Detecting ultrasonic signals in a turbulent atmosphere: performance of different codes

Signal coding and pulse compression provide ultrasonic systems with the capability to obtain accurate measurements that are nearly independent of the conditions of operation. This property, together with the high robustness to noise also achieved with these techniques, are making possible the development of high reliability systems intended for outdoor operation. However, these systems must face new problems not found indoors, such as the effect of atmospheric turbulence on the shape of the emitted waveforms. This work presents a comparative analysis of the performance of different codes that are used to encode the signals of an ultrasonic sensory system designed to operate under strong turbulence conditions.