Lookout Assist Device Feasibility Studies. Volume IV. Sonic Bearing Sensing Techniques and Requirements, Microphones, Wind Silencing, Automatic Detection, Magnetic Recorders, Spectrum Analyzers, Display System Design, Tentative Specifications for Lad System, Performance Estimates

摘要

The H-LAD system described represents a considerable step forward in the efficient reception and utilization of acoustic data at sea. Besides extending the ranges of detection of fog signals well beyond the capabilities of the unassisted human lookout, the H-LAD also permits more accurate interpretation of the data in all those aspects that are important to conning decisions. T-LAD and Unified Display Systems are also described which will add to the value of LAD by: (1) warning the ships personnel in a clear and unambiguous manner of the existence and position of intruders (2) presenting all pertinent data on the intruders to the conning officer in a highly efficient, recognizable, and collatable fashion. Section 1 contains a catalogue of all the principle techniques used in sonar for passive detection and measurement of bearing of an intruder and selects those techniques most effective for H-LAD. Section 2 describes and recommends an automatic detection system to be used with H-LAD. Section 3 recommends a recording and callout system to be used in common by the H-LAD and T-LAD and compares the selection with alternative techniques. Section 4 compares the advantages of various spectrum analyzer techniques and selects a simple technique to be used in the classification of sound signals with H-LAD. Section 5 describes the requirements imposed upon the Display System by H-LAD and suggests means of incorporating R-LAD data into the same display. Section 6 contains the specifications for a combined evaluation model H-LAD, T-LAD, and Unified Display System. (Author)