NASA B-757 HIRF test series low power on-the-ground tests

The data acquisition phase of a program intended to provide data for the validation of computational, analytical and experimental techniques for the assessment of electromagnetic effects in commercial transports, for the checkout of instrumentation for following test programs, and for the support of protection engineering of airborne systems has been completed. The initial phase involved on-the-ground electromagnetic measurements. Measurements were made of the fields coupled into the aircraft interior and signals induced in select structures and equipment under controlled illumination by RF fields. A characterization of the ground was also performed to permit ground effects to be included in forthcoming computer modeling exercises. A series of fly-by experiments were conducted in early 1995 in which the NASA B-757 was flown in the vicinity of a Voice of America station (~25 MHz), a fixed transmitter driving a log periodic array (172 MHz), and an ASRF radar at Wallops Island (430 MHz). In this paper, the overall test program is defined with particular attention to the on-the-ground portion. The test rationale, test layout, and samples of the data are described. Samples of some inferences from the data that will be useful in protection engineering and EM effects mitigation will also be presented     

Tools and techniques for estimating high intensity RF effects

Tools and techniques for estimating and measuring coupling and component disturbance for avionics and electronic controls are described. A finite-difference-time-domain (FD-TD) modeling code, TSAR, used to predict coupling is described. This code can quickly generate a mesh model to represent the test object. Some applications as well as the advantages and limitations of using such a code are described. Facilities and techniques for making low-power coupling measurements and for making direct injection test measurements of device disturbance are also described. Some scaling laws for coupling and device effects are presented. A method for extrapolating these low-power test results to high-power full-system effects are presented