AN/SQS-26 Interference: 'Fathometer-Type' Bottom Returns
NAVY UNDERWATER SOUND LAB NEW LONDON CT
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In the various models of the ANSQS-26 sonar, enough energy is transmitted and received via the vertical sidelobe response to allow these systems to receive discreet echoes from the ocean bottom. Such echoes are referred to as fathometer returns because their arrival times relate directly to multiples of the water depth. Although the ANSQS-26 receives incoherent bottom reverberation returning via this same path, this discussion treats only the coherent fathometer-type returns. These returns are typically observed on the CW portion of the ANSQS-26 storage display, and constitute regions of interference, the severity of which is a function of the water depth, the normal incidence bottom loss, and the specific SQS-26 equipment model. In this paper, the fathometer-type of interference is discussed generally, and some specific ANSQS-26 BX and ANSQS-26 AXR results from test area Bravo a one degree square centered at 25.5 deg N, 72.5 deg W are presented.
- Acoustic Detection and Detectors