Best practice: offline mapping?

Posted by Chaos99 on 26 October 2009 in English (English).

I'm planing to do a longer holiday abroad and will take my GPS and
openstreetmap with me.

I will probably find a lot of new things to map, but I won't have an
internet connection at hand.
Does anybody have some advice on how to keep track of things to add?

I normally add points with notes directly on my GPS (eTrex), but that's
very time consuming, I can't do it while driving
and I only can add very short notes. I usually get frustrated with the
on-screen keyboard within 1 or 2 days and subsequently stop taking

Only mark numbered points would be faster and easier, but I would have to
keep notes on another medium (paper notebook, netbook).
Merging these two data heaps will be time consuming afterwards.

As I have a netbook with me which could run JOSM, I could edit live or at
least at the end of each day. This would keep the frustration level low.
But I don't know if I can savely merge the data back into the osm data on ther servers.

Does anybody have some advice? Or some info on how you map on holidays?



Comment from wallclimber21 on 26 October 2009 at 14:30

I never write anything down, but just take tons of pictures that are either geotagged by the device itself (in case I take them with the standard app of the iPhone) or geotagged by using the timestamp and correlating it with the recorded track (when I take them with a digital camera and use a garmin GPS).

When I'm driving, I obviously can't write anything down or take pictures, so I use the iPhone voice recorder app to make notes.

Geotagging those currently doesn't work very well, so I do it like this:
"Intersection of Market street and route XYZ, left side, Texaco gas station".

Ideally, I want an iPhone app that does 3 things:
- record GPS track
- take pictures at full resolution that are geotagged
- record voice notes that are also geotagged

I'm currently writing one that does exactly that.

Comment from Chaos99 on 26 October 2009 at 14:48

As I'm on Holiday, I will probably take thousands of pictures anyway. But mixing osm reference pictures with holiday photos is not a good idea. (And it will drain my camera battery quite fast.) I have to consider bringing along another small camera to do that kind of work.

I unfortunatly don't own neither a smartphone nor a PDA. So doing all the tracking, voice recording and image taking with one small device is out of option. Actually the only device which lasts for days on batterie is my GPS device. My netbook will last for some hours, but is to complicated to use while driving. I don't know if I can convince my girlfriend to take the notes/photos.

Comment from amm on 26 October 2009 at 21:37

Do you have any kind of phone? It is often not necessary to have a smartphone to do this, as many simpler phones are capable of doing that too. If it runs mobile java there is a good chance there will be an app that can take photos and record voice and if you have a builtin gps or a bluetooth gps receiver can geotag them for you. If your worry though is battery life, then that is indeed a different matter as typically it is difficult to get more than a days worth recording out of a phone, though you could probably recharge in your car.

Getting back to your original question, I think if you can do offline mapping with JOSM over an extended period of time depends quite a bit on where you are going. If you go to an area that doesn't have much OSM activity, chances are probably fairly high that you won't get any conflicts and can just upload it at the end. Also since API 0.6, you should no longer be able to "destroy" changes that were done in the meantime, as with the versioning of the data, JOSM would detect when there are conflicts and hopefully provide you with the option to resolve them. How well that works I can't say though and personally I would rather recomend to just take photo notes. At least for me that has in the past worked fairly well.

Comment from Longbow4u on 26 October 2009 at 21:46

I usually only record the GPX-Track and write notes in a paper notebook. I draw a sketch of the road network and add numbers for the streetnames. At the side I keep a legend of the names and numbers. I apply a date to the sketch so I know which day I recorded which track. I add further details like position of housenumbers. In the evenings I edit in JOSM and upload to the database. It takes time, but I can split the task as needed. E.g. editing streetnames and road network one day, adding Points of interest, shops and housenumbers the other day. Obviously I do not write while driving. I turn the car to the side as needed to take notes. No fiddling with inadequate screens. Easy editing. Lot of details. :-)

Comment from Ale_Zena_IT on 26 October 2009 at 21:58

I use a little, simple, cheap 20€ MP3 player with Voice Rec feature.
Happy holiday

Comment from datalogg on 26 October 2009 at 23:06

I have an open source app on my phone called MobileTrailExplorer that saves my bluetooth GPS mouse's data stream. I can make a waypoint by hitting #, and edit the name using the phone's native textbox widget. Having become proficient with entering text on the thing (SMSes mostly), this is actually fairly doable.

