'''<INSTR>''' could be SHD for shocndisbelief, SHA for shocnawe or SHH for shocnhorror,
'''<YYMM>''' is the year and month, and
'''<filename>''' is the instrument abbreviation (SHA or SHD) followed by the date in YYYYMMDD format and the number of the image you've selectedacquisition.
===Advanced users guide ===