  We consider three-dimensional (3D) localization and imaging of space debris
from only one two-dimensional (2D) snapshot image. The technique involves an
optical imager that exploits off-center image rotation to encode both the
lateral and depth coordinates of point sources, with the latter being encoded
in the angle of rotation of the PSF. We formulate 3D localization into a
large-scale sparse 3D inverse problem in the discretized form. A recently
developed penalty called continuous exact l0 (CEL0) is applied in this problem
for the Gaussian noise model. Numerical experiments and comparisons illustrate
the efficiency of the algorithm.
