2. Besides Being Tidy, What's a Neat Model?

The neat model for a overlapping photo pair is the area between their principle points in the flight direction and extends halfway into the sidelap areas, Figure E-5.

Figure E-5 Neat Model Definition

Figure E-6 shows the neat model dimensions on an overlapping photo pair:

• l is the negative/image size (e.g. 9 in by 9 in)
• EL is the endlap in percent
• SL is the sidelap in percent

Figure E-6 Neat Model Dimensions

For example, using a 9 in x 9 in negative format with 60% endlap and 30% sidelap, the neat model dimensions are:

9 in (1-0.6) = 3.6 in

9 in (1-0.3) = 5.4 in

The neat model is the primary area for making stereo measurements and perform mapping opeartions. The model doesn't reach all the way across the endlap and sidelap areas because the largest lens distortions typically occur along the photograph edges.

Because it's the mapping area, it's also used for flight planning purposes.