Scaling and Photogrammetry

Homework Content

Equations and Assumptions

Assume the focal length ‘f’ to be 6 inches or 152 millimeters.

Scaling Relationships

$$\begin{split}\frac{d}{D} &= \frac{1}{\textrm {scale factor}} = \frac{f}{H}\end{split}$$ $$\begin{split}d &= \textrm {map distance} \\ D &= \textrm {ground distance} \\ f &= \textrm {camera focal length} \\ H &= \textrm {flying height} \\\end{split}$$

Problems

Show all your work clearly with all units and in detail, leading up to the answer:

1. An air photo has a scale of 1:50000.

If a given map length is two inches, what is the corresponding ground distance in:

1. inches
2. feet
3. meters

What is the flying height of the airplane in:

4. feet
5. meters

If a building has map length of two inches and map width of three inches, what is the ground (actual) area of the building in:

6. square inches
7. square feet
8. acres

2. Repeat problem one if the scale of the air photo is 1:82000.

Metadata

Title:Scaling and Photogrammetry

CreationDate:06/20/2013

SoftwareUsed:None

SoftwareVersion:None