Portolan Chart

The Library of Congress has an extensive collection of historical maps. One type of map is referred to as a Portolan Chart. These maps were used almost exclusively by mariners. They were the most detailed maps of the coast for their time period. Mariners were more interested in the coast line and potential harbors than any information that would be inland. That fact is represented by the lack of any detail and addition of artwork within areas that represent land. Notice the crisscrossing lines that dominate the background of this map. Mariners needed maps with lines that indicated compass directions to make sailing more accurate. 

Infrared Aerial Photograph

The National Parks website provides a stunning example of an infrared aerial photograph. The benefit to using infrared is the level of detail that can be obtained. This type of film is best used when photographing vegetation. As you can see, this photograph of the Lyndon B. Johnson Ranch shows a wide variety of plants and trees. It is important to remember that the colors seen on an infrared photograph are really "false" colors because the human eye can not see infrared. 

Black and White Aerial Photography

Remote sensing is very useful to mapmakers and geographers. This website from Montana State University shows an example of a black and white aerial photograph taken of San Ysidro, New Mexico. A camera is mounted on an airplane as it flies over an area the camera collects data. The human eye catches on the varying shades of grey and our minds automatically equate darker shades with depth and lighter shades with elevation. Those with the right training can analyze a black and white aerial photograph to determine what objects might be on the ground.  

Dopplar Radar

This image found at The National Weather Forecast Office is a doppler radar image of Tropical Storm Alberto. Weather stations around the country send microwave radiation out into the atmosphere and collect the returning information in order to tell a meteorologist the amount or precipitation, what kind of precipitation, and what direction the weather system is moving among other things. With this doppler radar image of the tropical storm even the untrained observer can see that the heaviest rain is in the center of the storm and that it appears to be moving in a counter clockwise pattern. Doppler Radar is very useful for predicting weather movements and developments. 

Propaganda Maps

Governments are infamous for using propaganda maps in order to influence the ways people think. In this instance, the point is to persuade those who argue they are expansionist, radical, and aggressive that it would be impossible with so many powerful arab nations surrounding them. In fact, I believe this propaganda map also attempts to elicit support by portraying them as the underdog. This map emphasizes a threat to Israel by showing how small and "helpless" it is. More information, along with this map, can be found here. 

LIDAR

LIDAR is a type of of remote sensing. Unlike radar and and sonar, LIDAR uses a laser to create images. This particular image is of Kansas City. LIDAR is often used mounted to an airplane. 

This image was provided by Rod Franklin in a newsletter for Imagenotes.com.

Star Plot

Niklas Elmqvist, John Stasko, Philippas Tsigas wrote an article that was published on Palgrave Macmillan . A start plot compares  multiple variables for one observation. This star plot compares variables about homes in Vermont such as the year built, number of rooms, and value. 

Similarity Matrix

I thought this would make things a little bit more fun. Thanks to Yu Shiu at the Electrical Engineering Department at the University of Southern California, this is a similarity matrix of The Beatles' song "Hey Jude." The two variables that are compared are Tempo and PCP. Along the diagonal they are most similar. 

Stem and Leaf Plot

Like the last two graphs posted, a stem and leaf plot is another form of frequency distribution. This is a distribution of adult heights that was taken from a sample. The column on the left is the height in inches and the columns to the right are the height in .1 inches. For example. Out of the entire sample taken there are three individuals who are 68.6 inches because there are three sixes on that row. This graph and more can be found at  the University of Mississippi website. 

Boxplot

A boxplot is very useful for statistics. A quick look provides the reader with information on the distribution of data. The box contains scores from the 25th-75th percentiles. The 50th percentile is always the line in the middle of the box. The 10th and 90th percentile are illustrated by the lines at the end of the "whiskers." This boxplot can be found at stata.com.

Histogram

A histogram is a method of displaying frequency. The x-axis is the different variable and the y-axis is the frequency. For example, this histogram shows the frequency of numbers that would come up when rolling a pair of dice for the game of backgammon. This histogram comes from the Department of Physics at the University of Toronto.  

Parallel Coordinate Graph

The Ernest Orlando Lawrence Berkeley National Laboratory provides this Parallel Coordinate graph that shows genes and cells. These graphs are useful for comparing multiple sets of data. Each line is a different variable and it is possible to connect a line between the axes. Each line represents a different cell that shows up in different genes (the axis). 

Triangular Plot

A triangular plot is useful for comparing three different variables. In this case, the triangular plot compares voting for the three different parties in the UK. Each color responds to a different winner based on the distribution of votes. This graph was found at ex-parrot.com using data provided by Anthony Wells. 

Windrose

This is a windrose for Washington state that can be found on the Office of the Washington State Climatologist wesbite. A windrose is an example of a circular plot. Each ring is a percentage and the colors correspond to a wind speed. For this windrose, the wind blew South at a speed of 4-7 Knots about 10% of the time. 

Climograph

A climograph is able to show the relationship between temperature and precipitation by using a line graph and a box plot. In this graph the bar measures the amount of rain and the line measures the temperature for Guam. The NASA website that this graph comes from puts it plainly: the climograph is useful for "making inferences about an area's climate." 

