Side-looking multipulse sonar moving down cinder-block hallway
Rather than producing a single TOF reading per emission, the multipulse sonar produces multiple spikes by quickly resetting the sonar-detector integrator, thereby producing a spike density related to the echo amplitude. A side-looking sonar scans a cinder-block wall containing a door and window jambs. The resulting spikes have been processed to differentiate the first cinder-block wall, the cider-block surface and localize the window and door jambs. The red circles indicate the initial TOF values and illustrate the additional echo waveform data produced by the multipulse sonar.
Reference: R. Kuc: Recognizing retro-reflectors with an obliquely-oriented multi-point sonar and acoustic flow, Int. J. Robot. Res. 22(2), 129-145, (2003); doi:10.1177/0278364903022002004.