Method of and apparatus for providing information as to the existence or position of objects.

摘要

A method of and apparatus for locating an object by stress wave energy reflection in which the wave energy is transmitted as a beam by transmitting transducer elements (10a to 10j), and is scanned through successive sectors of a field of view (2 0 ) by imposing differential transmission delays on transmitting signals fed to the elements (10a to 10j) by means of a delay line (19). Indicator signals are developed in receiving channels connected respectively to receiving transducers (28L, 28R) providing binaural characteristics, and transducer (28) providing monaural characteristics but collectively covering the field (2 0). The indicator means comprises any, or any combination, of audible means (34L, 34R, 34), visual means or tactile means the two latter providing coordinate displays, and the receiving means including spectral analysing means (f1-f7) for segregating the indicator signals into separate different frequency band, and delay means (d1-d7) for imposing differential delays compensating for transit time of wave energy reflection in the medium correlated with different range bands before coordinate display.