Camera rotations in aerial photography – name the rotation about the vertical (optical) axis During exposure, when the camera undergoes a rotation about its vertical axis (through the perspective center), what is this motion commonly called in photogrammetry?

Introduction / Context:
Orientation of aerial photographs is described using small rotations about three mutually perpendicular axes. Correctly naming these rotations is essential for understanding exterior orientation, image rectification, and error sources in photogrammetry.

Given Data / Assumptions:

• Axes follow photogrammetric convention: two horizontal axes in the image plane and a vertical axis through the perspective center.
• We consider instantaneous camera attitude at the moment of exposure.
• Terminology aligns with classical stereoplotter usage (ω, φ, κ or equivalents).

Concept / Approach:
The three basic rotations are often denoted ω (about x), φ (about y), and κ (about z, the vertical axis). Traditional names are tilt and tip for rotations about horizontal axes, and swing for rotation about the vertical (optical) axis. Swing effectively rotates the image around its nadir/principal point in plan.

Step-by-Step Solution:
Identify the axis: vertical through the optical center → z-axis.Photogrammetric name for rotation about z-axis → swing (κ).Therefore, select “Swing”.

Verification / Alternative check:
Stereoplotter controls typically label κ as the swing knob, changing the image's azimuthal orientation without altering tilt magnitude.

Why Other Options Are Wrong:

• Tilt and tip refer to rotations about horizontal axes, affecting apparent photo tilt.
• “None” is incorrect because a standard term exists.

Common Pitfalls:
Confusing aircraft yaw with camera swing; while related, photogrammetric naming is determined at the camera perspective center.

Final Answer:
Swing