Actually this work started around two months ago. At the beginging, we tried to fit the original data by using poles, zeros and q. At that time, we tried to use the virgo toolbox based on matlab and got some fine results. We also tried to use LISO to do this fit.
However, for our filter design for GRMC, it is not so necessary. So I use the data we took and change it back to imaginary number and then implent zpk filters to it. Finally, by using a first order low pass filter with a coner frequency of 500Hz. And a intergrator of 30Hz(pole) and 1000Hz(zero). And the gain of 2. I got a positive result wihch is shown as attached file. I also attach the python file as attached.