On ultrasonic image generation with biomimetic sonar head and narrow beam

Airborne ultrasonic images are not often used in practice, mainly because of the poor air propagation properties of ultrasonic frequencies and high necessary computation resources. The availability of powerful signal processors and the need to have solutions in some special environments, such as dark, smog or fog, require the reconsideration of airborne ultrasonic images, using classic or classic plus biomimetic processing techniques. The paper presents preliminary results of ultrasonic image generation and processing system by a biomimetic sonar head. The goals of the image processing are detection and object recognition. The transmitted and received signals (echoes) are processed by the blocks of the biomimetic sonar head. Experiments were conducted for eight cases, based on three main (similar) objects, and various image resolutions, 20×20 and 40×40. Images are generated by a discrete and uniform exploring approach, i.e. for each direction a burst is transmitted and echo signals are recorded and processed. The fixed working frequency is 40 kHz and the directivity of the receivers has narrow beams. The results are encouraging and suggest development and optimization of the proposed method.