Abstract:

During a recent shallow-water (200-m) experiment west of San Diego, two 120-m aperture hydrophone arrays were deployed from the R/P FLIP. One array was oriented in the vertical direction, while the second was deployed at a 45-deg tilt. A set of 13 tones, from 49 to 388 Hz, were transmitted from a 60-m-deep towed source traveling cross slope over a 6- km track. At CPA, the source was at endfire to the horizontal aperture of the tilted array. The data from both arrays were used to perform matched- field processing (MFP) for source localization in range and depth using replica vectors generated from a range-independent environmental model. In addition, the data from the tilted array were used to simultaneously localize the source in azimuth. The range and depth MFP biases of the two arrays agree quite well with one another and with analytical predictions from previous work. Here, those results are extended to successfully predict the offset bias in the MFP azimuth results, which reaches a maximum of 20 deg at endfire. [Work supported by ONR, Code 321(US).]