Preliminary comparisons between the LASCO/C2-C3 and STEREO-COR2 A and B coronagraph images

Fabien Saez
(Laboratoire d\'Astrophysique de Marseille)

Lamy, Philippe
(Laboratoire d\'Astrophysique de Marseille)

Llebaria, Antoine
(Laboratoire d\'Astrophysique de Marseille)

Boursier, Yannick
(Laboratoire d\'Astrophysique de Marseille)

Ernandes, Fabrice
(Laboratoire d\'Astrophysique de Marseille)

Abstract
We present a study which qualitatively and quantitatively compares the performances of the SECCHI-COR2 A and B coronagraphs and the LASCO-C2 and C3 coronagraphs. We find that the instrumental straylight backgrounds in COR2 A and B is quite large. They are first removed from the the calibrated images using a method which determines the temporal minimum from a set of all polarized images, and compared to the background extracted from the LASCO-C2 and C3 images using the polarimetric method. Finally we compare the coronal images obtained from the four coronagraphs and discuss the prospects of the 3D reconstruction of CMEs.