Estimating bearing angles by encoding ultrasonic transmissions at different frequencies

One of the main drawbacks of ultrasonic transducers is the difficulty to determine the bearing angle of echoes coming from an obstacle placed in front. Echoes often provide only the distance to the reflector inside the emission cone of the transducer, so some applications associate several transducers with the same scanning area to obtain more information about the common reflectors. This work proposes the use of encoded transmissions along a large bandwidth in order to estimate the bearing angle of echoes with only one transducer, even in cases with low signal-to-noise ratios.