Homologous points in photogrammetry — identifying corresponding pairs Which of the following pairs are homologous points (i.e., correspond to the same object point in the ground–image relationship)?

Introduction / Context:
In photogrammetry, a “homologous” pair comprises an image-space point and its corresponding point defined in object space (ground) under the imaging geometry. Recognizing homologous feature pairs supports orientation, calibration, and quality control of aerial photographs.

Given Data / Assumptions:

• Standard definitions of principal point, isocentre, and plumb (nadir) point.
• Well-defined camera geometry and ground reference framework.

Concept / Approach:
The photo principal point corresponds to the ground principal point; likewise, the photo isocentre corresponds to its ground counterpart; and the photo plumb point corresponds to the ground plumb point. Each pair refers to the same conceptual entity in image and ground spaces and is therefore homologous.

Step-by-Step Solution:

Verification / Alternative check:
Orientation procedures treat these control points as conjugate entities when transforming between image and object spaces, confirming their homologous nature.

Why Other Options Are Wrong:

• Rejecting any single pair would contradict standard photogrammetric definitions.

Common Pitfalls:
Confusing homologous points with conjugate image points between left and right photos; here, the pairing is between photo and ground, not between two photos.

Final Answer:
All of the above