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arXiv · 2502.02907

PoleStack: Robust Pole Estimation of Irregular Objects from Silhouette Stacking

Jacopo Villa·Jay W. McMahon·Issa A. D. Nesnas
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Abstract

We present an algorithm to estimate the rotation pole of a principal-axis rotator using silhouette images collected from multiple camera poses. First, a set of images is stacked to form a single silhouette-stack image, where the object's rotation introduces reflective symmetry about the imaged pole direction. We estimate this projected-pole direction by identifying maximum symmetry in the silhouette stack. To handle unknown center-of-mass image location, we apply the Discrete Fourier Transform to produce the silhouette-stack amplitude spectrum, achieving translation invariance and increased robustness to noise. Second, the 3D pole orientation is estimated by combining two or more projected-pole measurements collected from different camera orientations. We demonstrate degree-level pole estimation accuracy using low-resolution imagery, showing robustness to severe surface shadowing and centroid-based image-registration errors. The proposed approach could be suitable for pole estimation during both the approach phase toward a target object and while hovering.

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Jacopo Villa, Jay W. McMahon, Issa A. D. Nesnas. 2025-02-05. PoleStack: Robust Pole Estimation of Irregular Objects from Silhouette Stacking. https://arxiv.org/abs/2502.02907

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