A bigger problem is putting the damn GPS away and actually enjoying the holiday...;-)

Comment from Chaos99 on 27 October 2009 at 06:50

@Ale_Zena_IT could you tell my the brand of your mp3 player? I've searched for one on this purpose, but found that usable voice recording was a feature which apeared at 50+ Euros first.

@amm I have a phone, yes. But all it can do (Ok, it can do texts too). Definetly no java, no camera, no memory card, no bluetooth, no voice recording. But it's good to hear that JOSM handles conflicts gracefully by now.

@datalogg see my phones details above. But your last point is actually the biggest problem. Especially as I am not traveling alone. The enjoyment of holiday may be enforced if I fiddle too much with OSM stuff.

Comment from Boudewijn on 28 October 2009 at 21:07

I use wallclimber21's solution: loads of pictures :-)

Indeed I got quite a few intersections intersecting our holiday pictures, but they're not too hard to sort out again.

In my opinion, using just one camera with extra batteries (and memory) is favourable over using a seperate lower quality camera for tagging. I take pictures in highest quality in as much wide angle as possible, as to get as much details in a single shot as possible.

Afterwards aligning them with the track using a photo of the GPS-tracking device and finally using them for making the map. JOSM can show your geotagged pictures, as can potlach and I guess merkaartor does as well (can't remember at the moment).

Potlach needs you to upload the photo's to I only did so for a tryout with a couple of them. You can see them by editing this location in Potlach, and turn on photo's (bottom left icon, next to options):

They're not all as usefull, since indeed, I also took pictures of the surroundings. Besides that, there were hardly any roadsigns to be found :-)

Good luck and have a nice holiday!

Comment from Niels Elgaard Larsen on 17 June 2010 at 13:03

I usually do not make too many notes in Denmark since every address is already imported, making it possible to figure out roadnames in most cases.

A voice recording utility would be nice. It does not necessarily have to be geotagged. Timestamps would do. Just a application that would make a new mp3/ogg file every time you pressed "record". They it would be trivial to match sound files with streets using file time-stamps.

I have an old mp3 player, that can record. I will give it a try.

Comment from Chaos99 on 17 June 2010 at 13:59

Hi, thanks for commenting on that half year old post. (No, that's not sarcastic, I'm really grateful for any feedback.)

I looked for really cheap (<= 20Euro) voice recording tools, but found none. I also looked for mp3 players with this functionality in the same price range and found none. For a single purpose I would only use for OSM I wasn't willing to spend more money.

Now my wife bought an iPod mini, which does have recording capabilitys. I may use this if I go mapping again. What's now missing is free time and my motorbike, which is broken.

It's not like 'which cool tech tools can give me best data' anymore. (I was experimenting with head mounted cameras and stuff). But more about 'how to get usefull data for osm while not actualy being mapping'. That's while being on holiday or visiting friends or whatever. I (sadly) don't have the time for exclusive osm tours anymore. And strapping a helmet camera on or stopping at every street sign isn't an option while on holiday.

So all I have for now is GPS traces, (holiday-)pictures and my memory to donate to osm.

Comment from Chaos99 on 17 June 2010 at 14:06

There is obviously something missing in the last comment. That's what's missing behind the lonely "(":

less than 20 Euro) voice recorder or a mp3 player with recording functionality but found none. I wasn't willing to spend more money on such a single-purpose tool I would only (possibly briefly) use just for osm.

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