Population Pyramid

This animated Population pyramid from Flatrock shows both age and gender of the United states population. What makes this graph interesting is the animation that shows the transformation of the population over one hundred years from 1950 to 2050. Obviously this is a prediction based on current trends, but it is possible to see how the effects of advancements in healthcare can contribute to a bloated population. 

Scatterplot

A website called Radicalmath provides this scatterplot distribution to show the relationship between percentage of population and percentage of military recruitment. The direction and clustering of a scatterplot allows the reader to determine a relationship. A tight cluster shows strong relationship while a dispersed cluster indicates no relationship. A cluster pointing up to the right indicates a positive relationship while a cluster pointing down to the right indicates a negative relationship. This scatterplot shows a positive relationship between the percentage of population and the percent of military recruitment. 

Index Value Plot

On the USGS website you can find this index plot graph of stream flow between 1999 and 2006. An index value plot does not use absolute numbers. Instead, an average is taken and the start point begins at that number. It is now possible to determine from this graph when the stream flow was below or above "normal." All plotted values are relative to the index value. 

Lorenz Curve

The Lorenz Curve is most often used in economics. It can explain the distribution of income among a population like this graph, but it can also be used for other variables. This chart is very informative. The straight line in a Lorenz curve shows what equal distribution would be. The curved lines connect dots showing the actual distribution. Thanks to the breakdown provided, it is easy to understand how this Lorenz curve shows the top 25% of the population has 70% of the wealth while the bottom 25% has only 5% of the wealth. This graph can be found at Answers.com

Bilateral Chart

This is a bilateral graph of humanitarian aid around the world. A bilateral graph is useful for visualizing the effects or relationships between two related variables. In this instance the bar graph is the change of humanitarian aid in US dollars. The line graph is the percentage of change in humanitarian aid. It makes it very easy to see that despite a significant decrease in money going to humanitarian aid in the US the percentage of change is very minimal. This stands in contrast to Luxembourg where their increase in in monetary aid was very small, but the percentage of increase was very significant. This bilateral graph can be found out the Global Humanitarian Assistance website.

Google Earth

I'm always interested in maps of Malta. I was excited to play around with Google Earth and spent a couple of hours trying to find my grandfather's house in Ghaxaq. It got blurry after a certain point, so I'm assuming there isn't as much data for somewhere "remote" like this. My favorite feature of Google Earth is the ability to add photos to locations.
This map of Malta shows vegetation levels on the island. As you can see there is not much and it is concentrated inland. The Vegetation Programme uses SPOT 4 and SPOT 5 for remote sensing. More information is available here.

Digital Orthographic Quater-Quads or DOQQ

This DOQQ map can be found at Forestpal.com. DOQQ maps are areial photos that have been orthorectified. This process removes distortion, putting features in their correct position. After a photos has been orthorectified it is useable as a map.

Digtial Elevation Models or DEM

This map of New South Wales is a digital elevation model. Color is used on this map to bring out relief. Without a legend it is still possible to conclude that the red areas are highest and the blue areas are lowest. More information on this map can be found at the New South Wales Government wesbsite.

Digital Line Graph or DLG

This map found on the USGS website is a digital line graph. Unlike the DRG, these maps use vector rather than raster data. Instead of the data being pixilated the data is stored as lines, points, and areas.

Digital Raster Graphic or DRG

A digital raster graphic is a digital version of a USGS or United States Geological Survey. They are topographic maps that are 7.5 min of latitude and 7.5 min of longitude with a scale of 1:24,000. DRG's are georectified which means it has been linked to real world positions using coordinates, datum, and projection. This map came from the Illinois Natural Resources Geospatial Data Clearinghouse.

Bivariate Choropleth Map

The bivariate choropleth map shown here is using both color and proportional circle to show a relationship between the ratio of male to femal workers and the average income of male and female workers. This was found on an Intro to GIS site. Bivariate choropleth maps are thematic maps showing relationships between two variables.

Unclassed Choropleth Map

This map shows the divorce rates in the united states by area. That's what makes it a choropleth map. It is an unclassed choropleth map because it uses a continuous scale. There are as many intervals as there are areal units. I found this map on the ESRI website in a paper written by Naresh Kumar

Classed Choropleth Map

Illinois State University  offers up an additional source for anyone who is still somewhat confused on classed choropleth maps and the classification techniques used for them. First of all take a look at the legend. This map has four intervals. A choropleth map can have different intervals and the number used can change the way the map looks. Also, look at the way the interval is broken up. There are four classification techniques: Equal steps, Quantiles, Natural Breaks, and Minimum Variance. 

Choropleth Maps

The purpose of a choropleth map is to show areal data. The information is usually relating to area and is usually in measurements of square mile. Choropleth maps average area either using density or percentages. There are many types of choropleth maps. This map shows average areal distribution of orchards in the united states. It came from the USDA website. 

Range Graded Proportional Circle Map

Turning again to Rutgers, this is a classic example of a range graded proportional circle map. It is the other type of proportional circle map. In range graded proportional circle maps, only a set number of circles are used. 

