Hi guys,
Sorry for the silence here!
In general, you can try a way suggested by Tatiana here:
However, I can’t help but ask, why do you need to merge several UBX files? Do you need it to post-process all of them at once?
I’d also want to add that manual merging of the files may lead to mistakes: from simple typos to rejections of processing the file in software because of non-permanent intervals between epochs.