Re: [Talk-in] Mapping the Indian Railway network using high resolution Landsat imagery

2010-05-02 Thread Arun Ganesh
A more interesting visualization of the IR network with the age of the edits
http://www.flickr.com/photos/arunganesh/4570968389/

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[Talk-in] Mapping the Indian Railway network using high resolution Landsat imagery

2010-04-30 Thread Arun Ganesh
If nobody's noticed already, i've been adding a significant amount of
railway lines in Southern India. Infact the entire railway network of Tamil
Nadu and Kerala are in. It should start rendering in low zoom in a week i
guess. You can check out an extract of the railway network processed with
qgis 
herehttp://en.wikipedia.org/wiki/File:Tamil_Nadu_Urban_Areas_and_Railway_Connectivity_Map_(openstreetmap).png
.

How was the tracing done? Well, i seem to have uncovered a sharpened version
of landsat imagery with which it is possible to identify details like
railroads and major highways, especially if its running through fields/rural
areas. In JOSM, goto the WMS plugin preferences and add the following url to
access the sharpened global mosaic landsat tiles:

http://onearth.jpl.nasa.gov/wms.cgi?SERVICE=WMSVERSION=1.1.1REQUEST=GetMapLAYERS=global_mosaicSTYLES=visual_lowFORMAT=image/jpeg;

On important thing to note is that the landsat wms layer can be off by upto
100metres, so you might need to reposition the layer using gps tracks first.
The resolution of these tiles are far superior to the default landsat
imagery and you can mark highways, railroads, railway stations, airports,
villages/built up areas, farmlands and waterbodies. I wonder why its not
listed in the WMS plugin by default.

If we can manage to put in the skeletal network of the railways in OSM, it
will be easy to get members from IRFCA involved in adding more details.
There are many of them who are so well versed with the railway network that
they would be able to add station codes and station locations just by
looking at the geometry of the railway lines. And later possibly even set up
a dedicated Indian Railway OSM tile server, like whats available for the UK.
I'm sure a lot of travel sites would be interested in something like that.

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Re: [Talk-in] Mapping the Indian Railway network using high resolution Landsat imagery

2010-04-30 Thread Srikanth Lakshmanan
On Fri, Apr 30, 2010 at 4:07 PM, Kenneth Gonsalves law...@au-kbc.orgwrote:


 well, I travelled from coimbatore-pollachi-dindigul-madurai, the tracks
 were
 there - but no trains. broadgauge conversion is going on. How do we map
 this?


I remember seeing some under-construction attribute for fly overs / roads. I
think this can be used.

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Re: [Talk-in] Mapping the Indian Railway network using high resolution Landsat imagery

2010-04-30 Thread Arun Ganesh
On Fri, Apr 30, 2010 at 4:20 PM, Srikanth Lakshmanan srik@gmail.comwrote:



 On Fri, Apr 30, 2010 at 4:07 PM, Kenneth Gonsalves law...@au-kbc.orgwrote:


 well, I travelled from coimbatore-pollachi-dindigul-madurai, the tracks
 were
 there - but no trains. broadgauge conversion is going on. How do we map
 this?


 I remember seeing some under-construction attribute for fly overs / roads.
 I think this can be used.

 i guess a railway=construction + construction=rail should work

Btw you can check out the indian railway network extract here
http://www.flickr.com/photos/arunganesh/4566060392/
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