Comments on: How high? http://highearthorbit.com/how-high/ Transmitting ideas, observations, and images from 42,000 km. Sat, 22 Nov 2008 06:54:14 +0000 http://wordpress.org/?v=2.6 By: Versicherungen vergleichen http://highearthorbit.com/how-high/#comment-200069 Versicherungen vergleichen Fri, 29 Aug 2008 23:45:50 +0000 http://highearthorbit.com/how-high/#comment-200069 Thanks, you wrote wonderfull. Thanks, you wrote wonderfull.

]]> By: Jonathan Stott http://highearthorbit.com/how-high/#comment-94952 Jonathan Stott Thu, 12 Jul 2007 22:58:46 +0000 http://highearthorbit.com/how-high/#comment-94952 Hi, Thanks for the EarthTools.org mention! I notice that Leszek mentions that buildings skew the SRTM data - this is an obvious artifact of the data being acquired using radar from a space shuttle. A good example is in London: http://www.earthtools.org/map/51.50468231156/-0.013475418090820312/14/0/Contour/ - a small mountain exists (about 30m high) around Canary Wharf and the Dome on the other side of the river (near North Greenwich) is picked out nicely by the 10m contour line! Sadly no better free data exists for the UK. Better data does exist for America (and Canada), but it will take me a while to process it and integrate it with the SRTM data. Hi, Thanks for the EarthTools.org mention! I notice that Leszek mentions that buildings skew the SRTM data - this is an obvious artifact of the data being acquired using radar from a space shuttle. A good example is in London: http://www.earthtools.org/map/51.50468231156/-0.013475418090820312/14/0/Contour/ - a small mountain exists (about 30m high) around Canary Wharf and the Dome on the other side of the river (near North Greenwich) is picked out nicely by the 10m contour line!

Sadly no better free data exists for the UK. Better data does exist for America (and Canada), but it will take me a while to process it and integrate it with the SRTM data.

]]> By: Leszek Pawlowicz http://highearthorbit.com/how-high/#comment-88610 Leszek Pawlowicz Wed, 13 Jun 2007 00:59:39 +0000 http://highearthorbit.com/how-high/#comment-88610 My experience with creating sea level rise simulations: http://freegeotools.blogspot.com/2007/04/sea-level-rise-storm-surge-and-flooding.html http://freegeotools.blogspot.com/2007/05/high-resolution-sea-level-rise-flooding.html showed me that the building height data is not "washed out" in SRTM. Using SRTM data for a flooding simulation of Manhattan results in less flooding than using standard NED data that conforms to the ground, because the building heights skew the SRTM data. Those results are even more pronounced for a low flat area like South Florida; GTOPO30 data shows average land elevations of less than a meter in the Miami area, while SRTM30 data shows elevations of 4-8 meters. My experience with creating sea level rise simulations:

http://freegeotools.blogspot.com/2007/04/sea-level-rise-storm-surge-and-flooding.html

http://freegeotools.blogspot.com/2007/05/high-resolution-sea-level-rise-flooding.html

showed me that the building height data is not “washed out” in SRTM. Using SRTM data for a flooding simulation of Manhattan results in less flooding than using standard NED data that conforms to the ground, because the building heights skew the SRTM data. Those results are even more pronounced for a low flat area like South Florida; GTOPO30 data shows average land elevations of less than a meter in the Miami area, while SRTM30 data shows elevations of 4-8 meters.

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