Exercise 1

Question 1

Consider the following data:
Study Area: 20km E-W & 35 km N-S
Elevation: 500m Above Sea Level
Desired Photo Scale: 1:25000
Film Format: 23x23cm or 0.23x0.23m
Focal Length: 152mm or 0.152m
Overlap: 60%, Sidelap: 30%

Determine Flight Altitude H’

Answer 1

From RF=f/H or H=RFd*f, H=3800+500=4300m

Question 2

Consider the following data:
Study Area: 20km E-W & 35 km N-S
Elevation: 500m Above Sea Level
Desired Photo Scale: 1:25000
Film Format: 23x23cm or 0.23x0.23m
Focal Length: 152mm or 0.152m
Overlap: 60%, Sidelap: 30%

Determine the Ground Distance coverage of a single photo.

Answer 2

Recall RF=PD/GD or GD=RFdPD; Here GD=250000.23m=5750m

Question 3

Consider the following data:
Study Area: 20km E-W & 35 km N-S
Elevation: 500m Above Sea Level
Desired Photo Scale: 1:25000
Film Format: 23x23cm or 0.23x0.23m
Focal Length: 152mm or 0.152m
Overlap: 60%, Sidelap: 30%

Find the number of flight lines, NL

Answer 3

NL=[W/(GD)(Sg)]+2; where W=Width of study area, GD=ground distance of a single photo and Sg=Sidelap gain (100-sidelap) and 2=extra flight lines (1 per side). Now NL=[20km/(5.75km)(0.7)]+2=7 (round up)

Question 4

Consider the following data:
Study Area: 20km E-W & 35 km N-S
Elevation: 500m Above Sea Level
Desired Photo Scale: 1:25000
Film Format: 23x23cm or 0.23x0.23m
Focal Length: 152mm or 0.152m
Overlap: 60%, Sidelap: 30%

Determine the number of photos per Flight Line, NP

Answer 4

NP=[L/(GD)(Og)]+4 where L=Length of flight line, GD=Ground distance of single photo, Og=overlap gain (100-%overlap), and 4=extra photos (2 per end of flight line). Thus NP=[35km/(5.75km)(0.4)]+4=15.2+4=19.2=20

Question 5

Consider the following data:
Study Area: 20km E-W & 35 km N-S
Elevation: 500m Above Sea Level
Desired Photo Scale: 1:25000
Film Format: 23x23cm or 0.23x0.23m
Focal Length: 152mm or 0.152m
Overlap: 60%, Sidelap: 30%

Find the number of photons TN

Answer 5

TN=number of flight linesxphotons per flight line=NPxNL