Woomera, the aircraft was operated by Institut Geographique National, of Creil France from 1948 until the 80's. This outfit operated nine B-17's over the years, although I doubt that they ever operated them all at once.
One can only presume that the low acquisition cost of these aircraft, combined with incredible range, made them a cost-effective machine for low-utilisation survey work.
You can refresh your memory by referring to page 130 of "Balus - volume II", where there is a nice shot of the machine.
Never saw it myself, being just a yung 'un, but would love to have flown something like that.