TRACKER: A 3-D radio ray tracing code

TRACKER is a 3-D radio ray tracing code which has been designed to simulate high frequency radio wave propagation through a perturbed ionosphere. It is the centerpiece of a family of codes written for the Cray-1 computer whose purpose is to model radar systems for use in detecting and identifying ionospheric perturbations. TRACKER accepts as input a perturbation file that describes the shape of an acoustic pulse at a discrete set of points in space at various times since the pulse was initiated. Except for a sophisticated set of interpolation algorithms needed to approximate the pulse shape at an arbitrary point, the perturbation model is external to TRACKER. The features that distinguish TRACKER from other ray tracing codes are the physics models, the state-of-the-art computational algorithms, the structure and modularity of the code itself, the interactive operational mode, and the sophisticated graphical output.