functions the first peak as shown in fig1 g represents the resonant response of the vcm the error function transfer function es with the fundamental frequency of vcm 40 hz as the plot in fig1 h shows without any additional filtering or redesign of the vcm the error function does not have enough rejection for the jitter frequencies of 1 to 18 hz all the values are below 40 db in a first case as shown in fig1 i a 2 nd order peak filter is added at fpk 10 hz as is seen in the table of fig1 j only at 10 hz are there rejections better than 40 db in a second case as is shown in fig1 k 2 peak filters are added fpk 1 11 hz fpk 2 13 hz these results as shown in the table of fig1 l are better but 2 peak filters per axis add to the complexity of the hardware and can cause settling delays and stability problems in a third case as shown in fig1 m natural resonance frequency of the vcm is moved to 15 hz plus one peak filter at 10 hz as is seen in the table of fig1 n all.