The packed identifier of a physical detector, stored as part of the hit (or digitisation) information, is returned unpacked by the routine GFHITS (or GFDIGI) which extracts the information from the JHITS or JDIGI structures, and may be used to retrieve the geometrical characteristics of the given detector.
If the detectors have been defined by the routine GSDETV, the geometrical information can be retrieved by the routines GFPATH and GLVOLU. GFPATH prepares the lists CHNAM and LNUM required by GLVOLU ( [GEOM001]), from the information preprocessed at initialisation time by the routine GGDETV and stored in the structure JSET