The Solar TErrestrial RElations Observatory ( STEREO ) and its heliospheric imagers ( HI ) have provided us the possibility to enhance our understanding of the interplanetary propagation of coronal mass ejections ( CMEs ) .
HI-based methods are able to forecast arrival times and speeds at any target and use the advantage of tracing a CME ’ s path of propagation up to 1 AU .
In our study we use the ELEvoHI model for CME arrival prediction together with an ensemble approach to derive uncertainties in the modeled arrival time and impact speed .
The CME from 3 November 2010 is analyzed by performing 339 model runs that are compared to in situ measurements from lined-up spacecraft MESSENGER and STEREO-B .
Remote data from STEREO-B showed the CME as halo event which is comparable to an HI observer situated at L1 and observing an Earth-directed CME .
A promising and easy approach is found by using the frequency distributions of four ELEvoHI output parameters , drag parameter , background solar wind speed , initial distance and speed .
In this case study , the most frequent values of these outputs lead to the predictions with the smallest errors .
Restricting the ensemble to those runs , we are able to reduce the mean absolute arrival time error from 3.5 \pm 2.6 h to 1.6 \pm 1.1 h at 1 AU .
Our study suggests that L1 may provide a sufficient vantage point for an Earth-directed CME , when observed by HI , and that ensemble modeling could be a feasible approach to use ELEvoHI operationally .