Tuesday, September 26, 2006
Here is Lab 3. It is my rendition of a Mollweide Graticule. A Mollweide projection is an equal area projection which makes it useful for comparing populations over areas.
I really enjoyed making this map, except for the problems I encountered with the software. I have heard that Adobe software is powerful, but that the learning curve is steep. I have to agree. I still have not figured out the trim tool, but I did figure out how to use the "Divide below" option, (Object/Path/Divide objects below) in order to trim off my parallels.
Thursday, September 21, 2006
Lab 3 is coming soon, but meanwhile I found an oblique Mollweide projection. I think it is so neat that both poles are visisble. This map was drawn by Hans Havlicek. I found it at Google Images and this is his website:
www.geometrie.tuwien.ac.at
Lab 2: Representations of the Earth.
First I drew the sphere, the sphere was the first round representation of the earth. Newton proved that the earth was an ellipsoid flattened at the poles.
This representation is still a pretty good way to visualize the earth. The flattening at the poles is only 1\298 which is pretty small. I tried to make my ellipsoid geometrically correct; my width was 432 points or six inches. Dividing 432 by 298 results in approximately 1.45 points. This difference is not enough to be seen when superimposed onto the sphere. So I exaggerated the ellipsoid so that the flattening would be apparent.
The geoid presented a different problem all together. It is supposed to represent how gravity acts on the earth if the entire earth's surface was mean sea level. This is useful for geodetic surveys when accuracy really counts. But I had no idea what it would look like. Below is the picture I found at Google Images which gave me an idea of what to draw. I was surprised at its shape, it looks like a child's ball of play-doh, but once I thought about it it made sense. The earth is not an homongeneous rock, it is a sludge in the center and so it should deform when strong forces act on it and it does, locally. So when we look at the earth it is still looks like a sphere, but when we do extremely accurate geodetic surveys for things like bridges we have to take into account the changes that occur because of gravity at the local level. When I drew the geoid I was not sure about what size it should be so I made it about the size of the ellipsoid.
The natural surface I stylized to represent rocky and smooth surfaces laid on top of the ellipsoid.
First I drew the sphere, the sphere was the first round representation of the earth. Newton proved that the earth was an ellipsoid flattened at the poles.
This representation is still a pretty good way to visualize the earth. The flattening at the poles is only 1\298 which is pretty small. I tried to make my ellipsoid geometrically correct; my width was 432 points or six inches. Dividing 432 by 298 results in approximately 1.45 points. This difference is not enough to be seen when superimposed onto the sphere. So I exaggerated the ellipsoid so that the flattening would be apparent.
The geoid presented a different problem all together. It is supposed to represent how gravity acts on the earth if the entire earth's surface was mean sea level. This is useful for geodetic surveys when accuracy really counts. But I had no idea what it would look like. Below is the picture I found at Google Images which gave me an idea of what to draw. I was surprised at its shape, it looks like a child's ball of play-doh, but once I thought about it it made sense. The earth is not an homongeneous rock, it is a sludge in the center and so it should deform when strong forces act on it and it does, locally. So when we look at the earth it is still looks like a sphere, but when we do extremely accurate geodetic surveys for things like bridges we have to take into account the changes that occur because of gravity at the local level. When I drew the geoid I was not sure about what size it should be so I made it about the size of the ellipsoid.
The natural surface I stylized to represent rocky and smooth surfaces laid on top of the ellipsoid.
Monday, September 18, 2006
Monday, September 11, 2006
The Geography of Virginia class was one of the most informative and interesting Geography classes I have taken so far at George Mason. Any one interested in Virginia may search most of its contents so I have added the link to Virginia Places. The following links were websites that I used frequently in that class.
The USGS_GNIS is useful tool for searching for Geographic place names in the United States. For example, if you forgot the height of the highest point in Virginia, but you remembered it's name, Mount Rogers, you can look it up at this site. It will tell you where it is located as well as its height.
Virginia Watersheds is exactly what it says. It identifies the different watersheds in Virginia. This makes is easy to tell where that run off from your driveway winds up. For us the water winds up in the Atantic Ocean, but there is a section in the western part of the state where the water eventually ends up in the Gulf of Mexico.
The USGS_GNIS is useful tool for searching for Geographic place names in the United States. For example, if you forgot the height of the highest point in Virginia, but you remembered it's name, Mount Rogers, you can look it up at this site. It will tell you where it is located as well as its height.
Virginia Watersheds is exactly what it says. It identifies the different watersheds in Virginia. This makes is easy to tell where that run off from your driveway winds up. For us the water winds up in the Atantic Ocean, but there is a section in the western part of the state where the water eventually ends up in the Gulf of Mexico.
Saturday, September 09, 2006
I have never blogged before so this is a new experience for me, but I am always up for a new adventure so here we go...
This picture was taken outside of the window where I do my homework. I have a lighthouse-shaped hummingbird feeder; while I was working on this assignment a bird perched on the wire hanger of the feeder. I thought it was too good to pass up and so here it is.
