WETMAAP Skill 2
Weedon Island - Element 2
Materials:
1:24,000 scale 1998 Safety Harbor/Gandy Bridge/ Saint Petersburg, FL; 1956/81 Port Tampa, FL,USGS Topographic Quadrangle
2002 Aerial Photography of study site
9" x 9" clear film overlay
color permanent marking pens
ultra fine black permanent marking pen
ruler
drafting tape
calculator
Reference Manual
Exercise:
1. Tape the 9" x 9" clear film overlay on top of the 2002 aerial photography.
2. Use the Black pen to make four marks on each fiducial.
Hint: The fiducial is a yellow dot or cross-hair along each of the four sides of the aerial photography.
3. Using the 1:24,000 scale topographic map and the Black pen, locate the four corners of the study site on the 2002 aerial photography.
4. Use the ruler and the Black pen; link the four corners of the study site to make a complete boundary.
5. Identify two points on the 1:24,000 scale topographic map at least four inches apart.
Hint: It is best to identify and use cultural features, but if not enough are available, use two natural feature points that do not appear to have changed.
6. Identify the exact same two features from the topographic map on the 2002 aerial photograph. Make a mark on the aerial photograph for each location.
7. Measure the distance between the two points on the 1:24,000 scale topographic map with the ruler.
________What is the distance in inches?
8. Measure the distance between the two points on the 2002 aerial photograph with the ruler.
________What is the distance in inches?
9. Using the calculator and "Scale Determination" section of the Reference Manual, determine the scale of the aerial photograph.
________What is the scale that you calculated?