Use of Spherical Objects as Calibrated Mine Hunting Sonar Targets

摘要

Solid, water-filled and air-filled spheres are investigated for suitability as calibrated targets for active mine hunting sonars operating in the range 10kHz to 200kHz. It is found that all solid and water-filled designs have target strengths that are strongly frequency-dependent, but some air-filled designs are not frequency dependent. It is found that thick-walled spherical glass floats are suitable for some frequency ranges, and thin-walled stainless steel spheres are suitable over the whole frequency range, if they are sufficiently well made and conditions allow their deployment.