GEOG 4/575 Lab 3. Data File and Geodatabase Structures
Due Oct 21 before class.
Descriptions:
This lab allows you to explore different ArcGIS/ArcInfo data layers and their file structures. You will also learn to use personal (or file-based) Geodatabase to manage GIS data layers and access various online GIS data sources. Finish all tasks in Chang's Chapters 3 and 5 and submit answers to the questions at the end of this exercise. Lab exercise data are available in: I:\Students\Instructors\Geoffrey_Duh\GEOG4575\Chang_5e\chap3 and chap5 (or on the textbook CD). Please copy all these folders to your working directory in c:\Students before you start.
Please read the directions below carefully. They provide the updates to the instructions on the textbook.
Directions:
* When working Arc/Info and coverages, please make sure that the file path you use doesn't contain spaces. Arc/Info cannot handle file paths with spaces.
* Chapter 5, Task 1. ArcGIS 10 can decode a raster STDS catalog/directory data descriptive file (XXXXcatd.dff) and open the data (cel0.ddf) associated with the catd.ddf file. You will need to change the symbology, which activates the calculation of raster statistics, to view the image. Once the data set is added to ArcMap, you can use the export option of the layer to save the file to other formats.
* Please note the discrepancies between ArcGIS 10 and the descriptions in the textbook. Try to locate the key information described in the textbook on the Graphic User Interface (GUI) of ArcGIS 10.
* You can use the 7-zip program to unzip compressed file with .tar or .gz file extension names.
* There is no "Tool" menu in ArcGIS 10's main menu bar. You can find the "Customize mode..." tool in the "Customize" menu and the "Add XY Data" tool in the File menu, under the "Add Data" submenu.
* ArcGIS has a completely redesigned editing environment. To follow instructions described on the textbook, you need to check the "Use classic snapping" option on the Option dialog window of the Editor menu (on the "General" tab). Then, you can find the snapping setting dialog windows from the "Snapping..." submenu on the Editor menu. Please do explore the new snapping environment in ArcGIS 10. In most editing modes, you can double-click to complete an editing task.
* Chapter 5, Task 4 shows you how to access data from an ArcIMS service. ArcGIS 10 also has several ways to add online data. "Add Basemap" tool lets you add predesigned online maps that do not require frequency changes. "Add Data from ArcGIS Online" tool provides an easier interface for accessing online map contents. The CSAR ArcGIS Server also has some datasets that might be useful in your project. Please follow this link to access the data on the CSAR server. When using online data, patience is a necessary virtue. Don't expect the computer will render online data as fast as local ones.
Questions:
1. Illustrate the differences in data file structure between a coverage, a geodatabase feature class, and a shapefile. (Hint: Use Windows Explorer to view the data layers you used in this exercise and see how they differ from each other.
2. Are feature classes in a feature dataset allowed to have different projections?
3. You have a polygon shapefile (e.g., census block) containing only population information (i.e., without area data of the polygons). Describe the steps to calculate the population density in each polygon.
4. What is the difference between a route and a regular polyline (or an arc) in ArcGIS? Can a route represent a path that is not physically connected from the beginning to the end (e.g., Washington State Highway 20)? Give an example of what such routes might be.
5. Imagine that you have acquired a missing notebook from the Lewis and Clark expedition that has the latitudes and longitudes of all of the camas wetlands they encountered along the Columbia River. Each entry has detailed notes that could be used to populate an attribute table. How might you create a shapefile with associated attribute table for these camas fields? List the steps you would take.