Comparison of running-difference images (rows a, c, e) of the three events with the results of applying the fitting technique (rows b, d, f) developed in Rouillard et al. (2016). The images are from the SDO AIA and the STEREO EUVI instruments (rows a and c) and from the STEREO-LASCO C2 instrument (row e). Red crosses superimposed on the fitted ellipsoids show the measured contours of the propagating fronts observed in the running difference images and are used to constrain the extent and location of the fitted ellipsoids at each time.