Lab 5

Highlighting features of interest on an image

through use of band combinations, colors, AOIs, and DEMs

Geog 418/518, Fundamentals of Remote Sensing

Name 1                                                       Name 2                                            

1.  Create the colors listed below, then fill in the table with the numerical values showing what proportion of each primary color is needed to create that color.

2.      In your own words, explain what it is that the intensity, hue and saturation refer to.

3.      From the perspective of a user trying to identify areas covered by different types of soil, what is a problem with this map and how might you fix it?

4.      How might use of one or more of these tools help to to visually interpret the image layers and their relationship? 

Part 2.  Altering band combinations to highlight key features

5.      How well can you distinguish variations within the forest with the 3,2,1 band combination?  From the perspective of scattering, reflectance, and/or absorption, why is this the case?

6.      Based on your answer to 5 above and your knowledge of reflectance/scattering/ and absorption, what might you do in terms of band selection to enhance your ability to see (to visualize) differences within the forest?  Explain your reasoning for your answer.

7.      How well can you distinguish the boundary between the lake and surrounding forest on this image?   In terms of scattering, reflectance, and/or absorption, why is this the case?

8.      Based on your answer to 7 above and your knowledge of reflectance/scattering/ and absorption, what might you do in terms of band selection to enhance your ability to delineate (to visualize) the lake/forest boundary?  Explain the reasoning for your answer.

9.      Would you use band 6 to delineate water from vegetation?  Why or why not?

10.   What value for the Euclidean spectral distance is best at outlining the lake while also avoiding having “holes” in the middle of the lake?

11.  How does the AOI change?

12.  What minimum value of  Euclidean distance outlines all the lake (including bridges) without including other features?  Provide the number. 

13.  Do you believe your lake AOI or your urban/forest AOIs did a better job of outlining the specific feature you were interested in?  Why do you think the spectrally based AOI was better in one environment than another?

14.  Do you believe the spectrally-based or the hand-drawn AOI was better for delineating the lake?  Why is this the case?

15.  In what circumstances might you use a spectrally defined AOI?  In what circumstances might a hand drawn AOI be the better option?

Part 4.  3-D displays

16.        As you look from SW (the left bottom of the image) to the NE, which sun angle works best for visualizing the landscape? Why is this?