Visualizing Earth

By Katherine D.

Test 1 Form A

1. The universe is bathed in electromagnetic radiation. Understanding the messages that light carries has changed our understanding of our earth, solar system, and universe.

1. The Electromagnetic spectrum is made up of many forms of light. The electromagnetic spectrum gradually increases in frequency starting from left to right. The major parts of the electromagnetic spectrum are TV and radio waves, microwaves, U.V., I.R., visible, X-ray, and gamma rays. TV and radio waves help to transfer information, images, and sound throughout our universe. Microwave can be used to take a digital image. It is able to penetrate clouds and can use radar to take topographical images. U.V. can tell us about the radiation from the sun. I.R. can help us to track living things and see the changes that occur, visible light can tell us about the world we live in and the things we see everyday. X-ray can penetrate through our bodies to give us information about our bones, and gamma rays help us in space to learn about black holes.
2. The first activity we did in class was with a light spectrum tool. We took the light spectrum tool outside and pointed it towards the sky so we could see what white light looked like through a prism. When we looked at the white light we were able to see a continuous spectrum, which was all colors (ROYGBIV) in a continuous line. From this activity we learned that white light is made up of all the colors. Another activity we did concerning light was the polarized lenses activity. We learned how if you take a vertical polarized lenses it filters out everything but the vertical waves of light. Then if you turn the polarized lenses to a 90degree angle the lines on the polarized lenses will go horizontally, filtering out everything but the horizontal waves of light. So almost all the waves are being filtered out. This activity demonstrated to us how filters work with light.
3. New ways of seeing means now we are able to "see" our world with sources besides our physical eyes. We are able to use other parts of the electromagnetic spectrum besides visible light to learn information about our universe. See Question 1 part A to see how each part of the electromagnetic spectrum is being used. Microscopes have helped to revolutionize biology because we are now able to see what makes up a certain thing, we have been able to learn more about atoms and cells. Telescopes have revolutionized astronomy because we are able to see into our universe and look at different planets and stars. Satellites are the last tool, they helped Earth Science by being able to look at our world from higher ground. We've been able to monitor changes and predict more new changes.

2. Our understanding of planet Earth has changed dramatically since the 1950's because of satellites and remote sensing.

1. Remote Sensing is gathering data form a distance. Satellite images are used on earth in an infinite amount of ways. They are used to look at our world form a distance, to help stop natural disasters and famines, they are used in war to help find out information about the enemy and help to stop needless killing, and satellites are used to see how our world is ever-changing. Satellites transmit things to earth by scanning an image. They take the brightness values of each pixel f an image. From that they the brightness value numbers into a binary code. It is then sent to earth where it is received on a receiver (a big satellite dish.) The binary code is then given to a computer where it is stored , the computer then changes the binary code back to the brightness value where it is put on a PC image and true or false color can be added.
2. The first satellites were used in the Cold War to pick up telephone conversations of the Russians. Later they were used to detect if a missile was going to be launched. Now satellites are still being used in the military, but they have also become popular for civilians. Civilians use satellites thousands of ways now, they use them for cellular phones, TV's, computers, and GPS. Satellites are being used to predict weather, track vegetation growth, and to warn people about natural disasters before they hit.
3. Remote Sensing has helped to see the world from higher ground. It has shown us that everything a person or nation does affects everybody else and that what goes around comes around. Remote sensing has helped to save thousands of lives in Africa to help get food to areas that were experiencing famines. It has also helped to warn people in advance about weather, such as El Nino and Hurricane George to help save lives. Remote sensing has shown us the effects of pollution and other man made problems on the world and how we need to fix these problems.

3. The cliffs and beaches of the north county are a local treasure. Cliff erosion and loss of bluffs will result in a major loss of revenue from tourism, the construction of very expensive sea walls, the loss of homes and property, and an overall deterioration in our quality of life.

1. A digital image is an image made up of numbers, which represent the brightness value of each pixel. The values range from 0-255.
2. Visual light can be used in the study because it can show us how much dirt is being eroded gradually each year by a picture we see with our real eyes everyday. Infrared light can show us how vegetation is being affected by this and from that we can see how population has decreased or increased. Microwave sensing can be used to take a topographical picture of how much of the cliffs have decreased and how much higher the land below the cliffs has increased. It is also ideal for taking pictures along the coast because it can penetrate clouds and fog.
3. True color is the real color of the image that we see in everyday life. False color is color added to the image that is not the true color of the image but is used to enhance the picture to find out more information. True color images are made by Grey + Grey + Grey = Color. The first thing you do is scan an object with a special camera or satellite. The object goes through three filters, red , green, and blue. For each filter a gray scale value is taken for each pixel. You come up with three gray scale vales for the image. Then you take those three gray scale values, one for each filter and superimpose them to get one RGB value that matches with a color from the color wheel. There are over a million true colors.

False color is made when you take the brightness value for each pixel. You then transfer it to a computer where it can be made into a gray scale image, then you can assign any color to each pixel value.

D. Spectral Signatures can help to create false color images because for everything in the world there is a different percentage of reflectance depending on the bandwidths. On a spectral signature graph it shows the different contrasts in reflectance for each object. From the graph you would want to see at which bandwidths the object would be the brightest, or where there would be the greatest difference in brightness between two objects. From that you could decide which color could be added to get the most information out of the object.