Brought to my attention by another individual
Technical Memorandum: MISSILE GUIDANCE: INTERFEROMETER HOMING USING BODY-FIXED ANTENNAS
Page 101
Said reference is: 49. "Terrier BT Trimode Feasibility Study," Surface Missile Systems Dept., JHU/APL MP2-117 (Nov 1967). This article is the only reference to it that appears online.
There may be other interesting references in the document, I haven't read through it yet myself
Technical Memorandum: MISSILE GUIDANCE: INTERFEROMETER HOMING USING BODY-FIXED ANTENNAS
Page 101
BT Trimode. A multimode version of the Terrier BT missile was proposed and studied. The original Terrier BT missi!e used beam-rider guidance. The proposal and studies considered adding an RF interferometer and IR seeker for certain specific environments. Details of this are provided in Ref. 49.
Said reference is: 49. "Terrier BT Trimode Feasibility Study," Surface Missile Systems Dept., JHU/APL MP2-117 (Nov 1967). This article is the only reference to it that appears online.
There may be other interesting references in the document, I haven't read through it yet myself