksichtigt). Wäre das vielleicht auch etwas für ein Deutschland-Projekt? Also Spenden&Mappen in Gemeinschaft, kein möglicher Preis (außer jemand will das übernehmen)?

There is a nice article about OSM at
"We have written about the OpenStreetMap (OSM) project many times, but we have yet to explain how to get started with it as a contributor. Since it is the vacation high season in the Northern Hemisphere and many more people will be hitting the maps, this is the perfect time."

This is a great introduction for newbies. Go read it and then send it to all your friends (actually, yes, why not):

JOSM's YWMS plugin on Linux if FF3 is in your repositories

Posted by HannesHH on 15 July 2008 in English (English). Last updated on 8 February 2009.

JOSM's YWMS plugin currently only works in Firefox 2. So if you for example use Debian Lenny and it's got Firefox 3 in the repositories you are screwed. This is how I fixed it.

Note: This might create a mess if you have Firefox 3 installed and use it. I switched to Opera so I don't care. :)

Download the latest
Put it somewhere (for example: ~/projects/openstreetmap/firefox
tar xfvz firefox-

Now start JOSM, go to the YWMS plugin's settings and set the path to
Click the create button for the profile and follow the instructions.

The last few months spent a lot of time into mapping the western parts of Hamburg, Germany by bike and foot. Now the map is in a state where most streets and ways are present.

And since I feel like a proud daddy for this region I want to "maintain" it. I want to be able to track any changes, I want to be able to see who did what when. I want to be able to discuss, compare, revert.

Searching through the wiki (painful these days, couldn't someone make a browsable static copy of the pages it until the performance issues are solved? I'd volunteer to host it.) I could not find any way to do this. But maybe there is?

Location: 22587, Germany