Definition

A type of SWATH(E) SOUNDING SYSTEM in which the equipment emits a timed PULSE of sound that is narrow in the fore-aft direction and wide in the across track direction.  The reflected sound is received by several RECEIVERs arranged as an ARRAY.  By use of SIGNAL processing of the SIGNAL received at combinations of the RECEIVERS a much larger number, potentially many hundreds, of ACOUSTIC receive BEAM angles are formed.  For each receive BEAM the time interval between emission and reception of the reflected sound is converted into a RANGE.  Geometry is then used to convert each RANGE and receive BEAM angle to DEPTHs and also to position these DEPTHs within the SWATH(E) on the SEAFLOOR.  MBES systems may also be referred to as beam-formers.