Overview
Data Structure
Digitizing
Data Entry Errors
Level of Effort
Error Analysis
Metadata Report
Future Mapping

Data Structure

In order to collect the data as efficiently and compactly as possible, we established two feature classes and one look up table.  We put these elements into a Personal Geodatabase.

Buildings Layer: Feature class—Polygon

Street Centerline: Feature class—Line

Land Use Table

How robust your did the database design proved to be? Note: this is based on the challenges we ran into during digitizing feature classes (Week 3).

Regarding how robust the database design is, referenced to the Week 1 and Week 3 projects, we divide it in two parts: 1) Operation Aspect, and 2) Information Aspect.

1. Operation Aspect

Here, one of the most important things to consider to make robust a database design is the operation performance aspects explaining right now why. To make robust this part, first, it depends of how projected could be a displayed area (in this case, the orthophoto) because if a photo is not projected, the information we’ll obtain could be erroneous. Other way here in the design operation is establishing the X/Y Domain as a result of the challenges we spent when we digitized the feature classes because in this case, the X/Y Domain must be according to the projected photo. If certain element at the Display Area is not present just as the cartographic projection, it should weaken the design process.

On the other hand, other thing can robust and/or weaken the database design we desire to include also is about georeferencing errors. In this part, we think it’s important to emphasize that, foe the database design, we must have a right georeferencing because, at the moment of digitizing, several maps could not be in a correct way and, indeed, in digitizing errors once the maps are already digitized. Finally, and most important in the database design, are the parameters we established when we add the fields for the design of the attributes of the feature class. One found error at the moment of the design process is that we must take care in establishing the field parameters (i.e.: Text, Short Integer, Long Integer, etc) because sometimes when a person is entering a data in the feature’s table in the editing process, it could give an error message because the parameters were not well established at the beginning and that is one of the errors that weaken the database design.

2. Information Aspect

This is the other aspect about how robust can be the database design. Summarizing this part, we can conclude that some of the information located in the map were not established (i.e.: buildings with no addresses, no building’s name, more that one street and no obvious delineation of how to segment the address to a portion of the building among other problems). In this part, simply it is that if there was no information in the map, then, we could not put anything in the tables.

GEOG 5223: Elements of GIS: Part 2 (ESRI Track) CD. Accessed September 2004.

How to Read Sanborn Fire Insurance Maps, University of Virginia Library website. http://fisher.lib.virginia.edu/collections/maps/sanborn/web/details.html.  Accessed September 2004.

GEOG 5223: Project 7, 8, 9 & 10: Final Project, Accessed September 2004.