tag:blogger.com,1999:blog-179325926611299376.post1101028669053509699..comments2023-09-16T13:46:11.986+01:00Comments on Open Maps: Extracting building heights from LIDARChris Hillhttp://www.blogger.com/profile/02951528269028953589noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-179325926611299376.post-26424896919996189242015-12-01T22:35:24.119+00:002015-12-01T22:35:24.119+00:00thanks for grea postthanks for grea postjhonhttp://www.sinwaxtechnologies.comnoreply@blogger.comtag:blogger.com,1999:blog-179325926611299376.post-11037987749404386222015-10-08T19:53:40.577+01:002015-10-08T19:53:40.577+01:00Chris, I met with the Mappa Mercia group last nigh...Chris, I met with the Mappa Mercia group last night and we agreed that we'd be interested in the Worcester data (I've checked and it looks like there is data available there). As per your kind offer above can you please send me a copy of this when you have the time to do the required processing. My emails on the mailing lists (example: https://lists.openstreetmap.org/pipermail/talk-gb-westmidlands/2015-October/001910.html ). Thanks. RobJNRobJNhttp://www.mappa-mercia.org/contactnoreply@blogger.comtag:blogger.com,1999:blog-179325926611299376.post-19335831433439602972015-09-29T09:26:31.888+01:002015-09-29T09:26:31.888+01:00@Martin, the first release used a spurious precisi...@Martin, the first release used a spurious precision to less than the diameter of an atom. They fixed that now to 3dp of a metre. Chris Hillhttps://www.blogger.com/profile/02951528269028953589noreply@blogger.comtag:blogger.com,1999:blog-179325926611299376.post-87249395341783907642015-09-29T07:35:13.740+01:002015-09-29T07:35:13.740+01:00I think the accuracy is around femtometers ... (-:...I think the accuracy is around femtometers ... (-:<br /><br />http://rapidlasso.com/2015/09/02/england-releases-national-lidar-dem-with-insane-vertical-resolution/Martin Isenburghttp://rapidlasso.comnoreply@blogger.comtag:blogger.com,1999:blog-179325926611299376.post-1215870144457971002015-09-28T18:28:36.647+01:002015-09-28T18:28:36.647+01:00The data is supposed to be to the nearest millimet...The data is supposed to be to the nearest millimetre. I think the process is pretty robust and finds the highest point of each building pretty reliably, but I would be conservative and use the height to the nearest cm which would be perfectly usable. The height=* tag expects the highest point of the building.<br /><br />There is a lot of data to process; 1 km² needs 1 million database rows. Hull, a moderate city, needs about 80km². This is temporary data, but nonetheless I can't imagine me creating data to cover much of Britain. The process needs existing building outlines to compare the heights to and the EA data does not cover all of Britain - it is intended for flood assessment.<br /><br />Are you intending using any of it? Would you like an area (say 1km²)to test?<br />Chris Hillhttps://www.blogger.com/profile/02951528269028953589noreply@blogger.comtag:blogger.com,1999:blog-179325926611299376.post-3975499397861452512015-09-28T18:15:46.843+01:002015-09-28T18:15:46.843+01:00What level of accuracy do you think you are gettin...What level of accuracy do you think you are getting? How far is it possible for you to process the data then hand over to someone who has the time and energy to explore the import side of things?<br />RobJNUnknownhttps://www.blogger.com/profile/18392907547759726319noreply@blogger.com