| 摘要 |
PURPOSE:To prevent a system from being complicated or the like and remove a disadvantage that a long time is required for obtaining an image and a danger that a damage in vivo is generated by providing a ultrasonic wave generator, a sound collecting microphone, a reference signal generator and a correlator. CONSTITUTION:A modulating signal generator 17 generates a modulating signal in accordance with the command of a controller 15. The modulating signal modulates the signal of an oscillator 21 in a modulator 19 and gives a generated ultrasonic signal to a distributed sound source 23. A sound wave 25 emitted outside is reflected from a reflector 27 to become an echo 29, which returns to a microphone equipment 31. Signals thus obtained are sampled in time sequence to be stored into a memory 33. The results of many measurements are judged and unnecessary noise components are removed as required. On the other hand, a reference signal generator 35 synthesizes a reference signal corresponding to a direction or a position desired to be observed by an arithmetic processing represented by a given formula. A series of received signals are repeatedly supplied to an instrument 37, such as a digital correlator. Mutual correlations between the received signals and the generated reference signals are obtained while sequentially changing the estimation of the direction and position. Individual pieces of reflection data obtained are stored into a memory 41.
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