Unleashing power of GIS/GPS

TFI Learning's Conference on Unleashing the Power of GIS and GPS
March 6 and 7

Presentations of
Sandra Lach Arlinghaus

Internal links will be used in the presentation.
External links offer participants selected opportunities to continue learning.

Materials also housed at the following site: http://www-personal.umich.edu/~sarhaus/AAG/C1027_GIS_TFIWorkshop/

Introductory Remarks:

A wide variety of applications of GIS and GPS will illustrate the power of the software and its capability in municipal and other important settings. Each of you will also have the capability to interact directly with a number of the applications. Software is best mastered by working directly with it under the guidance of those who can offer immediate help. If you have a question--ask! Do not hesitate--we are here to help!
Independent of the particular application, however, keep in mind that any software is a moving target. Look for concepts behind the applications of the software. Compare and contrast the applications as they are presented and as you interact with them. Create your own set of concepts: as a sample, here is a set of concepts that has been helpful to me.

scale	hierarchy	transformation	orientation	distance	geodesic
adjacency	connection	minimax	absolute/relative	centrality	density
partition	separation	diffusion	dimension	position	interaction

The National Geographic Society identified "five themes" of geography as a way to structure concepts fundamental to geography. The initial target audience was secondary school teachers as an aid to establish somewhat standardized curricular goals. Many other people seem to find this set helpful, as well:

Location

Place

Human/Environment
Interaction

Movement

Regions

There is no one "right" set of concepts; create your own, and modify it as needed. The key is to think conceptually about applying all the wonderful tools that are currently available, and that will become available. Unleash the power! Use concepts to organize thought processes and acquisition of technical capability!

Latitude and Longitude:

Earth-sphere geometry: Link
Blackboard demonstration: longitude angle measured in the Equatorial plane above and in a small circle here. Identify basic concepts as we go along.
HANDS-ON: Open ArcGIS and see where latitude and longitude, and related ideas such as distance, come up there.

3D Atlas of Ann Arbor:

GIS has extraordinary capability, as previous demonstrations illustrate clearly, all on its own.
Using GIS in concert with other software provides even more ways to unleash its power:

With extensions from ESRI.

We will use some in the HANDS-ON section.

With plug-ins to the GIS from others.

Clickable interactive maps can be quite interesting and offer extra information at a click. The two samples below were made using the ImageMapper extension to ESRI software from Alta4.

Map of the Downtown Development Authority (DDA) area, Ann Arbor: Link
Map of the DDA with underlying aerial: Link

With other programs.

The clickable maps are quite useful; still, one might imagine more. They add extra layers of information that can be brought up add, in some sense, an extra dimension to the display, to the data, and to the user interface. In fact, however, they are still two dimensional displays of information. It is possible, however, to begin with a GIS map and export that file in a format that is three dimensional and that allows user interactivity. That file can then be imported into other software designed primarily for creating fine virtual reality files with photographic textures, animations, hyperlinks, and so forth. A screen capture of three such virtual reality models, animated to show a flood scenario in downtown Ann Arbor is displayed below.

Click on this link to enter the actual virtual reality model and take a test drive! (Your browser must have a plug-in installed for viewing virtual reality modeling language files; here is a link to a free download for such, called Cortona. Put the attached executable file on your desktop and install it following the wizard.)
Look at the code behind the model: Link.
Click on this link to see the context for an application of this model.

The process involved in making these models is complex. Here is an overview of the entire process. Participants will then work, in the HANDS-ON section, on the first step in the process (but perhaps the most important one).

Digitize all structures in Ann Arbor, from aerials flown every five years by the city, making sure not to include the rooftops or the building shadows in the digitized files. Do a pilot study to check for systematic error; isolated error will occur but systematic error should not. Digitizing was done in ESRI software with Spatial Analyst Extension and 3D Analyst Extensions installed. Export the 3D files in ESRI software to VRML 2.0 format (Virtual Reality Modeling Language).

Obtain heights for all structures in Ann Arbor.

Assessor´s data and Planning data.
Field-check UM building heights of buildings with substantial basements.

Obtain photographic textures of all structures in Ann Arbor: use a camera on a tripod for pilot study and a cherry-picker down the street centerline, or some such, for the entire city.

Clean photographic images (Adobe Photoshop was used for this entire process):

Stretch isosceles trapezoidal images to rectangles to fit building faces.
Remove foreground (use clone stamp tool)

Create realism in the model (Autodesk 3D Studio Max was used for this process):

Apply photographic images to all structures.
Model buildings with interesting rooflines.
Add street furniture and other items to model a more realistic streetscape.
Insert links to information about building interiors.
Insert audio files with directional bias if desired.

Obtain GPS coordinates of buildings as needed for Google Earth purposes.
File size consideration; layering of model with kiosks to link one layer to another-show different levels of detail at different scales.
Municipal authorities can alter the vrml code (sample displayed above) directly in WordPad if given files that have come through this process.

What concepts do you see underlying these models?
A variety of rich software packages were used in an integrated fashion to develop these models. In what follows you will have the opportunity to see also a variety of other approaches to complex issues that integrate technique and technology.
HANDS-ON: Use of ArcScene

To digitize building footprints from an aerial: digitize the base of the building, watch for shadows and rooftops--illustation with Stadium.

How precise is this process? It is labor-intensive but inexpensive if one has the aerials and maps.
Extrude the footprints and create a 3D image.

To export to vrml and view in browser.

There are ways to bring positional information into a GIS other than digitizing images. The next section will be devoted to that activity!