Case Study: Noise Maps

A noise map is a graphic representation of the sound level distribution. Noise maps are used for calculating the areas affected by noise, determining the number of sensitive buildings affected by high noise levels, getting noise prediction models. The spatial database and spatial analyzing tools of GIS is useful to monitor the effect of noise and its impact.

European Union Member States are required to produce strategic noise maps in their main cities.

What are the necessities for a noise map?

3D city model of the area

Software packages: ARCVIEW/GIS, (ArcMap, Spatial analyst, 3D analyst, and ArcScene extension), standard noise calculation software, Point Cloud Mapper (PCM), FIELDS

The steps for 3D noise maps:

Step 1: Collection of data

Step 2: Building 3D city model, extracting and organizing the data about the objects of the 3D city model for noise calculation.

Step 3: Generating the 3D noise observation points and building 3D noise model.

These observation points represent location of virtual microphones where the noise levels are to be calculated. The acoustic indicators can be determined by computation or measurement methods. However, computation methods are widely preferred. Noise levels are calculated at each observation point by using noise calculation software.

When results are obtained, spatial interpolation was applied to give a continuous graphical representation of sound levels by using GIS tools.

3D noise map shows the volumetric view of noise levels on the road surface of study area.

These are the 3D noise map and noise contours of the Delft. Inhabitants on lower floors are more affected than on upper floors.

The size and position of noise barriers can be decided most optionally using 3D noise models. Higher barriers located close to the road are more effective to prevent the noise.

For more information about noise maps:

http://www.navcon.com/citynoisemap.htm

For Delft noise map:

http://www.gem-msc.org/Academic%20Output/Kurakula%20Vinay.pdf

For Paris noise map:

http://www.v1.paris.fr/commun/v2asp/fr/environnement/bruit/carto_jour_nuit/cartobruit.h

SOM – San Francisco Digital Model

Stakeholder  & Developer: Skidmore, Owings & Merrill, San  Francisco

 Process of SOM ‘s Digital Model

With over 20 ongoing projects in the Bay Area, SOM San Francisco decided to create  a 3D Model of the city to better understand and analyze the complex environment of the City.

The creation of SOM’s digital model began with an analysis of historical and present-day maps. The underlying structure was City of San Francisco’s Geographic Information Systems (GIS) database, for this reason, 3D model would correspond directly to the 2D GIS data to simplify overlays of new geospatial data and future changes.

Because the GIS data is 2D and not intended for 3D visualization, the team then redefined the geometry of the streets and blocks to facilitate 3D operations. SOM created a curvilinear contour model of San Francisco and draped the 2D street grid over it, resulting in a 3D representation of the streetscape. The intersections were subsequently leveled automatically.

With this 3D groundwork in place, SOM then focused on the buildings. Because no database existed with comprehensive information on the City’s buildings, the team referred to aerial photographs, leasing plans, and design drawings to draw 2D outlines of building masses on appropriate parcels. Those outlines were projected onto the sloping ground planes and extruded vertically to create 3D buildings. Some of the buildings are simple box-like forms, while others are modeled in great detail.

The metadata is periodically checked for accuracy by two individuals in SOM’s Digital Design Group and linked to outside resources such as the city assessor’s office.

Model Use / Model User

Wind analysis 

The model records lot numbers, zoning restrictions, and other variables that SOM can use to create specific views to analyze issues like environmental conditions and their effect on existing and potential infrastructure. Moreover, the model is being used by the city planning department of SF to visualize potential zoning changes and development proposals.

City’s current height limits

Certainly, the digital model of SF is a good example how  create and how use a urban information modeling.

 More Information

SOM

Architect Magazine

By Soledad Hernandez

3D Ripper DX

Although my presentation focused on all forms of translating 2D data into 3D info for modeling cities and buildings, I want to focus on this one.

With the (DirectX version) you can go to Bing maps and rip the mesh data off of your graphics card. . It comes as a mesh into 3ds Max or Maya. The graphics card will read everything in the scene which sometimes gives you some unnecessary information that can be cropped away in the 3D program. Older versions of DirectX and software rendering engines do not support 3D Ripper DX.

I think this was developed for ripping game scenes but it has been successful in getting full models of cities from Bing maps. I have been told that you should find the old developer version of Bing maps though to make this work best. I have attached the best YouTube videos that show how the program works but there is song attached by the original creator, so turn the volume down and the second video shows the tutorial twice.

There is also an alternative for OpenGL which I believe Google Earth uses. I wish I knew more about this but I have only been informed about Bing and will look into this as I move forward this semester.

To use, you must download the 1.8 or 1.8.1 version. Open 3D Ripper DX, pick the executable program you would like rip from and then specify parameters. The website below can give you some more details.

http://www.deep-shadows.com/hax/3DRipperDX.htm

Project 1: Case Study

The first project this semester is a short case study presentation on a matter relevant to Urban Information Modeling.  Consider the presentation from last week which introduced projects, software, hardware, standards, cities, etc.  Select from something you saw or something new you have discovered.

Please bear in mind that this is not necessarily the same as the type of project you are going to do.   However they might be related some how or another in the end.  For example, you may do a case study on a standard such as cityGML, and you might decide to use it to help organize a custom data structure for your project.  Another example would be to select a city, almost any major city will have one or more examples (like those in recent lecture) of projects or initiatives to model the city.  Topics may be historic, contemporary or progressive in nature.

Potential topics

Please select a topic and prepare a 5-10 min presentation which explains the problem and solution spaces pertinent to the topic.  You may work in small groups, in which case multiply the length above by the number in your group to determine adequate length.

Due for presentation in class 2/10/2012