Three-dimensional reconstruction of coronal mass ejections using heliospheric imager data

Innovative techniques have been developed to extract three-dimensional (3-D) information on coronal mass ejections. Some techniques have only been available since the launch of the STEREO spacecraft, where geometry can be applied to white light observations from three different viewpoints. Another technique not necessarily requiring the multiple-viewpoint capabilities of STEREO involves heliospheric imaging. With heliospheric imagers, we may take advantage of the breakdown in geometrical and Thomson scattering linearity and, with careful analysis of the data, extract 3-D parameters from CME images. In this review we discuss the various techniques that are being developed and used to reconstruct the 3-D structure and kinematic evolution of CMEs, with a particular emphasis on the work of the author and colleagues. Following a brief review of multiple-viewpoint coronagraph analysis, we focus on techniques involving heliospheric images, which can be used to achieve the reconstruction with a good degree of accuracy without the need for auxiliary data.