<div dir="ltr">(Two threads got started for this topic, so we've copying the other thread over here. I've also added a little reply to Sid's new post at the end.)<br><br>---------- Forwarded message ----------<br>
From: <b class="gmail_sendername">Pat Tressel</b> <span dir="ltr"><<a href="mailto:ptressel@myuw.net">ptressel@myuw.net</a>></span><br>Date: Fri, Aug 1, 2014 at 11:34 PM<br>Subject: Re: [OSGeo-Discuss] Inquiry: Help please!<br>
To: "S.A. Mouti" <<a href="mailto:moutia@outlook.com">moutia@outlook.com</a>><br>Cc: OSGeo Discussions <<a href="mailto:discuss@lists.osgeo.org">discuss@lists.osgeo.org</a>><br><br>Hi, Sid!<div><div class="h5">
<div class="gmail_extra"><br><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div style="word-wrap:break-word">
<div><div style="color:rgb(0,0,0)"><p class="MsoNormal" style="margin:0in 0in 0.0001pt"><span style="font-size:13px"><span style="color:rgb(0,0,0);background-color:white">I would like to develop an algorithm that uses remote geographic sensing data </span>to
automatically identify, highlight, and measure rooftops and
buildings surfaces and contours using Geospatial data. My preference is
to overlay the results on one of the existing map providers such as
Google Earth/maps or Bing . </span></p>
</div><div style="color:rgb(0,0,0)"><p class="MsoNormal" style="margin:0in 0in 0.0001pt"><font style="font-size:13px"><font color="black"> </font></font></p></div><div style="color:rgb(0,0,0)">
<p class="MsoNormal" style="margin:0in 0in 0.0001pt"><font style="font-size:13px"> My aim is to get the following outputs from the proposed model:</font></p></div><ul style="color:rgb(0,0,0);margin-bottom:0in" type="disc">
<li class="MsoNormal" style="margin:0in 0in 0.0001pt"><font style="font-size:13px"><font color="black">Accurately highlighted and identified rooftops on Google maps (using geo sensing data, elevation? and </font></font></li>
<li class="MsoNormal" style="margin:0in 0in 0.0001pt"><font style="font-size:13px"><font color="black">Property Address or GPS coordinate.</font></font></li><li class="MsoNormal" style="margin:0in 0in 0.0001pt">
<font style="font-size:13px"><font color="black">Surface and square
footage available for solar power generation including the position of
the property(N-S or E-W). At the exact surface of the south facing
portion of the roof.</font></font></li><li class="MsoNormal" style="margin:0in 0in 0.0001pt"><font style="font-size:13px"><font color="black">Integrate sun tool in google maps to calculate shading for each building.</font></font></li>
<li class="MsoNormal" style="margin:0in 0in 0.0001pt">
<font style="font-size:13px" color="black">Total surface/square footage of the roof. </font></li></ul><div style="color:rgb(0,0,0)"><font style="font-size:13px"><br></font></div><div><div style="color:rgb(0,0,0)"><font style="font-size:13px">I would appreciate your guidance on the following:</font></div>
<ul><li style="color:rgb(0,0,0)"><span style="font-size:13px">Any individual developers or companies active in this area who would be willing to undertake this challenge</span></li><li style="color:rgb(0,0,0)"><span style="font-size:13px"><font style="color:rgb(0,0,0)">View on technical do-ability of the </font>project…</span></li>
<li><span style="font-size:13px">What free geospatial data is
available/needed to build the model and who the providers are? (I
understand that US cleared higher resolution imagery for domestic )</span></li><li style="color:rgb(0,0,0)">
<font style="font-size:13px">An idea about the overall cost for such a model.</font></li></ul></div><div style="color:rgb(0,0,0)"><span style="font-size:13px">Best regards,</span></div><div style="color:rgb(0,0,0)"><span style="font-size:13px"><br>
</span></div><div style="color:rgb(0,0,0)"><span style="font-size:13px">Sid <br></span></div></div></div></blockquote></div><br></div></div></div><div class="gmail_extra">Just want to mention two things:<br><br></div><div class="gmail_extra">
1) Building outlines are available for some locations in both commercial
maps (Google and Bing, for instance). In OpenStreetMap, if buildings
have not been mapped for a specific area you're interested in, you might
be able to get local mappers to do it. (Of course, the building
outlines obtained that way may not be accurate. Many times, the
building outline is simplified from the actual building as it's only
needed to indicate, "there is / was a building here", e.g. for rescue
workers looking for survivors after a natural disaster.)<br>
<br></div><div class="gmail_extra">2) If you use satellite imagery (or
possibly low-elevation imagery if you have accurate info on the camera
path and orientation), then the shadows cast by buildings can be used to
estimate their height. A very brief web search turns up a fair number
of papers on this -- just one example, with references to earlier work
that may be more relevant:<br>
<br><a href="http://www.asprs.org/a/publications/pers/98journal/january/1998_jan_35-44.pdf" target="_blank">http://www.asprs.org/a/publications/pers/98journal/january/1998_jan_35-44.pdf</a><span class=""><font color="#888888"><br>
<br></font></span></div><span class=""><font color="#888888"><div class="gmail_extra">-- Pat</div></font></span><br><div class="gmail_extra"><br><div class="gmail_quote">On Sat, Aug 2, 2014 at 10:55 AM, S.A. Mouti <span dir="ltr"><<a href="mailto:moutia@outlook.com" target="_blank">moutia@outlook.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div style="word-wrap:break-word;color:rgb(0,0,0);font-size:14px;font-family:Calibri,sans-serif"><div>
<div>Thank you Barend and I look forward to hearing Sander’s views.</div><div><br></div><div>I think another way I imagine this would be possible is through using high resolution elevation data (1 meter or better). In this case, a scanning algorithm to identify buildings contours and rooftop would do the trick quite accurately. The rest is integrating the Google sun tool and matching the elevation data to any map provider to get addresses… I know it’s doable. I just don’t have the technical capabilities to do it. Again, this is my non-expert opinion and there might be some technical or other limitations that I am not aware of. Hence my reach out.</div>
<div><br></div><div>Kindest regards,</div><div>Sid<br></div></div></div></blockquote><div><br></div><div>Is there public / open-source elevation data with that accuracy, or is that commercial?<br><br></div><div>Here's a nice summary of public elevation datasets:<br>
<a href="http://vterrain.org/Elevation/global.html">http://vterrain.org/Elevation/global.html</a><br></div><div>Some specific public datasets and tiles:<br><a href="http://asterweb.jpl.nasa.gov/gdem.asp">http://asterweb.jpl.nasa.gov/gdem.asp</a><br>
<a href="http://www.cgiar-csi.org/data/srtm-90m-digital-elevation-database-v4-1">http://www.cgiar-csi.org/data/srtm-90m-digital-elevation-database-v4-1</a><br><a href="http://topotools.cr.usgs.gov/gmted_viewer/">http://topotools.cr.usgs.gov/gmted_viewer/</a><br>
<a href="http://www.ngdc.noaa.gov/mgg/topo/gltiles.html">http://www.ngdc.noaa.gov/mgg/topo/gltiles.html</a><br><a href="http://glcf.umd.edu/data/glsdem/">http://glcf.umd.edu/data/glsdem/</a><br><br></div><div>-- Pat<br></div>
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