3-D Visualization of RF Propagation in Terrain

3-D visualization of multiple RF fields requires innovative display techniques to overcome a number of technical challenges, including surface polygon reduction for increased graphics speed, and discrimination of multiple overlapping surfaces. The innovation in the present proposal derives from the PI's recent development of a 3-D tactical display for the Navy in which the interaction of sonar acoustic energy radiation with the environment and ocean floor was modeled and visualized. Investigation of several volume visualization techniques in this research has shown that 1) iso-value contour surfaces, or isosurfaces, are an effective means for representing boundaries of interest in an energy field, 2) visibility and transparency control are essential for distinguishing overlapping or nested isosurfaces, 3) interactive manipulation of the view of the environment greatly enhances a user's comprehension of complicated volumetric structures. In Phase I, we will apply these principles to RF visualization by developing a prototype demonstration using a combination of the proposer's 3-D visualization library and an OpenGL-based scientific visualization toolkit. Both of these tools entail no run-time or development licenses and are portable across Unix platforms. We will employ components of the Automated Map-Based Intelligence Support System (AMBISS) to define-VHF transmitter and receiver characteristics and antenna patterns. The Terrain Integrated Rough Earth Model (TIREM) will be used to compute a volumetric grid of path loss between airborne and ground-based transmitters and receivers. In addition to employing the visualization principles described above, we will also investigate the feasibility and utility of two additional advanced visualization techniques: 1) application of transparent texture maps to identification of RE fields, and 2) application of triangle decimation algorithms to terrain and iso-value surfaces for improving graphics speed. The 3-D visualization techniques developed using the proposed objected-oriented design, license-free toolkits, and portable, industry-standard libraries can be readily applied to a variety of RF visualization applications across all Unix platforms. Com