Spatial Enhancement, Multispectral Data, and Band Indices Lab 4

 This lab focused on spatial enhancements which is a preprocessing step in preparing imagery for use. Enhancements modify data and imagery to help users interpret the data beyond what is initially apparent by using a variety of methods. This lab also focused on how to view properties of multispectral data and create band indices. 

ArcGIS and ERDAS Imagine were used in this lab to examine an image of the surrounding areas of the Olympic Mountains in Washington State. Most tasks required to complete this lab can be done in either program however using both made the lab faster and was able to have more thorough information. Descriptions of three features were given and the task was to identify that feature within the given image by examining the histogram, examining the image as grayscale, examining the image as multispectral, and using the inquire cursor to find brightness value. As well as use a different band combination for each map.

The first feature to identify was: 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. The feature identified was bodies of water that had a brightness of 14. By using False Color IR the water bodies were able to be clearly visible from the surrounding land.

The second feature to identify was: 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. The feature identified were glaciers on Mt. Olympus with a brightness of 10 in layers 5 and 6, and a brightness range of 193-200 in layers 1 through 4. TM False Natural Color was used to distinguish the glaciers from the surrounding mountain range.

The third feature to identify was: 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. The water area chosen was the Nisqualiy Reach, Tolten Inlet, and Budd Inlet area which showed the most variation in the water using TM True Color.