I’ve already cracked how to get the gpt batch process working, through running bash script, as I have already written bash script for the preprocessing stages (Applying Orbital Files through the calibration and subsetting the products). Getting the gpt working isn’t the issue.
My main issue was regarding if variables could be defined within the expression part of band maths (the same way in which the file names are defined in the processDataset.bash file). Having done some more digging on the forums, I’ve come across what I believe is the solution to my problem Bandmath xml gpt, however I am yet to test this.