WETMAAP Skill 2
Golden Meadow - Element 2
Skill
2: Scale Determination
Element 14: Determining Scale of 1995 Aerial Photograph
1994 1:24,000 scale Golden Meadow/Golden Meadow Farms/Bay Courant/Mink
1995 Aerial Photograph of study site
9" x 9" clear film overlay
color marker pens
ultra fine black marker pen
ruler
drafting tape
calculator
Exercise:
1. Tape the 9" x 9" clear film overlay on top of the 1995 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 1995 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
1995 aerial photograph. Make a mark on the
aerial photograph for each location.
_________________
What is the distance in inches?
8.
Measure the distance between the two points on the 1995 aerial
photograph with the ruler.
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?