@marjanmarbouti
@ABraun
My master thesis is about atmospheric correction, it can be accessed here:
http://www.dongiatti.com/wp-content/uploads/2016/10/Ph_Ott_Masters_Thesis_GEO511.pdf
I asked myself the same exact question and I managed to do an atmospheric correction based on ECMWF weather data. I processed the S1A data with SNAP and did a DEM based interpolation of the atmospheric values. At the end I corrected the relative unwrapped phase values with the measured path delay.
Have a look
Kind regards
Philippe