wherein a voltage or current pulse is initiated and terminated in accordance respectively with the pulse transmission and echo reception

Full Title

Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems > using reflection of acoustic waves (G01S15/66 takes precedence) > Systems determining the position data of a target > Systems for measuring distance only (indirect measurement G01S15/46) > using transmission of interrupted, pulse-modulated waves (determination of distance by phase measurement G01S15/32) > wherein a voltage or current pulse is initiated and terminated in accordance respectively with the pulse transmission and echo reception