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Objectives
Virtual reality can enormously benefit sustainable urban planning
over a long period of time. Effective visualization considerably
relies on relevant and contemporary data, capabilities of interaction
and analysis, and involvement of participants in the planning process.
The goal of this work is to develop such visualization application for
coastal cities by Lake Michigan in northern Indiana. To achieve this
primary goal, a number of supporting objectives must be accomplished in
this study. First of all, we will develop an effective 3-D data (in
particular buildings) collection technique. Such data is essential for
urban planning in terms of visibility analysis, cultural and natural
heritage reservation, noise and pollution modeling, and tourism
industry. With the proposed development, we will be able to provide 3-D
building models over selected interest areas at the proper levels of
details. As for the second objective, we will develop highly automated
method to derive land cover maps for coastal zones (the area from
shoreline, marsh, sand to the city land boundary and near shore areas).
This effort will provide the most recent and accurate coastal zone
information for Indiana, which can then be used along with historical
coastal information for coastal change modeling and prediction. The
third objective is to provide interest users with the capabilities to
interact, modify, manipulate, and demonstrate the views such that
different design scenarios and modeling results can be evaluated. In
summary, the outcome of the proposed study will be virtual cities over
the selected areas that will meet a variety of needs in urbanization
modeling, water resource planning, fishery industry, and ecosystem
protection, and ultimately benefit long term sustainable economic and
environmental development in the coastal areas in northern Indiana.
Methodology
The proposed methodology consists of three tasks: 3-D building model
generation, coastal mapping, and visualization. The Indiana 2005 DSM,
DEM and ortho images will be used for this study. For building model
generation, we propose a clustering approach based on dimensionality
evaluation to determine the points on the same planar roof. To obtain a
reliable solution, we will adapt the density based clustering
approaches, where each data point is given a potential based on its
neighboring points, and the point with the highest potential is
considered as the cluster center. In the last step, building component
boundary will be traced by using a modified convex hull algorithm and
reconstructed by enforcing certain regularization constraints such as
perpendicularity, parallelism and symmetry.
As for coastal mapping, we propose a fusion based
classification solution. First we will create the DFM (digital feature
model) by subtracting DEM from DSM. The resultant DFM and/or its
derivatives will participate in image classification as additional
‘texture’ bands. Such texture bands can be standard deviation, slopes,
curvature, co-occurrence matrix, or spectral decomposition such as
Fourier or wavelet transforms. As different objects have different
textures, the inclusion of these additional bands into image
classification will enable us to further separate spectrally similar
features. Finally, all the feature classes derived from classification
will be vectorized by using modified Douglas-Peucker methods followed by
a regularization process.
Both the 3-D mapping and 2-D mapping results from the above steps
will be integrated into Google Earth for evaluation and presentation. We
will customize Google Earth such that sitespecific social-economic and
planning data can be combined with the basic geospatial data or
information extracted through this study to build a virtual coastal
city. In addition to standard Google Earth capabilities, the development
and enhancement will also allow users to easily access relevant data
providers and servers, and support on-line digitizing, editing and
labeling interest features.
Rationale
Lake Michigan has about 110 miles of heavily urbanized and
industrialized shoreline in the states of Illinois and Indiana. During
the past 30 years, this region has become one of the top three most
populated areas in the country. Such accelerated development demands a
long-time and effective strategic planning for the limited land and
water resources. Sustainable development is crucial for citizens, policy
makers, and urban planners in this region. Realizing the above urgent
need, the state Indiana plans to achieve, manage, and maintain
sustainable development for its coastal cities along the shoreline of
Lake Michigan.
Both planning and subsequent implementation highly rely
on the availability of various social, economic, and geospatial data at
different resolutions; the capabilities to integrate, access and
visualize them effectively; and the support on interactive scenario
analysis for decision makers and the public. However, at present, most
of activities in planning and its implementation are based on 2-D
geospatial data and 2-D landscapes, much of which is also actually not
up-to-date. As a result, urban planners and their guests must often pay
field trips to visit places that they can not interpret very well in
offices. This substantially increases the planning cost and delays
planning progress since many places by the coast are not easily
accessible due to transportation difficulties. Moreover, current
planning outcome is mostly presented in 2-D environment and lack of
realistic perceptual effect. One may not be able to fully evaluate and
appreciate the future city that they have designed or expected. Finally,
citizens can only at present time be presented with 2-D paper map or
display. It is impossible for them to be fully and actively involved in
different stages of planning and its implementation, which hampers the
citizen’s participation, involvement and awareness in public affairs,
and may even retard the effective communication between the local
government and its citizens. |