Hello Tine,
I am forwarding your request to a group of mappers, here, that may know
of some resources for your project ( below)
Cheers-
Mike
-------- Original Message --------
Subject: Re: [ppgis] 3d geoweb - Digital Earth - reference model
From: Tine F. Ningal <[EMAIL PROTECTED]>
Hi Mike,
i My research is on modelling air quality at street level in the inner
city of Dublin. To model the the ambient air flow in the streets, a 3D
GIS is a prerequisite. That means a 3D footprint of the buildings and
street configuration. to get such a data is almost impossible and that
means one has to create the data from scratch.
I am sure there should be 3D data about this somewhere, or if not an
easier way to go about extracting the building/street forms and deriving
the height values. I have Quickbird images over the study area which is
60 cm resolution -very high. However, it would take a long time to
digitize all the building accurately as there are shadows and also,
zooming cannot go down to certain thresholds. The images are in tiles
and there is no overlap so no stereo can be acieved through
photogrammetry modules in image processing applications like Erdas, Envi
or others.
I have tried to extract heights from SRTM 90m DEM but the resolution is
big. The idea was to propagate the DEM heights to the buildings. The
only option I am left with now is to collect elevation points either
using GPS or from existing topographic maps. I am still exploring ways
to derive heights from the Quickbird images, also automatic or
semi-automatic feature extraction.
If you have any ideas, tips or experiences to share on extracting
features and height from Quickbird I would be more interested to know.
Regards and cheers
Tine Ningal
UCD, Dublin, Ireland
On 5/4/07, *Mike Liebhold* <[EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>> wrote:
Dear Friends, ( please forgive cross posting )
I've been thinking a lot about 3D GIS lately, about interoperability of
3D objects in real world - virtual worlds like Google earth, Microsoft-
virtual earth, NASA wwind, ESRI ARCglobe, companies like Autodesk have
large legacy 3D GIS &CAD systems still moving forward, and no doubt
someone like Linden Labs will launch a 3d social apps in a real world -
virtual world.. based on geo coordinates instead of 2nd life's random
geography, and even mobile 3Dgis is quickly showing glimmers of
promise: mobile augmented reality developers will likely build a
geocoded 3D frameworks to hang links on... for services like nokia's
MARA prototype ( http://www.technologyreview.com/Infotech/18291/)
... and
a consensus 3D geoweb like GEON (
http://www.geongrid.org/about.html <http://www.geongrid.org/about.html>)
will also be the basis for the worldwide sensorweb, eg. for
trans-disciplinary problem solving like macro-ecology, climate models,
zoonautic, ( animal born disease) emergency response, &&
Will we have multiple 3D geowebs? beyond harmonized 2D geodata and
geocoded hypermedia, will 3D data and media producers and service
operators have to produce and manage multiple frameworks ( including
places, buildings, things - people& avatars ) for each or these
environments?
So, following digital earth, champion, Tim Foresman's lead - (As
Director of Digtal Earth programs for NASA working for vp gore, Tim lead
the first DERM - A reference model in the Federal Geospatial Data
Committee and ISO communities in collaboration with the original NASA
led Interagency Working Group on Digital Earth. That work is now off
on a dusty shelf, out of date, given the future requirements.)
I'll be leading sessions at Where2.0
(http://conferences.oreillynet.com/where2007/) and ISDE5
(http://www.isde5.org/ ) to raise questions leading to re-starting
considering of a consensus reference specification, for a 3D geoweb - a
a standard Digital Earth. google, no doubt, sees kml as the answer to
these questions, and MS is, no doubt brewing up their own
too, clearly
the big guys are going to duke it out from very proprietary
perspectives, and it's still not clear that the US gov, OGC, W3C, OR
SIGGRAPH communities like x3D focusing on vrml, offers the integrated
perspective of the participatoryGIS, FOSS4G and digital graphic arts
communities, here, capability to develop detailed optimum requirements
from wide perspectives:
Let's start again considering, as communities, a meta level layered
architectural description for unified earth and geo-related computing,
refining a model including the following topics ( and others) into an
ideally coherent and rigorous framework for optimally sharing and using
data across all web, geospatial and scientific contexts:
* geodesics, where experts are still refining descriptions of the shape
of the earth, and where new coordinate systems are argued.
* sensor data generation and labelling
* geodata and hypermedia coding/decoding/transcoding
* open source networked geodata -libraries and feeds- of raw sensor
data, streaming media, tiles, 3D objects , 2Dvectors, polygons, points,
text, etc.)
* geo metadata models - formal ontologies, logical description, as
frameworks for mining informal users' tag systems
* geo server and middleware models for efficient saving, searching, and
sharing of all kinds of geodata
* sensemanking inference and other spatial intelligence
* rendering software for combining many sources of geodata into
unified
useful views for many kinds of interaction
* user software/ sharing/saving/serving/searching/rendering
* human interaction systems, avatars and social nets, gis, mobile gis,
3Digs, geoaudio, augmented reality, haptics
* autonomous sensor networks processing geodata.
* meta scale geosciences exploring large transdiscipline problem spaces
like planetary meteorology, large scale ecosystem modeling,
human-ecosystem interaction models, large scale, emergency
response,...
These are just penciled place holder layers of a hypothetical reference
model - that will need to be refined by the appropriate communities.
I have no idea how to organize a coherent dialog between the e-mail
list communities cc'd here. right now, maybe somewhat loosely
connected dialog will be fine. later perhaps starting at where2.0 and
ISDE5, maybe some kind of 3D geoweb wiki communities will coalesce to
start organizing these consensus interoperable models.
See you in San Jose and Berkeley!!
Mike
Mike Liebhold
Senior Researcher
Institute for the Future
The Open Forum on Participatory Geographic Information Systems and
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Tine F. Ningal
University College Dublin
College of Human Sciences
School of Geography, Planning & Environmental Policy
Richview
Clonskeagh Road
Dublin 4, Ireland
t. +353-(0)-870613344 (Mobile)
t. +353-(0)-17162677 (Office)
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e. [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> or [EMAIL PROTECTED]
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