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. First you need to find
data that is at a high enough level of resolution to be useful.
You may need elevation, hydrologic unit, streams,
and roads. Anything else you can think of? What's the difference
between a stream and a river? What scale was the feature layer mapped
or digitized at? Be sure to collect any METADATA that you can find!!!!!
Get 1:2,000,000 data and compare it to 1:100,000 and
1:24,000 data for at least 1 data set (ie, roads, highways, streams,
rivers...)
Try these sites:
Metro
NW GeoData Clearinghouse
Oregon GIS
Service
US Geological
Survey
US Census
Geospatial Clearinghouse
Network
GIS Data Depot
Can you think of some other potential sources? Characterise
all of these sites by scientific usefulness.
Now that you have downloaded some data files, you
may need to convert them into a format
that ArcView can understand. You may also need to get them all into
the same projection so that you can overlay them. Remember that
we're going to work in the UTM projection! Use the Projector!
tool in Arcview to do this. You might this DEM
page useful for dealing with Digital Elevation Model data.
If there is any documentation (metadata) associated
with coverages you download, be sure to save it along with the data.
Write a detailed report of how you accomplished the
above tasks. You should be able to re-create all of the steps without
relying on your memory. This is similar to a lab notebook in Physics
or Chemistry. Turn in your report and include the map that you made.
When you write out steps for accomplishing a task,
be sure to include some text about WHY you are doing it,
ie, "In order to view all the data layers together, I needed
to get them into a common projection, To do this I ...". Lists
of steps are sometimes difficult to follow without some explanation.