A submarine on patrol needs to know how far it can be detected by active sonar. In order for such sonar performance calculations to be useful the target strength (TS) of the submarine must be known. Measurements done in deep water indicate that TS can vary as much as 20 dB as a function of aspect angle. This corresponds to a doubling of the detection distance in a noise limited environment, and...

Introduction The estimation of fish abundance by the echo-integrator method requires a sonar that has been accurately calibrated. This may be done by measuring the signal received from a target whose acoustic properties are known. Several kinds of metal spheres have been used as calibration targets, in particular brass (Forbes, Simmonds and Edwards, 19801, copper (Foote, et a/., 1981) and tungs...

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Many surveillance tasks rely on the generation of stable, continuous tracks of objects of interest. Often, track continuity has a higher priority than track accuracy, as valuable information on the identity or the origin of an object is lost by each track drop. The main source of track fragmentation are missing detections due to a limited field of view or technical or topographical masking. In ...

A major premise upon which this paper by Macaulay was written is flawed as is the formulation (both conceptually and mathematically) of the scattering models. The formulation is actually an assemblage and adaptation of previously published approximate solutions rather than a generalization. The physics of the scattering isblurred through a multitude of empirical parameters. In order for this ne...