Aerial Triangulation & Bundle Adjustment Flashcards

What is the collinearity condition in photogrammetry?

Answer: The object point, perspective center, and image point all lie on a straight line

The collinearity condition states that the object point, the camera's perspective center, and the corresponding image point are collinear—forming the mathematical basis for photogrammetric equations.

In AT processing, what is a 'pass point'?

Answer: A point measured in consecutive photos along a flight strip to pass geometry forward

A pass point is measured in consecutive overlapping photographs along a strip to propagate (pass) the geometry from one model to the next.

What is the effect of using too few ground control points in a large photo block?

Answer: Systematic deformations and poor absolute accuracy of the final product

Insufficient ground control allows systematic block deformations to go uncorrected, degrading the absolute accuracy of the final mapping products.

Which accuracy metric is used to evaluate ground control point residuals after bundle adjustment?

Answer: RMSE (Root Mean Square Error)

RMSE is the standard metric for evaluating GCP residuals after bundle adjustment, summarizing the overall positional accuracy of the solution.

What is a 'degenerate network' in aerial triangulation?

Answer: A network where all control points are collinear or poorly distributed, making the solution unstable

A degenerate network occurs when control points are poorly distributed (e.g., all collinear), creating rank-deficient normal equations and an unstable or non-unique solution.

Airborne GPS/IMU data integrated into bundle adjustment primarily improves which aspect?

Answer: Reduction in the number of required ground control points

Integrating airborne GPS/IMU (direct georeferencing) data into bundle adjustment drastically reduces the number of ground control points needed while maintaining accuracy.