Black and White Aerial Photography

http://www.jaha.org/edu/flood/rebuild/img/panoramas/index.html

Most all early aerial photographs were only taken in black and white. However, these types of photos are limited in their usefullness to analyze specific data about an environment because it can only depict shades of gray between black and white. Areas in the photograph with certain similar light wavelengths will appear muddled together. There are still uses in modern technology for black and white filters when using infrared imaging and other devices. These filters block out certain undesired wavelengths according to the required specifications. This photograph (1950) shows downtown Johnstown, Pennsylvania. It represents a series of photographs which show its rebuilding after a flood in 1889. You can see the artificial embankments used to protect the downtown area from future flooding of the river.

Infrared Aerial Photography

http://www.deltanationalpark.org/tag/tourism

Infrared aerial photography is a powerful tool that can be used to monitor and track a wide array of phenomena's.  It can be used to document changes in the environment as well as monitor toxic chemical spills and track its outflow. Both infrared film and infrared sensors are sensitive of a certain portion of the spectrum of light and the use of specialized filtration and films increases the amount of data that is able to be collected. Red tones are associated with live vegetation while tan or green shades show areas of dead vegetation. Various shades of green, blue or white can give hints to the composition of the ground area. Clear clean water will appear to be close to black in color. The above photograph is of Discovery Bay which is a neighborhood surrounded by channels of water. It shows what certain areas are comprised of by "reading" the colors produced by the infrared filters/film.

Statistical Map: Internet Growth Rates in Africa

http://personalpages.manchester.ac.uk/staff/m.dodge/cybergeography/atlas/census.html

A statistical map is a special type of map where the change in a quantity of a phenomena such as rainfall or population in a geographic area is indicated. The data displayed within the map can vary. Some maps can express data using grey-tones, color shading or dot symbols with the boundaries of the areas being analyzed. In this case columns are used to display the data, emerging from the nation-state itself. In the map above, different nation-states of Africa have been analyzed in regards to the level of internet growth over a one year period.

DRG: Digital Raster Graphics

https://www.e-education.psu.edu/natureofgeoinfo/c6_p6.html

DRG's, Digital Raster Graphics, are scanned images of USGS topographic maps (standard series) which includes all map collar information. They are georeferenced to the surface of the Earth and are designed to fit to the Universal Transvers Mercator projection. The map above is a portion of a DRG of Bushkill, Pennsylvania and it includes contour lines that represent elevation change. It also shows the border of two counties and a river. These maps can be used to determine the accuracy of a vector file.

DLG: Digital Line Graph

http://www.mapcruzin.com/free-geodata-shapefiles/usgs-geospatial-data-geodata-geographic-download.htm

A DLG, Digital Line Graph, is digital vector data that represents cartographic information. This information can include but not limited to topography, hydrography, boundaries, roads, and utility lines.  The data about the maps features are stored as lines, points and areas with the data being digital vector data. These maps have the ability to contain a wide variety of information depicting geographic data. This can be seen in the map above. It show a range of different data represented as different colored lines within the map or area being analyzed. I am almost certain that the yellow lines represent boundaries but the meaning of the other lines is unknown.

DOQQ: Digital Orthographic Quater-Quads

http://www.utexas.edu/depts/grg/hudson/grg360g/EGIS/final_project/spring04_projects/web_justin_reynolds/Lake%20Travis.htm

DOQQ maps, Digital Orthographic Quarter-Quads, are aerial photographs that have the geometric qualities of a map. It is georeferenced and orthorectified, which means it defines its existence in physical space and the image has been geometrically corrected so that the scale is uniform throughout.
This is done because when taking photographs at high altitudes some distortions will naturally occur. The edges of the photo the top of the "object" is not aligned with its base because of the Earths curvature and objects at higher elevations are shown in more detail because they are closer to the imaging equipment. The map above is a  DOQQ of Lake Travis, Texas where a study is being conducted to review the changing of the floodplain. From the photographic map it is possible to overlay data onto the map to show floodplains which could aid in emergency management scenarios.

DEM: Digital Elevation Model

http://www.satimagingcorp.com/gallery/dem-sahara-tunisia-lg.html



DEM's, digital elevation models, are digital models or 3-D representations of a terrains surface. They are a digital file that consists of terrain elevations for ground positions that are calculated at regularly spaced intervals. They used a raster format and their features are tied into a coordinate system, a datum and a map projection. In raster format, the data is recorded, stored and processed in a cell or pixel. The image above is a 3-D sectional representation of the Sahara Desert in southern Tunisia. You can clearly see the elevation changes from the 3-D format and the use of contour lines. As the name implies this style is used to display the elevation of a terrain in digital format.

Stem and leaf plot

http://ellerbruch.nmu.edu/cs255/jnord/stemplot.html

Stem and leaf plots are another data analysis method that shows the frequency with which certain classes of values occur. It is a device used for presenting quantitative data in a format which is easy to read and analyze. It is very similar to a histogram and assists in visualizing the shape of a distribution of data. The example above is showing a series of 4th grade test scores. The values on the left of the vertical bar represent the "stem" while the values on the right represent the "leaf". Instead of having to list all the grades individually, the stem and leaf plot can show them grouped together. To read this type of plot you take one stem value and pair it with one corresponding number to its right. In the last column for exampled the grades are seen as: 96, 97, 98 and 99.