It is a more accurate version of the ( VHF omnidirectional range ) / ( distance measuring equipment ) ( VOR / DME ) system that provides bearing and range information for military aviation , the DME portion of the TACAN system is available for civil use .
It is a more accurate version of the VHF omnidirectional range / distance measuring equipment ( VOR / DME ) system that provides bearing and range information for civil aviation . 
 At VORTAC facilities where a VOR is combined with a TACAN , the DME portion of the TACAN system is available for civil use .