Engineering a remote survey of JET's divertor structure under conditions of restricted access using digital photogrammetry

JET is currently planning to install its new Gasbox Divertor remotely. In line with JET's policy and philosophy it was decided to survey the divertor structure remotely to confirm its position, shape and integrity prior to installing the new tile configuration. A survey to metrology standards is required, i.e. with sub-millimetre accuracy. While remote surveys have been carried out in the past, they have not been to this level of accuracy.