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A new method for the calculation of vector acoustic intensity from pressure microphone measurements has been applied to the aeroacoustic source characterization of an unheated, Mach 1.8 laboratory-scale jet. Because of the ability to unwrap the phase of the transfer functions between microphone pairs in the measurement of a radiating, broadband source, physically meaningful near-field intensity vectors are calculated up to the maximum analysis frequency of 32 kHz. The new intensity method is used to obtain a detailed description of the sound energy flow near the jet. The resulting intensity vectors have been used with a raytracing technique to identify the dominant source region over a broad range of frequencies. Additional aeroacoustics analyses provide insight into the frequency-dependent characteristics of jet noise radiation, including the nature of the hydrodynamic field and the transition between the principal lobe and sideline radiation. Nomenclature d = spacing between two microphones = nozzle exit diameter , = transfer function between microphones a and b I = time-averaged vector intensity p = acoustic pressure = acoustic pressure magnitude = acoustic pressure phase , ( ) = quadspectrum between microphones a and b 1 Associate Professor, Dept. of Physics and Astronomy, N283 ESC, AIAA Senior Member.