Abstract:

In August 1996 an experiment was performed southeast of Long Island, NY (40 30.16 N, 70 30.58 W) to examine water column effects on synthetic aperture sonar (SAS). Both the experiment and the pre-experimental modeling that guided the experiment will be presented. Salient features of the experimental equipment and procedure include the use of bottom mounted towers for stability, transmission frequencies of 6, 20, 75, and 129 kHz, reciprocal tower-to-tower transmissions, and receivers spaced over a 10-m horizontal and 6-m vertical aperture. First look results will be presented for a 24-h period that included a solibore event. Large variations in propagation conditions over time scales of minutes are evident in the data. The SAS relevant quantities to be extracted from this data set will be discussed. [Work supported by ONR.]