Localization of the moving object by echolocation

Abstract

Using the echolocation, bats can capture moving objects in real 3D space. Bats emit the frequency modulation sound and can accurately localize these objects from echoes. The object's range could be estimated from delay times between the emitted sound and echoes from objects. These positions in 2D space could be estimated from the difference between delay times at two ears, and the accuracy of localization was dependent on the range accuracy, which was dependent on the frequency width of the emitted sound, the signal-noise-ratio (SNR), and the Doppler shift. It has been shown that the previous proposed model could accurately estimate each range of static objects by using the frequency modulation sound at the low SNR. However, it is unknown whether this model could estimate the moving object in 2D space. In this study, the echoes were measured from the rotating pole by emitting intermittently the LFM sounds. These echoes were analyzed by using the Gaussian Chirplet filters with a carrier frequency compatible with emission sweep rates. It was clarified that this proposed model could track the moving object by estimating object's position in 2D space at each time.