A comparison is made of the signal‐to‐noise characteristics of synthetic‐aperture sonar and conventional sonar. For the synthetic‐aperture sonar case a design procedure is described which makes possible the choice of essentially any unambiguous range and any resolution. Often multiple beam receivers are required. It is shown for the synthetic‐aperture sonar case that the horizontal aperture is the major factor affecting area coverage rate. The comparisons are made with as many parameter values as spossible identical for both the synthetic‐aperture cases and the nonsynthetic‐aperture cases. If identical physical aperture dimensions are used and other parameters held to identical values, the synthetic‐aperture sonar gives higher signal‐to‐ratio than does the nonsynthetic‐aperture sonar primarily because the latter must operate at higher acoustic frequencies for which signal attenuation becomes extremely large. If the sonar systems are operated at the same frequency, then the nonsynthetic aperture sonar can give a higher signal‐to‐noise ratio only when its physical aperture is larger than that used in the synthetic‐aperture case.
Subject Classification: 30.82; 60.20.
