Effects and compensation of phase drift in a 3D tower-turntable ISAR imaging system

Abstract

In view of 3D-ISAR measurements in near future, this paper studies the effects of peculiarities of the experimental measurement system and measurement geometry on the 3D polar-format imaging by simulation of ideal point scatterers. Particular a phase drift, an offset of the elevation rotation centre and near range distortion have to be compensated. Furthermore, a 3D-imaging of a sparsely sampled aperture is introduced. The presented investigations show, that 3D-ISAR imaging with an experimental system will be feasable despite of peculiarities like phase drift, different rotation centers in azimuth and elevation and near range distortion. Precondition is the phase exploitation of a reference corner located off the turntable, and precise knowledge of the measurement geometry. 3D-imaging with a sparsely sampled 3D-aperture indicated, that there is some potential of multi-platform sensing for ATR purposes that exceeds what can be achieved by just exploiting the single 2D information of each sensor. Therefore the oncoming measurement campaign and future studies shall give answers.