Under a combination of several Small Business Innovation Research (SBIR) contracts and Internal Research and Development (IR&D) funding, TSC has developed a comprehensive environmental modeling capability under the most general propagation conditions, in open sea or littoral environments. This capability consists of (a) propagation modeling in support of real-time and near-real-time applications; (b) sea and terrain clutter modeling capability; and (c) real-time, high fidelity elevation monopulse modeling capability against low elevation targets, in the presence of ocean waves or over variable terrain. TSC is currently developing methods to enhance radar performance based on estimates of its propagation environment.

Two example diagrams are propagation coverage diagrams generated (a) by the Navy Variable Terrain Radio Parabolic Equation (VTRPE) model, and (b) from a compressed database generated by TSC's Electro Magnetic Propagation Compressed Data Environment (EMPCODE) model. EMPCODE, developed under Phase I and II Navy SBIR topic N95-180, employs a topological compression algorithm to reduce the processing time of the data. The compression was applied to the VTRPE coverage diagram (a). Table 1 lists some of the relevant parameters, including the compression ratio. From the diagrams,it is evident that the 22:1 compression ratio does not result in material degradation in fidelity. The compression, which takes a few second to accomplish, facilitates efficient storage of large databases and can be used to reconstruct the data in real-time.

The additional examples show how TSC's real time monopulse model matches the monopulse measurements, computed over three different realizations of the sea surface at sea states 3 and 5. The individual realizations took several hours each to process - longer at higher radar frequencies. The real time model executes in less than one tenth of a millisecond per point, on the same computer, independently of radar frequency.