[OSM-talk] Mapping Klong Toey Slums

Pierre Béland pierzenh at yahoo.fr
Thu Jul 14 15:15:03 UTC 2016

A funny and cheap alternative method to trace the narrow alleys and have good coordinates of POI's in the alleys : A small GPS tracker attached to a Balloon. You probably just have to assure to keep the balloon over the roofs both to have a good gps signal and to protect the balloon.

You coul try to have a small gps attached to a balloon with a good rope and protected in a plastic bottle. It would then be possible to walk in the alleys, take notes, use Field Paper drawings+notes and take pictures (mappillary or other) + time. Coming back you can compare the various notes / sketch / pictures and the traces using time. 

You just need to be carefull to synchronize time on GPS and other units. There are softwares to correct images coordinates with gps traces.
See http://www.aprs.org/balloons.html

      De : Pierre Béland <pierzenh at yahoo.fr>
 À : "talk at openstreetmap.org" <talk at openstreetmap.org> 
Cc : Klaikong Vaidhayakarn <klaikong at gmail.com>; Garavig Tanaksaranond <Garavig.T at chula.ac.th>; Mishari Muqbil <mishari at mishari.net>
 Envoyé le : jeudi 14 juillet 2016 9h52
 Objet : Re: [OSM-talk] Mapping Klong Toey Slums
Hi Mishari,
This is efffectively a good challenge to map such area.  With the dense housing, remote mappers cannot interpret the imagery and spot either klones or paths.  From local knowledge, 

The first step would be to trace as much info as possible from the imagery :- big buildins- parks- klones and paths (with local knowledge, you can probably interpret the images and trace)

For the second step, as you suggested, various methods could be used. This is also and interesting challenge to try various ones and compare. With enough details added to the map, it would be possible I think to use FieldPapers and add POI's as restaurants or other features.

Drone imagery is also interesting if you can have authorization to fly in the area. We used drone imagery in north of Haiti to trace in dense areas and we could see easily paths around the houses. But the area was not as dense as yours.  

      De : Mishari Muqbil <mishari at mishari.net>
 À : talk at openstreetmap.org 
Cc : Klaikong Vaidhayakarn <klaikong at gmail.com>; Garavig Tanaksaranond <Garavig.T at chula.ac.th>
 Envoyé le : jeudi 14 juillet 2016 6h58
 Objet : [OSM-talk] Mapping Klong Toey Slums
I just wanted to feedback from the community for our effort to map the slums in Klong Toey, Bangkok. The size of the area is about 1km x 2 km around here and I have captured a sequence on Mapillay here. There are several challenges here including access to internet and English literacy, so I have come up with the following rough plan.
1. Put out a call for volunteers, work with NGOs in the area to find local kids who are interested in putting their community on the map.
2. Train the kids in using ID editor. I think I will limit them to doing specific things i.e. walkways, houses, trees, restaurant, convenience stores with individual kids limited to 2-3 features to avoid confusion then as they get the hang of it, increase their repertoire.
3. Take over a local internet cafe for a day for training and mapping purpose.
Now I'm not sure about the rest of the process, you can see from Mapillary that due to the somewhat dense nature of the community, GPS is inaccurate and neither Bing nor Mapbox has enough of a resolution to be meaningful. So I have several (possibly overlapping) ideas.
a) hire or borrow a drone to take aerial imagery and upload to openaerialmap and use that as a basemap but I'm not sure how possible it will be to see through the roofs.
b) get a team of surveyor students from Prof. Garavig to map out the paths in the community (it's pretty big so I'm not sure how tine consuming it is) then have the community kids fill in the blank.
c) use walking papers and have the kids go out, sketching what they see from the rooftop but I feel this may be prone to errors.
Does anyone have any experience or tips they can share on how we can achieve this?
Best regards

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