A Clutter-Removal Toolkit to Improve VLF Receive Fidelity

ABSTRACT: Reliable transmission and reception of messages to bomber, tanker and reconnaissance wing-command posts requires a high degree of robustness and redundancy in the event of a nuclear attack. One key feature of this transmission and reception capability is the VLF radio, capable of broadcasting worldwide by use of ground transmitters and propagating radio waves. Despite the challenges of launching a VLF signal, the VLF radio has a number of advantages including omni-directional long-range propagation, and low diffraction. Given the importance of reliable VLF communication, the Air Force needs a militarized VLF antenna designed for airborne use and capable of reliable operation in a Nuclear Command Control and Communications (NC3) environment. Despite the robustness of VLF transmission and reception there are still issues that impede a sensor"s ability to receive emergency-action messages effectively. These include the Electromagnetic Pulse from a local event, Ducted EMP through the aircraft structure, Aircraft Electromagnetic Interference, Nuclear Scintillation, Jamming and Natural atmospheric events such as lightning. SARA, using their extensive experience in both VLF sensor development and EMI\EMP mitigation proposes a two-pronged approach: advancement of VLF receive antenna magnetometers, and advancement in EMI\EMP reducing treatments, to meet the Air Force"s NC3 needs. BENEFIT: The successful completion of the Phase I program provides a baseline and defines the future development process of the VLF receive antenna system. It does this by defining the system inputs, the sensors current state of the art, possible future system performance, and demonstrates a new high payoff technique for noise and clutter cancellation. The Phase I program produces a base for a focused development effort for obtaining a new more capable VLF communication system for the Air Force"s Nuclear Command Control and Communications (NC3) needs.