Geometric Errors in Satellite Imaging – Which one is random? Among common geometric error sources in satellite images, identify the error that is inherently random rather than systematic.

Introduction / Context:
Geometric errors in satellite imagery arise from sensor design, platform motion, and Earth geometry. Some are predictable and modeled deterministically, while others vary unpredictably and must be estimated from ancillary data or controlled via stabilization systems.

Given Data / Assumptions:

• Across-track scanning or pushbroom imaging in low Earth orbit.
• Nominal ephemeris and attitude data are available.
• We distinguish systematic versus random behaviour.

Concept / Approach:

Scan skew, panoramic distortion, and Earth rotation effects are systematic and repeatable given the same geometry and timing; they are corrected with known models. Altitude variations caused by atmospheric drag, gravity anomalies, or control jitter introduce non-repeating, random-like deviations in ground projection that require precise orbit determination and possibly ground control points to correct.

Step-by-Step Solution:

Verification / Alternative check:

Operational orthorectification workflows treat the first three with fixed models and consume precise ephemeris/attitude to mitigate random altitude/attitude noise.

Why Other Options Are Wrong:

They are primarily deterministic functions of scan geometry and timing and thus not random in the sense used in sensor modeling.

Common Pitfalls:

Confusing repeatable geometric distortions with stochastic platform perturbations; assuming ephemeris alone removes all random components without ground control.

Final Answer:

Altitude variation (platform height fluctuations)