Capabilities and Limitations in Pulsed Surface Current Injection Techniques for EMP Testing

Direct injection of transient pulses on the surface of a test object is currently under investigation as a potential EMP surveillance tool. Since this test method is intended to complement existing EMP simulators, interior responses obtained with the surface current injection technique (SCIT) must be relatable to responses which are excited under simulated plane-wave illumination. As is usually the case for attempted replication of a desired environment, the fidelity of the technique represents a compromise between quality, cost and complexity. Previous studies of this approach were conducted with numerical models and simplified configurations (Refs. 1-3). This paper presents an evaluation of SCIT surveillance capabilities based upon experimental data for a realistic test object under simulated EMP plane-wave illumination and direct surface injection. Measured surface responses are compared to calculations obtained with the THREDE finite-difference code.