Mmm I see…
Indeed I thought that the master image will keep the master image name + _Orb_Split.dim or _split_Orb.dim or similar that SNAP adds at the end.
Could you please keep the master splitted name similar to:
S1A_IW_SLC__1DSV_20171208THHMMSS_20171208THHMMSS_YYYY_XXXX_ZZZZ_split_Orb.dim
My script in fact takes 8 characters starting from 19th character in the master string’s name. It might seem a bit weird that decision, but it seem to be quite logical and intuitive to get the master acquisition time for the master name after splitting and apply orbit step, assuming you do so using SNAP, and hence following its naming convention. Next time I will just get it from the metadata itself, whatever name the master may have. 