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Three-Ship Mutual Interference Tests

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Preliminary rept. no. 2

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This is the second in a series of three reports to describe the results obtained from an analysis of data recorded during the ANSQS-26, three- ship, mutual interference sea tests, conducted during the period 19-25 July 1965 by the Key West Test and Evaluation Detachment. It was noted in the first preliminary report that two unexpected interferences were observed, namely, interference by off frequency ODT pulses and correlations against off frequency FM pulses. No new or unexpected influences or interferences have been noted during the subsequent analysis. The actual sea test log, recorded by the Key West Test and Evaluation Detachment during the test, has been corrected for errors identified during the analysis of recorded sea test data. Noted discrepancies between the log and actual results included frequency, transmit schedule, mode, beam orientation, and depression angle errors. Approximately 10 of the total number of events were found to have some type of error. The corrected log is included in Appendix A to this report. Sonar Performance i.e., Were the sonar systems operating properly during the tests. has been partially evaluated for the three ships. Several malfunctions have been noted, including both the transmit and receive sub-systems. These malfunctions include sudden changes in transmitting frequency and bandwidth, and variable times between pings in the triple ping mode. Beam misalignment between transmit and receive orientation was noted at the steeper tilt angles but has not yet been fully evaluated.

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  • Acoustic Detection and Detectors

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