Electromagnetic Propagation Characterization using Communication Networks

TSC proposes to estimate and display local propagation conditions (refractivity) using selected shipboard communication signals in real-time, i.e. estimate Refractivity-From-Communications (RFCOM). The proposed approach frames the problem as a non-linear least squares estimation problem involving measured communication signal level profiles, range dependent parameterized refractivity profiles and a parabolic wave equation solution model. Phase I demonstrates feasibility by implementing candidate techniques against simulated data and validating them using directly measured propagation data available from NSWCDD. Phase II will develop prototype code for a real time implementation and validate the code against field test data. Phase III will integrate this new capability into onboard communications systems and the Navy Integrated Tactical Environmental Sub-System (NITES). Outputs of Phase I are: a detailed algorithm description; MATLAB code; a measured signal requirements specification detailing the requirements placed on the communication systems in order to produce the require measurements; and feasibility assessments validating the method for selected cases and assessing potential performance in practical scenarios. Phase II outputs are prototype software and broad validation results based on field demonstration. Phase III outputs are requirements definition documentation, software design/development, system integration, and test efforts for integrating with NITES.