Coincidence echo statistics

Abstract

Two scatterers at similar range give an echo which may appear to be due to a single scatterer. Methods for determining target strength that depend on resolving single scatterers may fail in this instance. Statistics associated with the described special case of coincidence are derived and illustrated by theoretical computation for the SIMRAD EK500 echo sounder system with the ES38B split-beam transducer resonant at 38 kHz. Connections to angle measurement in radar and swath bathymetry and to bottom-scattering-strength measurement are noted.