... Image motion directions: calculation of the parallactic angle . Which actuator motions could be responsible for the observed image jumps? ... I report here on the analysis of these data and what it tells us about the causes of the image motion jumps. ... The calculations for the effects of secondary actuator motions on image jumps are similar to those shown for the primary. ... As was seen in Figure 9 , this axis could not explain the motions seen in the Feb. 8 image jump. ...