Patent ID: 8879360
Filing Date: 2014-11-04
Classification: G10K

Abstract:
1. A subsea sonar unit comprising: an acoustic transducer, the acoustic transducer transmitting an acoustic beam defining an acoustic propagation path for acoustic signals to or from the acoustic transducer; a housing comprising an oil filled part and positioned in the acoustic propagation path, the housing being acoustically transparent and having an outer surface with a known shape in said acoustic propagation path; a corrective lens, said corrective lens being mounted in said acoustic propagation path between said transducer and said oil filled part, an interface between the corrective lens and the oil filled part defining a first surface having a shape relative to a cross section of said acoustic beam in the acoustic propagation path that essentially corresponds to the known shape of said outer surface relative to said acoustic beam's cross section at said outer surface in said acoustic propagation path; and wherein the oil filled part is positioned between said interface and said outer surface.