Lab 8 Answer Sheet

Multi-band (Spectral) Enhancements

Name 1 Name 2

1. In what kind of areas are the clay features highlighted (urban, rural forest, agricultural)? Why is this? You can link the two viewers if you are having trouble comparing sites on the two images.

2. Where do the highest concentrations of ferrous and iron oxides occur? Why do clays not occur in these areas instead?

3. What is the size in kbytes of your 2 images? Why is the new image so much larger than the original tmAtlanta image?

4. Go to the green patch at the x,y location of 140,-175 (you can use the inquire cursor to locate this position). In terms of mineral composition, what does this area represent?

5. At 380, -351 there is a bright yellow patch near a road. Immediately adjacent to it are areas that are much darker orange near 382, -346. The adjacent road surface is black. What do these colors represent in terms of mineral composition?

6. If you were concerned wit non-point source pollution in the form of sediment, how might you use the results of your mineral composite image?

7. How accurate do you think these results might be? What could you do to evaluate the accuracy?

8. What features are highlighted (i.e., are the brightest) in layers 1, 2 and 3 of the tasseled cap transformation?

Layer 1:

.

Layer 2:

Layer 3:.

9. Which image does the best job of separating trees from tree shadow?

10. What features, if any, shown up more clearly on the tasseled cap image? Are there features which are confused (e.g., different features showing up as the same color) on the tasseled cap image?

11. Can you detect differences in how these two images highlight vegetation? What about other features shown on the image?

12. In very general terms, describe how the plots differ between the TM5 image and the hyperspectral image.

13. Why does the hyperspectral image show such low reflectances in layers 8,12, 16 an21?

14. Open layer 1 of the hyperspectral image as a gray scale image. Why does this image show so little variations across the landscape?

15. Which layers appear to best distinguish between big categories of land cover (vegetation, water, wood, gravel, etc.)? Alternatively, at what point in terms of layer number do the images become noisy and make it difficult to distinguish categories of land cover)?

16. Focus on the variations within the stream. Do layers 1 and 2, or do layers 3 through 5 seem to depict more of the in-stream variations? Combined with your answer to question 15, what does this indicate about the types of information depicted in different pc layers as the pc number grows higher?

17. What is the size of your Lamar_TM5_pc image?

18. Compare layer 1 of the Lamar_hyper_pc image to layer 1 of the Lamar_tasseled_cap image. You will note that they are very similar. Why do you think this is the case?

19. How do the two images vary? Specifically, which one provides more information and detail.

20. State the layers you chose and the enhancements you applied to create an image that maximized in-stream variations.