An Overview of the 1991 Reconnaissance Cruise of the Acoustic Reverberation Special Research Program

The Reconnaissance Cruise of the ONR Acoustic Reverberation Special Research Program (ARSRP) was conducted in July - August, 1991. The tracks were west of the Mid-Atlantic Ridge at approximately 26° N from 45° — 53° W. The seafloor in this region is rough with no or very thin sediment cover. The acoustic signals used were centered at 250 Hz with bandwidths up to +/- 40 Hz, the transmitter was a ten element, 5 wavelength, vertical array, the receiver was a 128 element, 64 wavelength, horizontal array. The ARSRP Reconnaissance Cruise was the first of two experiments in this area with the objective of determining the characteristics of low grazing angle bottom reverberation. The second is planned for 1994 and will use in situ arrays and sources, towed source and receiver arrays, bistatic receivers and high resolution bathymetry obtained during a 1993 Geophysical Cruise for the ARSRP. This paper provides an overview of the ARSRP Recon Cruise.