Two-dimensional simulations of wake vortex detection using Rass

A parallel code is developed to numerically simulate wake vortex detection using a Radio Acoustic Sounding System (RASS). The code is written in Fortran 90 with the Message Passing Interface (MPI) for parallel implementation. The numerical simulation solves simultaneously the linearized Euler equations for a non-uniform mean flow and the Maxwell equations for a non-homogeneous medium. The radar transmitter and receiver antennas are modeled using an array of point sources and a beamforming technique, respectively. Many features of the RASS are explored using the numerical simulation. First, a uniform mean flow is considered and the RASS simulation is performed for two different types of incident acoustic field: a short single frequency acoustic pulse and a continuous broadband acoustic source. Both monostatic and bistatic configurations are examined and their results are compared. Taylor and Oseen vortex velocity profiles are used as a vortex model, and the mean flow fields are reconstructed from the backscattered electromagnetic signal using the Abel transform. The effect of radar beam width is also shown.