GEOG 121 Project 3:
Finding, Retrieving, and Viewing National Map Data


Janet Beekman
Digital Elevation Model (DEM)

The image pictured above was rendered from a Digital Elevation Model(DEM) for the STATE COLLEGE PA quadrangle. A quadrangle is four sided and represents a parcel of land. This is not a rectangle because the lines of longitude get increasingly closer together as you head towards the Poles.

The website where I acquired the data is http://data.geocomm.com/dem/demdownload.html. The resolution of my DEM is 30-meter grid posting. This means that the area covered is split into squares that are 30 meters by 30 meters. The software that I used to create the DEM image is dlgv32 Pro(Global Mapper) and Microsoft Office Picture Manager. I used dlgv32 Pro in the lab in 208 Walker and also from my office desktop computer. A DEM or Digital Elevation Model is a digital image of a quadrangle of land where the elevation is highlighted. Looking at the center of the DEM image you see a dark area. This is where downtown State College and Penn State are. This is a low area and this is the valley in "Happy Valley". The brownish yellow area to the right of the middle is Mount Nittany. I can see Mount Nittany from my bedroom window. The brownish yellow area at the bottom is Tussey Mountain. The blue lines represent areas where there is water.

Digital Line Graphs (DLG)

The image pictured above was rendered from the four Digital Line Graphs(DLG) files that are available for the State College East PA quadrangle: boundaries, hydrography, roads, and railroads. There were several for each category for the State College East PA quadrangle. I selected one from each category where they overlapped to make a more interesting DLG. The website that I acquired the data from was http://edc.usgs.gov/geodata. The software that I used to create the DLG image was dlgv32 Pro (Global Mapper) and Microsoft Office Picture Manager. The DLG shows the area to the east of State College. If you follow route 192 east from State College you will come to a nice park called Half Way Dam. There is a beach and a place to go swimming, although the water is very cold. There are picnic tables and some grills to cook on. This is a nice place to go for a Saturday. Route 45 east of State College goes past the Elks Country Club and through the area called Penns Valley. Here there is a cave called Penns Cave which is also a nice place to visit.

Digital Orthophoto Quarter Quadrangle (DOQQ)

The image pictured above was rendered from Digital Orthophoto Quarter Quadrangles(DOQQ) data for state_college_pa_sw quarter of the State College PA quadrangle. In the upper right quadrant of the DOQQ image is the Valimont area. If you zoom in on this section of the DOQQ image using dlgv32 Pro (Global Mapper), you will see the top of my house. The website where I acquired the data is http://www.pasda.psu.edu. The date of the DOQQ is 10 October, 2004. The software I used to create the image was dlgv32 Pro(Global Mapper). At the top of the DOQQ image, you can see Beaver Stadium and Penn State's out door track. If you zoom in on the upper left quadrant of the DOQQ image, you will see Penn State's University Park campus and downtown State College.

Sources
DiBiase, David (2002) Understanding Geographic Data. Module 3: Aerial Photographs and Planimetric Data, and Module 4: Elevation Data. ESRI Virtual Campus http://campus.esri.com Accessed 10 October 2004.
GeoCommunity (2004). Think Burst Media, Inc. http://data.geocomm.com/dem/demdownload.html Accessed 10 October 2004.
The Pennsylvania State University and Pennsylvania Geospatial Information Council (2002) Pennsylvania Spatial Data Access. http://www.pasda.psu.edu Accessed 10 October 2004.
United States Geological Survey (2002) dlgv32 Pro Viewing Software. http://mcmcweb.er.usgs.gov/drc/dlgv32pro/ Accessed 10 October 2004.
United States Geological Survey (2002) Geographic Names Information System. http://geonames.usgs.gov Accessed 10 October 2004.
United States Geological Survey (2002) USGS Geographic Data Download. http://edc.usgs.gov/geodata/ Accessed 10 October 2004.