Image Preprocessing : Spatial & Spectral Enhancements and Band Indices(Module 4)

 Image Preprocessing : Spatial & Spectral Enhancements and Band Indices

Lab Assignment:

1. Examine the histogram for shapes and patterns in the data.
2. Visually examine the image as grayscale for light or dark shapes and patterns.
3. Visually examine the image as multispectral, changing the band combinations to make certain features stand out. 
4. Use the Inquire Cursor to find the exact brightness value of a particular area.

After completing these four steps I settled on using False Natural color for all of my layouts because it represented all the features well. 

Q: In Layer_4 there is a spike between pixel values of 12 and 18. Name the type of feature responsible for this and locate an example of it on the map.

A: Water. Using TM False natural color I identified this feature as water. This choice of bands made water highly visible with high contrast between the waters edge and land. Using this configuration also allowed me to make distinctions within water as well.

Q: Identify the feature that represents both A) a small spike in layers 1-4 around pixel value 200, and B) a large spike between pixel values 9 and 11 in Layer_5 and Layer_6. 

A: Snow/Ice Using TM False natural color I identified this feature as snow and/or ice. This choice of bands made these areas highly visible while also providing more details than in the default configuration where the snow/ice areas were large and white with little to no distinction within.

Q: In certain areas of water, layers 1-3 to become much brighter than normal, layer 4 becomes somewhat brighter, and layers 5-6 to remain unchanged. Locate an example area that clearly shows these variations in water, using a band combination that makes them stand out.

A: Water Variation. Using TM False natural color I identified variation in the water at the mouth of this river. This choice of bands made water highly visible with high contrast between the waters edge and land. Using this configuration also allowed me to make distinctions within water as well. I am unsure if this is a difference in depth, turbulence, or silt content. The location could indicate a change in depths, but the fan shape makes me think this could be sediment from the river running into the larger body of water.