Inversion solutions of the elliptic cone model for disk 3 frontside full halo coronal mass ejections

6 [1] A new algorithm is developed for inverting six unknown elliptic cone model 7 parameters from five observed CME halo parameters. It is shown that the halo parameter 8 a includes the information on the coronal mass ejection (CME) propagation direction 9 denoted by two model parameters. On the basis of the given halo parameter a, two 10 approaches are presented to find out the CME propagation direction. The two-point 11 approach uses two values of a observed simultaneously by COR1 and COR2 on board 12 STEREO A and B. The one-point approach combines the value of a with such 13 simultaneous observation as the location of CME-associated flare, which includes the 14 information associated with CME propagation direction. Model validation experiments 15 show that the CME propagation direction can be accurately determined using the two16 point approach, and the other four model parameters can also be well inverted, 17 especially when the projection angle is greater than 60 . The propagation direction and 18 other four model parameters obtained using the one-point approach for six disk frontside 19 full halo CMEs appear to be acceptable, though the final conclusion on its validation 20 should be made after STEREO data are available.