FORMULA

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To lay out flight maps on 1"=2000' scale USGS Quadrangle maps.

If the forward overlap is 60% the side lap is 30%

 

Then, the forward gain = 40%. The side(gain) = 70%.

 

40% of a 9" negative= 3.6"      on negative 70% = 6.3" on negative

 

forward gain = photo scale x 3.6" line spacing=photo scale x 6.3"

                      map scale                                map scale

 

 

 

Example: @ 1" = 200' photo scale:

 

 

ON THE MAP

 

forward gain = 200 x 3.6" = .36" line gain = 200 x 6.3" = .63"

                         2000                                  2000

 

 

KEYSTONE AERIAL SURVEYS, INC.

 

Northeast Philadelphia Airport

P.O. Box 21059

Philadelphia, Pennsylvania  19114

 

(215) 677-3119 * (215) 464-2889 Fax