This Phase I SBIR program exploits RTA-s recent development of an "Active Magnetic Field Sensor (AMFS)" to the problem of communication with submerged platforms and submarines. Since the AMFS has the potential for discrimination of electromagnetic signals in the ELF and VLF region of the spectrum for generating signals at these wavelengths and for discrimination of ambient background noise and clutter, it is an optimal device for use in underwater communications. The AMFS generates an intense focused magnetic flux with an overriding ELF modulation which can be hidden in a pseudo random noise (PRN) code pattern which propagates through the ocean. Detection of received signals is through use of nonlinear signal processing techniques. In a planned Phase II follows effort, a fieldable prototype system will be developed for Navy evaluation.
