Re: [Talk-in] Indian Slum Mapping

[PlaneMad]

On Thu, Mar 18, 2010 at 11:31 AM, Kenneth Gonsalves wrote:

> let me rephrase that: since Mumbai data is skewed, when mapping any area
> the
> first job is to realign the streets. Naming is more or less ok, but the
> streets
> are out of place. The Yahoo satellite imagery may be relied on as on
> testing
> with GPS in various parts of Mumbai, it is accurate. However due to heavy
> tree
> cover in many parts, it is difficult to trace without GPS tracks.
> --
>
>

>From my experience fixing Mumbai, i have come to realize that its pretty
much impossible to realign the streets in parts without confusing yourself.
I had started deleting unnamed AND ways to make the task easier, but that
didnt help too much as you lose the reference street geometry to match with
the yahoo imagery.

I feel the best way to fix the map is to remove all the AND paths
completely, start tracing the roads and name them by using an old extract of
the original AND import as reference. Good idea?
-- 
http://j.mp/ArunGanesh
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Re: [Talk-in] Indian Slum Mapping

[निशांत / Nishant]

On Wed, Mar 17, 2010 at 10:59 PM, PlaneMad  wrote:
> Quite interesting, while trying to clean up the mumbai map, i was wondering
> what to do with all those slum areas which form a huge part of the city. Its
> quite easy to identify slums areas on yahoo imagery as the structures have
> small roofs. And if ISRO is just planning to map slum land areas and not the
> insides, then we can do a much faster job than the govt, sitting at home and
> collaborating together on a particular city.

If ISRO just maps the outline of slum area, it will look like patches
on the map and all that government would be able to get is how much
sq. kms are covered. Then the estimate of number of people living in
slum areas by multiplying it with population density will arrive at a
figure that would most probably be far from the reality. And the
number of houses built for slum dwellers will fall short in numbers
and new slums will start taking shape.

IMHO, this needs much more ground work for surveying these areas than
simply drawing them on the map while sitting at home. But yes, the
maps that we prepare can serve as a good base for survey agencies.

We need to identify what all amenities or POIs need to be mapped in
addition to boundaries, lanes, public water taps/handpumps etc. that
will be helpful to the government in executing this project.

regards,
Nishant
-- 
How about some patent on "(a+b)2 = a2+2ab+b2". Choose free software!
http://www.nishants.net

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Re: [Talk-in] Indian Slum Mapping

[Kenneth Gonsalves]

On Thursday 18 Mar 2010 8:57:45 am Schuyler Erle wrote:
> > do not forget that nearly all Mumbai data is b0rked - apart from a few
> > places  where some of us have corrected it. It needs to be corrected
> > first.
> 
> I wouldn't say "first" because it's such a big job to do all at once
> that it'll never happen. I'd say instead "at the same time, because it
> needs to be corrected eventually." :)
> 

let me rephrase that: since Mumbai data is skewed, when mapping any area the 
first job is to realign the streets. Naming is more or less ok, but the streets 
are out of place. The Yahoo satellite imagery may be relied on as on testing 
with GPS in various parts of Mumbai, it is accurate. However due to heavy tree 
cover in many parts, it is difficult to trace without GPS tracks.
-- 
regards
Kenneth Gonsalves
Senior Associate
NRC-FOSS
http://certificate.nrcfoss.au-kbc.org.in

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Re: [Talk-in] Indian Slum Mapping

[Schuyler Erle]

* On 17-Mar-2010 at 10:10PM EDT, Kenneth Gonsalves said:
> On Wednesday 17 Mar 2010 10:59:27 pm PlaneMad wrote:
> > I suggest all of us get together and map all the slum area in mumbai that
> >  we can identify through yahoo imagery
> 
> do not forget that nearly all Mumbai data is b0rked - apart from a few places 
> where some of us have corrected it. It needs to be corrected first.

I wouldn't say "first" because it's such a big job to do all at once
that it'll never happen. I'd say instead "at the same time, because it
needs to be corrected eventually." :)

SDE

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Re: [Talk-in] Indian Slum Mapping

[Kenneth Gonsalves]

On Wednesday 17 Mar 2010 10:59:27 pm PlaneMad wrote:
> I suggest all of us get together and map all the slum area in mumbai that
>  we can identify through yahoo imagery
> 

do not forget that nearly all Mumbai data is b0rked - apart from a few places 
where some of us have corrected it. It needs to be corrected first.
-- 
regards
Kenneth Gonsalves
Senior Associate
NRC-FOSS
http://certificate.nrcfoss.au-kbc.org.in

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Re: [Talk-in] Indian Slum Mapping

[PlaneMad]

Quite interesting, while trying to clean up the mumbai map, i was wondering
what to do with all those slum areas which form a huge part of the city. Its
quite easy to identify slums areas on yahoo imagery as the structures
have small
roofs . And
if ISRO is just planning to map slum land areas and not the insides, then we
can do a much faster job than the govt, sitting at home and collaborating
together on a particular city.

This is a very good opportunity to showcase the crowdsourcing abilities of
osm for social causes to the Indian public as well as the govt. I'll have to
apologize for working silently in the background with OSM data, on which
i'll write about soon. But i have experienced first hand the absolutely HUGE
void of geographic data in the country that so many different people from
different areas need, and how OSM could help, but nobody knows about its
existence!

I suggest all of us get together and map all the slum area in mumbai that we
can identify through yahoo imagery. I dont think it would take more than a
few days if we all work together. If we have that data in, we could probably
pull it out to make some very interesting infographic like comparing slums
space to open space/parks and spread it virally through the internet to
raise awareness about OSM, and possibly also to the govt. Anyone open to the
idea?

-arun


On Wed, Mar 17, 2010 at 2:28 PM, Mikel Maron  wrote:

> Anyone know more about this?
> http://timesofindia.indiatimes.com/india/For-accurate-data-govt-plans-to-map-slums/articleshow/5574451.cms
>
> Sounds like they are only planning to use remote sensing techniques to
> identify slum areas. On the ground OSM work would be ideal complement. And
> that imagery ... imagine what else we could use it for!
>
> Any links here welcome, we have a long term view to look at Map Kibera like
> projects in India.
>
> -Mikel
>
> == Mikel Maron ==
> +254(0)724899738 @mikel s:mikelmaron
> http://mapkibera.org/
> http://wiki.openstreetmap.org/index.php/Haiti
>
>
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[Talk-in] Indian Slum Mapping

[Mikel Maron]

Anyone know more about this? 
http://timesofindia.indiatimes.com/india/For-accurate-data-govt-plans-to-map-slums/articleshow/5574451.cms

 
Sounds like they are only planning to use remote sensing techniques to identify 
slum areas. On the ground OSM work would be ideal complement. And that imagery 
... imagine what else we could use it for!

Any links here welcome, we have a long term view to look at Map Kibera like 
projects in India.

-Mikel

== Mikel Maron ==
+254(0)724899738 @mikel s:mikelmaron
http://mapkibera.org/
http://wiki.openstreetmap.org/index.php/Haiti
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