  Airborne optical sectioning, an effective aerial synthetic aperture imaging
technique for revealing artifacts occluded by forests, requires precise
measurements of drone poses. In this article we present a new approach for
reducing pose estimation errors beyond the possibilities of conventional
Perspective-n-Point solutions by considering the underlying optimization as a
focusing problem. We present an efficient image integration technique, which
also reduces the parameter search space to achieve realistic processing times,
and improves the quality of resulting synthetic integral images.
