Transcript GEOG 121 Project 3 By: Fiana York Megan Wallace Dustin Dodd

GEOG 121 Project 3
By: Fiana York
Megan Wallace
Dustin Dodd
Thomas Hood
Introduction
Objective of project 3 is to:

Demonstrate your ability to find, download,
comment, and view national map data
3 different types of national
map data used in this project
Digital Elevation Model (DEM)
Vector Layers or Digital Line Graph
(DLG)
Digital Orthophoto Quarter Quadrangle
(DOQQ)
DEM
Digital elevation models that show
elevation
Based on topographic maps
Usually DEMs are made by
photogrametry, from aerial photos
How to find a DEM map
Go to http://edc.usgs.gov/geodata/
Under “1:250,000 Scale Digital Elevation
Models (DEM)” click on Alphabetical List
Find a DEM Map in one of the folders and
then “Save to Disk”
Double Click on it on the Desk Top
It should then open up Win Zip. Then Press “Use Evaluation Version”
How to find a DEM map
Open the Archive using the “Classic
interface” then press ok
Double Click on your file and then you should
get a screen with a lot of numbers go to File
then save it to the Desktop.
Go to Start, Programs, Geog 121, and then
dlvg32
Drag the file saved on the desk top onto the
dlvg32 Pro program
How to find a DEM map
(Cont.)
It will ask what overlay you want. Click
on USGS/CDED DEM.
It should look like this of your area.
DEM map (cont.)
Now you need to make sure the dlvg32
program with your DEM map on is
selected.
Press “Alt-Print Screen.” That will copy
the program that you have active as an
image. Proceed to either Word or
FrontPage and “Paste” (It eventually
has to go to FrontPage anyways.)
Completing the DEM map
Under the image you will need to include the
following information:





the area covered by your DEM
where you acquired the data
(http://edc.usgs.gov/geodata/)
the resolution of your DEM (If you used the above
link it should be 10)
the software you used to create the image (dlgv32
Pro)
your comments on the landforms revealed in the
DEM
DLG
 DLG graphs are made up of points and
line segments that connect the points

An area is formed by 3 or more segments
DLG Cont.
DLG shows:




Hydrography
Transportation data
Political boundaries
Exc.
How to find a DLG map
How to find a DLG
(digital line graph
map), we used the
website:
http://arcdata.esri.c
om/data/tiger2000/ti
ger_download.cfm.
How to find a DLG map
Pick your state, county, and the
different overlaying options (Line
Features: roads, hydrography,
landmarks, etc.)
Once you do this, download the file and
use WinZip to unzip your files.
What you’ll need in the write
up
discuss the following points in your writeup:
1.
2.
3.
4.
5.
Area covered by Map
Where you acquired the data
Types of Map layers (ex.Boundaries,
transportation, hydrography, etc.)
Software used to create the map
Comments on the Types of entities represented
by Vector data (Example: Why you chose certain
colors to represent certain things).
* NOTE: It is
difficult to open the
files into ArcMap, so
we just dragged the
Highlighted box (in
the middle with the
A) into ArcMap, and
it opened up just
fine.
DOQQ
Are raster images of rectified aerial
photos
Only covers a quarter of an area of a
topographic quadrangle (3.7 min. of
latitude and longitude)
DOQQ cont.
They are produced by electronically
scanning, then orthorectifying black and
white aerial photos
Used to edit existing vector data
All DOQQs are cast on UTM projection
Zones
90% of well defined points appear
within 20ft of there actual position
How to find a DOQQ image
Go to
http://earthexplorer.usg
s.gov

Log in as guest
Under the “Spatial
Coverage Section” enter
in the coordinates of
your hometown (or
search for them within
the earth explorer)
DOQQ image (cont.)
Select data set and under Arial photography
select the Digital Orthophoto Quadrangle box
Now click continue and then search
When the results come up click “show” to
view an image
Pick a DOQQ and save it in your www folder

Now its ready to be put directly into your project
write up
Sources
DiBiase, David (2006) Understanding Geographic Data. Module 3: Aerial Photographs and
Planimetric Data, and Module 4: Elevation Data. ESRI Virtual Campus
http://training.esri.com Accessed October, 2006.
The Pennsylvania State University and the Pennsylvania Governor's Office of Administration,
Office for Information Technology, Geospatial Technologies Office (2006) Pennsylvania
Spatial Data Access - Data Access Wizard. http://www.pasda.psu.edu Accessed October,
2006.
Environmental Systems Research Institute (ESRI) (2006) ArcGIS - ArcMap Software.
http://www.esri.com Accessed October, 2006. Note: ArcMap software is installed in
the Geography Instructional Computing Laboratory in Room 208 Walker
Building.
Environmental Systems Research Institute (ESRI) (2006) ArcExplorer Software.
http://www.esri.com/software/arcexplorer/index.html Accessed October, 2006. Note:
ArcExplorer is a freely downloadable simplified version of ArcMap.
United States Geological Survey (2002) Geographic Names Information System.
http://geonames.usgs.gov Accessed 23 July 2002.
United States Geological Survey (2002) USGS Geographic Data Download.
http://edc.usgs.gov/geodata/ Accessed 3 August 2002.