My 2 partners and I have started a free online travel map for visitors on the Island of Bali in Indonesia ( https://zoombali.com ). We are using MapBox which is powered by OSM data.
By comparing the streets in Bali from Google Maps and from our map (OSM) I realized that a lot of streets are missing and Google Maps looks more up-to-date.
After an investigation, I noticed that in Bali the Satellite Images from Google Maps are dated around March 2015 and May 2015 (only Google Earth give such information when you zoom-in). Then I found the following website http://mvexel.dev.openstreetmap.org/bing/ who display capture date for Bing Aerial Imagery. In average Bing Aerial Imagery have been captured around 2011-2012 in Bali. Since then many new roads and residential area has been built in Bali, Indonesia.
I would like to know if there’s a way for me and my partners to add the new roads in Bali ?
Is there another aerial imagery source ? Should we contact Yahoo or Bing for asking if an Aerial Imagery upgrade is possible for Bali ? Or should we go outside to collect GPS tracks for then add it in OSM ?
The real answer is that you have to convince people in Bali to map the roads themselves using GPS. You are going to need people on the ground to get the meta data, unless there is open use government mapping.
OSM doesn’t have permission for all the Bing imagery, only that taken from directly overhead, and that will have been a carefully chosen commercial compromise by Bing. It may even be that they have basically said that Google has much better imagery of that type, so a better use of their investment in it is to use it to get OSM maps that they can use as one of their map alternatives.
Unfortunately, it seems that the level of amateur mapping in a country strongly correlates with the wealth of the country, rather than with the mobile phone ownership rates, even though the only direct costs are generally already covered if you have a smart phone.
A 3-4 years old imagery is not such bad - in some areas of Germany, it’s older.
When comparing with Google Maps, take care: many roads found there may not even exist, as people with little experience with imagery draw them from Google imagery - mistaking the footprint of a tractor for a road.
Another problem with Bali is tree cover. Several roads in the country side are hardly visible due to the big trees of forests or plantations. And it is often important to go to the place and take a closer look: a narrow road with concrete lanes might be too challenging for an average tourist ( http://www.panoramio.com/photo/84085819
), some bridges can be used by motorbikes but not cars ( http://www.panoramio.com/photo/84102847
), and local motorbike drivers use small paths you’d normally not consider, and some roads are in a devastated state, and …
So it is really worth taking data on ground, not from imagery only.
M. Hiller I am a newby with OSM mapping but with your examples I do understand why it’s really worth taking data on ground, not from imagery only. Today for the first time, I downloaded the application OSMAnd on my Android smartphone and found a new road (not displayed on the map of OSMAnd application) and I started to record a GPX file while I was driving with my motorbike on the new road. Then I get back to my house with my WiFi (to avoid paying data fee) and uploaded the trace on OSM (always with the app OSMAnd).
I’ve been reading hours on wiki different info about OSM but I would like to know if you could guide me towards specific info about editing OSM map. For instance, I’m wondering when my new trace will be displayed. Then I try to understand how to specified the type of road (should I download JOSN for that ?)… so many questions… it’s overwhelm for a beginner.
Like we say in Bali “Sedikit Sedikit” One step at the time.
Uploading the gps trace is not enough. You’ll need an editor like JOSM. Import that GPS track in JOSM, download the data of the relevant area, and then trace your new road from it, connect it with existing roads, add the relevant tags, and upload the data. A little time later, the road will be displayed on the map (you may need to clear your browser cache to get a fresh map, or explicitly request re-rendering of the area).
Don’t get confused if your GPS data are a few meters away from aerial imagery - there is often an offset, mainly in mountain areas or areas with hardly GPS data available; in case of doubt, prefer the GPS data.
There are some tutorials available on JOSM. And yes, it will take some time to get used to it. Don’t get discouraged. It is feasable.
GPS data taken at different times will also show discrepancies of a few metres. As someone has pointed out that many roads, in Bali, are obscured by trees, GPS data can have quite large errors, as you need to be able to see satellites in multiple directions at relatively low elevations to be able to get a good position solution. (You don’t want too low elevations, but I would guess you ones at about 30 to 45 degrees above the horizon.) If you don’t have a perfect view of the sky over the whole length of the track, you may find parts of the track that are over 20m out compared with other parts on the same track.
As such, you need to take into account all sources, including existing OSM mapping, and some common sense about the real life straightness of features.