Continuous Variable Proportional Circle Map

The map of Canada found at the Canada National Statistical Agency  shows a continuous variable proportional circle map. There are two types of proportional circle maps. The best way to tell this one apart from the other one is from the legend. The circles come in all sizes representing the distribution of the variable. 

Proportional Circle Map

This map provided by The University of California, Santa Barbara's geography department, is an example of a proportional circle map. This is another type of point pattern map. Notice how, unlike the dot density map from before, the circles get larger as the variable increases. This particular map shows internet usage throughout Europe. 

Dot Density Map

The University of Washington  website is where I found this map of China. Dot density maps are a type of point pattern map. Each dot represents 50,000 people. Despite the large area of China (about the same as the United States) its population is concentrated in specific regions. The coastal area is most populous because of the booming pacific rim economy. Other population densities focus around rivers. 

Flow Map

The University of Texas has a nice catalog of maps on their library website. This one is of a flow map. Flow maps show the intensity of travel along a path. As the lines grow thicker, the intensity also grows. This map shows commercial truck flows for the United States. 

Isopach Map

Isopach maps are contour maps that represent rock thickness in the third dimension. The South Florida Information Access website has this map that shows the rock density of the Florida Aquifer. 

Isohyet Map

The Hong Kong Observatory has this Hypsometric map that also shows contour lines. The contour lines on this map of Hong Kong are called ishoyets. Isohyets provide infomration on rainfall levels. 

Isotach Map

Isotach maps use contour lines to represent information on wind speed. This map shows windspeeds around Florida that are 700 millibars apart.  College of Du Page has a weather lab that provided this map. 

Isobar Map

Sidlaweather in the UK shows an isobar of Europe. Isobars are a type of contour line that shows air pressure. 

Isoline Map

Rutgers offers an example of how isoline maps are made. Isolines connect points of equal value on a map.There step by step process clarifies how to turn information on a third dimension (this one shows elevation) into isolines for a contour map. 

Contour Map

Because Contour maps are a type of hypsometric map it makes sense to use similar maps from my last entry to show the similarities and differences between the two. This contour map is similar to a hypsometric map because it is showing information on a third dimension, the time it takes to travel by rail in England. This map uses both colors and contour lines to represent the third dimension. The author of this website calls these contour lines isochrones. The lines represent one hour of time. 

My Society 

Hypsometric Map

My Society  has a great website for looking at Hypsometric and Contour maps. For the entry in my map catalog I will focus on the Hypsometric properties of this map. The third dimension that is being communicated is the time it takes to get from Cambridge to outlying cities in England. Red is fastest with blue being the slowest. A pattern emerges with it taking less time to reach destinations within a tight circle and then taking longer as the distance from the center increases. A few exceptions seem to follow specific routes in an almost straight line radiating out from the center. These are probably major rail ways. 

Planimetric Map

This is a Planimetric map of my hometown, Pensacola Fl. The defining feature of a planimetric map is the lack of any representation of relief. Planimetric maps are usually street maps because knowing elevations aren't as important for getting around. This map was found at FloridaBrasil.com

Cartogram

University of Michigan

Cartograms are a sort of statistical thematic map. A geographer takes statistical data and then distorts the area of a map to represent the magnitude of the variable. For example, this map is a cartogram displaying information on green-house emissions. The larger the area the more green-emissions. It's easy to identify which regions are doing their part for the environment and which ones are not. 

Statistical Map

Britannica Online

This map is a classic example of a statistical map. As the map explains, each dot represents 10,000 acres of corn. It allows the reader to quickly and easily see a dense concentration around the midwest states. 

PLSS Map

National Atlas

The PLSS system is a systematic Cadastral map. Most of the United States uses this system to divide up land. Principle meridians perpendicular to base lines are the basis for this system. Every 6 miles in all 4 directions another line is drawn. Zones created by north-south lines are called townships and zones created by east-west lines are called ranges. This system is most common in the midwest and western part of the country that was not influenced by the colonial metes and bounds system. 

Cadastral Map

Website of Delaware County Auditor 

This is a cadastral map of Delaware County. Notice the ordered, systematic parceling out of land. This is also a very good example of  PLSS (public land survey system) Map. In PLSS maps the area is divided down to the tiny parcels of land that indicate ownership. 

Topographic Map of Malta

How Stuff Works

Topographic maps are useful in showing the various elevations of land. This is a map of Malta, a small country in the Mediterranean Sea. This map clearly informs the reader that this is a relatively level country with no mountains besides a few hilly regions. 

Thematic Maps

EPA Website

Thematic maps are used to represent the distribution of something. It could be things like people, money, trees, and animals, or it could be less physical things like education levels, pollution levels, or income levels. This map from EPA informs the reader of the "pounds released, number of chemicals involved, and the risk related results." 

Mental Maps

Legible London

Mental maps are our perceptions of the world around us. This map is an attempt to make an abstract mental map more concrete by asking an individual to draw out their mental map of London-the way they visualize the streets of London in their mind. 

Digital Map: Close to Home, a Bird's Eye View

View Larger Map

This is a remotely sensed map taken by satellite. Using the zoom features it is possible to see my house and backyard. 

I found this map on the Google Maps site.