Osmic projection

A technology used by the Sontarans. It was available to them from at least the 12th century. An Osmic Projector was used by Commander Linx to travel 800 years into the future to procure advanced technology and skilled personnel to assist him in repairing his vessel. Use of the projector left a ghost-like figure of the projected being for some minutes after its use, traces of which were detectable to specialized equipment. ([DW: The Time Warrior] http://tardis.wikia.com/wiki/The_Time_Warrior )