G 425/525 Field GIS
D. Percy
e-mail: percyd@pdx.edu

Summer Term

Assignment 2

Finding, downloading and reprojecting data

You will now begin to build a database of basemap information for your GPS project, trying to add useful layers to your project file. Use the area around PSU and Duniway park. First you need to find data that is at a high enough level of resolution to be useful.

You will need elevation, topo map, and aerial photo. Anything else you can think of? Be sure to collect any METADATA that you can find!!!!! Be especially careful to know the EXACT PROJECTION of any data you download. You can get other vector data (like streams) to dress up your map if you wish.

At the minimum, get a DOQ, a DEM, and a DRG.

Use these sites:

NW GeoData Clearinghouse

Oregon GIS Service

Seamless USGS NED and LandUse

Now that you have downloaded some basemap data, you need to convert your landslide data to the same projection. Sure, sure, you could let the "on the fly" capabilities of ArcMap take care of this, but it's better to do that AFTER you understand the basics of projections.

Load the ArcToolbox and under Data Management you will find Projection tools for both Raster and Vector (Features). Remember the "Import" trick!

Reproject your NED from DD to UTM83_zone10. Same with landslides.

In the end you should have 3 copies of your landslides in DD, ORSP and UTM83. Each will overlay with a different set of base data.

Answer these questions and turn in the following products with figure captions and a brief description of each in a well-organized document. Turn in a printed copy.

  1. Map from assignment 1 (Include an introduction and brief overview of how the map was produced)
  2. Three maps from Assignment 2 (DOQ, DRG, DEM) with landslides.
  3. What are the major differences between raster and vector data?
  4. What are some uses for each?
  5. What are the key ideas in classification? Discrete vs continuous data? Give examples from an area that you are interested in or your work.
  6. What is scale and why is it important? Use examples from your maps.

 

updated: June 23, 2008