Characteristics and Examples of Spatial Data - Introducing Geographic Information Systems with ArcGIS - page 141

12. Right-click the yellow rectangular symbol (7) in the T/C, and click More Colors to open the Color
Selector window. Notice that the Red, Green, and Blue (RGB) values are approximately 254,
234, and 0. Move the slider on the Green bar (G) back to 0. Note the resulting color in the
lower-left corner of the Color Selector window: pure Red. Click OK to change the yellow color
symbol to that color. This change is also reflected in the number 4 symbol in the T/C as well as
on the map. Experiment by setting several symbols to different colors. To see the pure primary
color Green, set the Green color bar to 255 and the other two to 0. Do the same for the other
primary colors. Notice also that the intensity of the resulting color (shown at the lower left of
the Color Selector window) is controlled by the sliders. Click OK and note the change in the
DRG. Change the white pixels to black and the black pixels to white.
13. When you have finished experimenting, remove COLE_DRG.TIF from the map. This nullifies any
changes you have made to the color symbols. Add COLE_DRG.TIF back to the map; expand its
legend to verify that you haven't done any permanent damage to the default color scheme.
14. You don't really want every color symbol cluttering up your T/C, so collapse the dataset legend
if it is showing. Initiate a zoom out with the Fixed Zoom Out button on the Tools toolbar, and
click it repeatedly. Observe how visually meaningless pixels combine to form an image.
Experimenting with Different Ways of Seeing Data
15. Zoom to the GPS track using the bookmark you made previously. Click the Windows menu and
click Magnifier. When the Magnifier window appears, drag it, by its title bar, so that the cross
hairs are centered over the Normal Pool Elevation number and verify its value in the magnified
view. _____________. Then, drag the window over the island and compare the COLE_VCTR
lines with the elevation lines depicted by the topographic map. Notice that you can resize
the Magnifier window by dragging its sides and corners; also you can change the level of
magnification with a drop-down menu. Right-click the title bar of the Magnifier window and click
Viewer to lock the view, so you can move the Magnifier window—now Viewer window—and
not change its contents. Open another Magnifier window and check out its menu options by
clicking the little right-pointing triangle and selecting properties from the resulting drop-down
menu. Note the current properties and then experiment with them (you may have to move the
properties windows if it has appeared directly on top of the magnifier window) before returning
them to the original settings and dismissing the properties window. Notice that you can “see
through” the Viewer window with the Magnifier window. See Figure 2-24. Dismiss the Viewer
window and the Magnifier window.
16. Zoom to Boat_SP83. Select Windows > Overview. In the Layers Overview window, right-click the
title bar and click Properties. In the Overview Properties window, find the Reference Layer text
box and, if COLE_DRG.TIF is not selected, pull down the menu and click COLE_DRG.TIF. Now
click Apply, then OK. Resize and drag the Layers Overview window so that it fits comfortably in
the lower left of your screen. See Figure 2-25. The Data Frame window shows the GPS track,
part of the DRG, and other data. The Layers Overview window shows the entire DRG. Within that
window is a box (gray with a red outline) that indicates whatever is displayed in the data frame.
17. Dragging the outlined box in the Layers Overview allows you to pan around the COLE_DRG.TIF
layer. Move it over to the city of Lexington. Then move it back to the river bend. Also, if you use
the Zoom controls or the Pan control on the map in the data frame, the new view is reflected by
changes in the size and location of the outline box in the Layers Overview window. Use Zoom