Raytheon Company

Brian Filarsky

Ender E Barillas

William F Dixon

Jason Kyle

Arnaldo J Colon

A GNSS hostile environment simulator for accurate real-time processor & hardware in the loop (PHIL) simulations of a multiple antenna GNSSR/AJ system models antenna effects over the entire signal bandwidth allowing direct injection of the RF into the GNSSR. Computational efficiency is achieved by applying the antenna patterns in the frequency domain. To preserve the integrity of the antenna signals, the transmitter signals are generated over an extended period to push any residual ringing outside the update window. Efficiency is further enhanced by using a combination of single-precision and double-precision floating-point units to generate the samples of the transmitter signals with single-precision floating-point. All subsequent calculations are then computed in single-precision.

Global navigation satellite system (GNSS) hostile environment simulation

Computationally efficient mixed precision floating point waveform generation takes advantage of the high-speed generation of waveforms with single-precision floating point numbers while reducing the generally unacceptable loss of precision of pure single-precision floating point to generate any waveform that repeats in 2&#x3c0;. This approaches computes a reference phase in double precision as the modulus of the phase with 2&#x3c0; and then computes offsets to that value in single precision. The double precision reference phase is recomputed as needed depending on how quickly the phase grows and how large a machine epsilon is desired.

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Tucson, AZ, United States of America

Brian Filarsky