We present a new approach to combine remote observations and in situ data by
STEREO/HI and Wind, respectively, to derive the kinematics and propagation
directions of interplanetary coronal mass ejections (ICMEs). We used two
methods, Fixed-Phi and Harmonic Mean, to convert ICME elongations into
distance, and constrained the ICME direction such that the ICME distance-time
and velocity-time profiles are most consistent with in situ measurements of the
arrival time and velocity. The derived velocity-time functions from the Sun to
1 AU for the three events under study (1-6 June 2008, 13-18 February 2009, 3-5
April 2010) do not show strong differences for the two extreme geometrical
assumptions of a wide ICME with a circular front (Harmonic Mean) or an ICME of
small spatial extent in the ecliptic (Fixed-Phi). Due to the geometrical
assumptions, Harmonic Mean delivers the propagation direction further away from
the observing spacecraft with a mean difference of ~25 degree.
