GEOG 121 Project 3

By: Fiana YorkMegan Wallace

Dustin DoddThomas 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 elevationBased on topographic mapsUsually 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 ListFind a DEM Map in one of the folders and then “Save to Disk”Double Click on it on the Desk TopIt 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 okDouble 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 dlvg32Drag 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.com/data/tiger2000/tiger_download.cfm.

How to find a DLG mapPick 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 write-up:

1. Area covered by Map2. Where you acquired the data3. Types of Map layers (ex.Boundaries,

transportation, hydrography, etc.)4. Software used to create the map5. 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)

DOQQcont.

They are produced by electronically scanning, then orthorectifying black and white aerial photosUsed to edit existing vector dataAll DOQQs are cast on UTM projection Zones90% of well defined points appear within 20ft of there actual position

How to find a DOQQ image

Go to http://earthexplorer.usgs.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 boxNow click continue and then searchWhen the results come up click “show” to view an imagePick 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.