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]> 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 )
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
Technologies is managed by www.iapad.org and hosted by www.ppgis.net
PGIS, PPGIS and community mapping bibliography is found at http://
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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)
t. +31-(0)-641639088 (Mobile for Holland)
e. [EMAIL PROTECTED] or [EMAIL PROTECTED]
w. http://www14.brinkster.com/tningal
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